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Summary Report from Task 3 of MEWS Project at the Institute for Research in Construction – Hygrothermal Properties ofSeveral Building Materials

Kumaran, K.; Lackey, J.; Normandin, N.; van Reenen, D.; Tariku, F.

0

March 2002

IRC-RR-11

http://irc.nrc-cnrc.gc.ca/ircpubs

http://irc.nrc-cnrc.gc.ca/ircpubs

SUMMARY REPORT FROM TASK 3 OF MEWS PROJECT AT THE INSTITUTE FOR RESEARCH IN CONSTRUCTION

Hygrothermal Properties of Several Building Materials

Kumar Kumaran

John Lackey

Nicole Normandin

David van Reenen

Fitsum Tariku

March 2002

Reference:

Kumaran, M.K., Lackey, J., Normandin, N., van Reenen, D., and Tariku, F., (2002) "Summary Report from Task 3 of MEWS Project" Institute for Research in Construction, National Research Council, Ottawa, Canada, (NRCC-45369), pp. 1-68.

MEWS PROJECT REPORT T3-23: March 2002

SUMMARY REPORT FROM TASK 3 OF MEWS PROJECT AT THE INSTITUTE FOR

RESEARCH IN CONSTRUCTION

Hygrothermal Properties of Several Building Materials

IRC Research Team

Peter Beaulieu Mostafa Nofal

Mark Bomberg Nicole Normandin

Steve Cornick Mike Nicholls

Alan Dalgliesh Tim O’Connor

Guylaine Desmarais David Quirt

Reda Djebbar Madeleine Rousseau

Kumar Kumaran Nady Said

Michael Lacasse Mike Swinton

John Lackey Fitsum Tariku

Wahid Maref David van Reenen

Phalguni Mukhopadhyaya

MEWS Steering Committee

David Ritter, Louisiana Pacific Corporation Eric Jones, Canadian Wood Council Fred Baker, Fortifiber Corporation Gary Sturgeon, Masonry Canada Michael Bryner, EI DuPont de Nemours & Co

Sylvio Plescia, CMHC

Gilles Landry, Fiberboard Manufacturers Association of Canada

Fadi Nabhan, IRC, NRC Canada

Stephane Baffier, CPIA David Quirt, IRC, NRC Canada Paul Morris, Forintek Canada Corporation Kumar Kumaran, IRC NRC Canada Greg McManus, Marriott International Inc. Michael Lacasse, IRC NRC Canada Stephan Klamke, EIMA

Executive Summary This report summarizes the findings of MEWS Task Group 3 on the Properties of the following building

materials.

1. Oriented Strand Board

2. Plywood

3. Brick

4. Mortar

5. Stucco

6. Wood fibreboard

7. Composite wood siding

8. Water resistive barrier

9. Exterior grade gypsum board

10. EIFS base and finish coats and

11. Spray polyurethane foam

The properties that have been experimentally determined include:

1. Thermal conductivity of the dry material as a function of temperature

2. Water vapour permeability/permeance as a function of relative humidity

3. Equilibrium moisture content as a function of relative humidity/suction

4. Moisture diffusivity as function of moisture content

5. Water absorption coefficient

6. Air permeability/permeance

For the first eight materials, several products were tested to establish the range of properties shown by each material available in North American market. The main purpose of this investigation was to provide representative material properties as inputs for IRC’s hygrothermal model hygIRC.

Summary Report from Task 3 of MEWS i Hygrothermal Properties of Several Building Materials

Table of Contents 1 Introduction..........................................................................................................................................................1

1.1 Experimental Procedures.............................................................................................................................2 1.2 References...................................................................................................................................................7

2 Example Applications of Various Methods to determine the Hygrothermal Properties of Aerated Concrete....9 3 Representative Hygrothermal Properties of Plywood and OSB Products in North America ............................18 4 Air Permeances and Water Vapour Permeances of Nine Types of Water Resistive Barriers..........................26 5 Hygrothermal Properties of Six Bricks ..............................................................................................................30 6 Hygrothermal Properties of Mortar Mixes Used in North America....................................................................36 7 Hygrothermal Properties of Three Types of Stuccos Used in North America...................................................42 8 Hygrothermal Properties of Eight Fiberboard Sheathing Products...................................................................48 9 Hygrothermal Properties of Five Siding Products .............................................................................................58 10 Hygrothermal Properties of EIFS Base Coat + Finish Coat ..........................................................................66 11 Hygrothermal Properties of Exterior Grade Gypsum Board..........................................................................67 12 Water Vapour Permeability of a Spray Polyurethane Foam Insulation Product ...........................................68

Summary Report from Task 3 of MEWS 1 Hygrothermal Properties of Several Building Materials

1 Introduction

The Task Group 3 in MEWS project at the Institute for Research in Construction was struck to

systematically determine the hygrothermal properties of building products that are currently used in North

America. The main objective was to determine the range of each property for each set of products and provide that information as input to the computer model hygIRC, for parametric analyses.

At the first meeting on May 5 1998, the task group decided to concentrate on “materials out board of the

studs starting with sheathing”. As a result the following products were included in the investigation.

Product Name Number of

Products

Comments

OSB 6 The bulk densities were in the range 575 to 725 kg m-3

and varied from 10 to 11.5 mm. The strands included

aspen, poplar, birch as well as southern yellow pine.

Plywood 6 The bulk densities were in the range 400 to 600 kg m-3

and the thickness from 9.5 to 13 mm. The products were

certified as conforming to Canadian plywood

manufacturing standards CSA O151 Canadian Softwood

Plywood (CSP), or CSA O121 Douglas Fir Plywood

(DFP). These standards permit a variety of wood species

to be used in veneer plies, except that Douglas Fir is

required for the outer plies of CSA O121 DFP.

Fibreboard 8 Two of the products investigated were natural fiberboard

(no coating or facer) and four were coated with a thin layer

of black material on both major surfaces. One product

had a paper facer on one major surface while another one

had an aluminum foil facer. The nominal thickness of the

products varied between 11 mm and 13 mm. The

densities varied between 235 kg m-3 and 330 kg m-3.

Composite Wood

Siding

5 The substrates of three of the products were compressed

fiberboard, the fourth one OSB and the fifth one plywood.

All had vinyl coatings on one major surface. The thickness

of the products varied between 10.5 mm and 15.1 mm.

The densities varied between 580 kg m-3 and 930 kg m-3.

Water Resistive

Barrier

9 The products included paper based (rated 10 min or 30

min or 60 and # 15) and polymer based (spun-bonded

polyolifine, poly-acetate and polyethylene.


Brick 6 Clay brick, cement brick and calcium silicate brick are

included.

Mortar 4 Portland Cement-Lime Mortar and Masonry Cement

Mortar types N and S are included.

Stucco 3 Regular Lime Stucco , Regular Portland Stucco and

Acrylic Stucco.

EIFS 1 Polymer cement as the base coat and “Latex Acrylic with

Integral Colour and Texture” as the finish coat.

Sprayed

Polyurethane Foam

1 As applied on a 4' x 4' plywood substrate at a nominal

thickness of 2.25", in three passes of the spray.

Exterior Grade

Gypsum

1 Fibrous facers on either major surface.

Vinyl Siding 1 Strips are impenetrable to air and moisture.

For the parametric analyses hygIRC needs information on the following properties.

1. Thermal conductivity of the dry material as a function of temperature

2. Thermal conductivity as a function of moisture content

3. Water vapour permeability/permeance as a function of relative humidity

4. Equilibrium moisture content as a function of relative humidity

5. Moisture diffusivity as function of moisture content

6. Water absorption coefficient

7. Heat capacity of dry material (constant)

8. Heat capacity as a function of moisture content

9. Air permeability/permeance

1.1 Experimental Procedures Well-developed experimental procedures or international standard test procedures exist to determine the

properties listed above, except for the thermal conductivity and the heat capacity of moist materials. In the latter

cases combining rules [1] are used to estimate the properties from that for the dry material and water. The

principles of the experimental procedures that are used to determine the hygrothermal properties of building

materials in the present investigation are given below.

Thermal Conductivity of Dry Materials The heat conduction equation is directly used to determine the thermal conductivity of dry materials. Equipment

that can maintain a known unidirectional steady state heat flux (under known constant boundary temperatures)


across a flat slab of known thickness is used for the measurements. The most commonly used equipment is the

guarded hot plate apparatus or the heat flow meter apparatus. ASTM Standards C 177, Standard Test Method for

Steady-State Heat flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate

Apparatus and C518, Standard Test Method for Steady-State Heat flux Measurements and Thermal Transmission

Properties by Means of the Heat Flow Meter Apparatus are widely used for this purpose. The latter is used in the

present investigation. Similar standards are available from the International Standards Organization and the

European Union. In the ASTM Standards, the heat conduction equation is written for practical applications as:

λ = Q⋅l/(A⋅∆T) (1)

Where,

Q = Heat flow rate across an area A

l = Thickness of test specimen

∆T = Hot surface temperature – Cold surface temperature

The thermal conductivity calculated according to (1) is called apparent thermal conductivity. It is a function of the

average temperature of the test specimen.

Water Vapour Permeability/Permeance

The vapour diffusion equation is directly used to determine the water vapour permeability of building materials

[2]. The measurements are usually done under isothermal conditions. A test specimen of known area and

thickness separates two environments that differ in relative humidity (rh). Then the rate of vapour flow across the

specimen, under steady-state conditions (known rh’s as constant boundary conditions), is gravimetrically

determined. From these data the water vapour permeability of the material is calculated as:

δp = Jv⋅l/(A⋅∆p) (2)

Where,

Jv = Water vapour flow rate across an area A

l = Thickness of the specimen

∆p = Difference in water vapour pressure across the specimen surfaces

Often, especially for membranes and composite materials, one calculates the water vapour permeance, δl , of a

product at a given thickness from the above measurements as:

δl = Jv/(A⋅∆p) (3)

ASTM Standard E96, Test Methods for Water Vapour Transmission of Materials, prescribes two specific cases of

this procedure- a dry cup method that gives the permeance or permeability at a mean rh of 25 % and a wet cup


method that gives the permeance or permeability at a mean rh of 75 %. A new CEN Standard 89 N 336 E is being

developed in the European Union based on ISO standard. More recently a number of technical papers that deal

with various technical aspects, limitations and analyses of the experimental data of these procedures have

appeared in the literature [3-5].

For many hygroscopic materials, such as wood and wood products, the water vapour permeability/permeance is a

strong function of the local relative humidity and increases with rh. The ASTM Standard E 96 is being revised to

address this behaviour of building materials more quantitatively. For practical building applications, in addition to

the traditional dry and wet cup conditions, it is desirable to determine the permeance or permeability of

hygroscopic materials at a mean rh of 85 %. This can be done using the wet cup method of E96, but the rh in the

humidity chamber shall be maintained at 70 %.

Sorption/Desorption Isotherm

For sorption measurements, the test specimen is dried at an appropriate drying temperature to constant mass.

While maintaining a constant temperature, the dried specimen is placed consecutively in a series of test

environments, with relative humidity increasing in stages, until equilibrium is reached in each environment.

Equilibrium in each environment is confirmed by periodically weighing the specimen until constant mass is

reached. From the measured mass changes, the equilibrium moisture content at each test condition can be

calculated and the adsorption isotherm drawn.

The starting point for the desorption measurements is from an equilibrium condition very near 100% RH. While

maintaining a constant temperature, the specimen is placed consecutively in a series of test environments, with

relative humidity decreasing in stages, until equilibrium is reached in each environment. Equilibrium in each

environment is confirmed by periodically weighing the specimen until constant mass is reached. Finally, the

specimen is dried at the appropriate temperature to constant mass. From the measured mass changes, the

equilibrium moisture content at each test condition can be calculated and the desorption isotherm drawn.

A new CEN standard 89 N 337 E is under development for the determination of “Hygroscopic Sorption Curve.”

ASTM C16 Committee also is developing a standard.

Suction Isotherm:

The test specimens are saturated with water under vacuum. Those are then introduced in a pressure plate

apparatus that can maintain pressures up to 100 bar for several days. The plates in perfect hygric contact with the

specimens extract water out of the pore structure until an equilibrium state is established. The equilibrium values

for moisture contents in the specimens and the corresponding pressures (measured as the excess over

atmospheric pressure; the negative of this value is referred to as the pore pressure while the absolute value is the

suction) are recorded. The equilibrium pressure, ph, can be converted to a relative humidity, ϕ, using the following

equation:


hpρRTMln −=ϕ (4)

Where,

M = the molar mass of water

R = the ideal gas constant

T = the thermodynamic temperature and

ρ = the density of water

A Nordtest Technical Report [6] briefly describes a procedure for pressure plate measurements and reports the

results from an interlaboratory comparison. No standard procedure is yet developed for the determination of

suction isotherm. Also, the suitability of the pressure plate method and equation (4) for determining the

equilibrium moisture content of wood above 95% relative humidity has not been independently verified.

Moisture Diffusivity:

Moisture diffusivity, Dw, defines the rate of movement of water, Jl , within a material, induced by a water

concentration gradient according to the following equation:

Jl = - ρ0 Dw grad u (5)

Where,

ρ0 = density of the dry material

u = moisture content expressed as mass of water / dry mass of material

In the experimental procedure, liquid water in contact with one surface of a test specimen is allowed to diffuse into

the specimen. The distribution of moisture within the specimen is determined as a function of time at various

intervals until the moving moisture front advances to half of the specimen. Gamma spectroscopy is used as the

experimental technique. The data are analyzed using the Boltzmann transformation [7,8 ] to derive the moisture

diffusivity as a function of moisture content.

There is no standard test procedure for the determination of moisture diffusivity. There are many publications in

the literature that describe the technical and experimental details [9-12].


Water Absorption Coefficient:

One major surface of each test specimen is placed in contact with liquid water. The increase in mass as a result

of moisture absorption is recorded as a function of time. Usually, during the initial part of the absorption process a

plot of the mass increase against the square root of time is linear. The slope of the line divided by the area of the

surface in contact with water is the water absorption coefficient1.

A new CEN Standard 89 N 370 E on the determination of water absorption coefficient is under development.

Air Permeability/ Permeance:

Test specimens with known areas and thickness are positioned to separate two regions that differ in air pressure

and the airflow rate at a steady state and the pressure differential across the specimen are recorded. From these

data the air permeability, ka is calculated as:

ka = Ja⋅l/(A⋅∆p) (6)

Where,

Ja = Air flow rate across an area A

l = Thickness of the specimen

∆p = Difference in air pressure across the specimen surfaces

Often, especially for membranes and composite materials, one calculates the air permeance, Ka , of a product at

a given thickness from the above measurements as:

Ka = Ja/(A⋅∆p) (7)

ASTM Standard C 522, Standard Test Method for Airflow Resistance of Acoustical Materials prescribes a method

based on this principle. Bomberg and Kumaran[13] have extended the method for general application to building

materials.

1 When this method was applied to membranes, the membranes were put is perfect hygric contact with a substrate such as OSB.


1.2 References

1. Li, C. C., "Thermal Conductivity of Liquid Mixtures," AIChE Journal, Vol. 22, No. 5, pp 927-930, 1976.

2. Joy, F. A. and Wilson, A. G., “Standardization of the Dish Method for Measuring Water Vapour Transmission,”

Proceedings of the International Symposium on Humidity and Moisture, Washington, D. C., Vol. 4, Chapter

31, 1963, pp 259-270.

3. Hedenblad, G., “Moisture Permeability of Some Porous Building Materials,” Proceedings of the 4th

Symposium, Building Physics in the Nordic Countries, Espoo,Volume 2, 1996, 747-754.

4. Hansen, K. K. and Lund, H. B., “Cup Method for Determination of Water Vapour Transmission Properties of

Building Materials. Sources of Uncertainty in the Method,” Proceedings of the 2nd Symposium , Building

Physics in the Nordic Countries, Trondheim, 1990, pp 291-298.

5. Lackey, J. C., Marchand, R. G., and Kumaran, M. K., “A Logical Extension of the ASTM Standard E96 to

Determine the Dependence of Water Vapour Transmission on Relative Humidity,” Insulation Materials:

Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American

Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470. Also Kumaran, M. K., “An

Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of

Water Vapour Transmission Properties”, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581,

1998.

6. Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane," Nordtest

Technical Report 367, Danish Building Research Institute, 1998, p 63.

7. Bruce, R. R. and Klute, A, "The Measurement of Soil Diffusivity," Soil Science Society of America

Proceedings. Vol. 20, pp. 251-257, 1956.

8. Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine from gamma ray

absorption measurements," Collected Papers in Heat Transfer, 1989 : Winter Annual Meeting of the ASME

(San Francisco, CA, USA, 1989) pp. 179-183, 1989(ASME Heat Transfer Division vol. 123).

9. Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of Thermal

Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.

10. Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density distribution and

moisture distribution in building materials," Moisture and Humidity: Measurement and Control in Science and

Industry : Proceedings of International Symposium (Washington, D.C., USA, 1985), pp. 485-90, 1985.


11. Filip Descamps., "Continuum and Discrete Modelling of Isothermal Water and Air Transfer in Porous Media,"

Ph. D. Thesis, Katholieke Uniersity, Belgium, pp. 57-107, 1997.

12. Pel, L., "Moisture Transport in Porous Building Materials," Ph. D. Thesis, Eindhoven University of

Technology, the Netherlands, pp. 47-80, 1995.

13. Bomberg, M. T.and Kumaran, M.K., " A Test method to determine air flow resistance of exterior membranes

and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-235,1986.


2 Examples of Applications of Various Methods to determine the Hygrothermal Properties of Aerated Concrete

The test conditions reported in this section for different test methods are generally

followed throughout the project. Also, the procedures used in this section for data reduction

and analyses are followed for all materials in this report.

The test specimens used for various measurements reported here are taken from one block of aerated concrete, approximately 1’ X 1’ x 1.5’ in size.

Density: (460 ± 15) kg m-3

Heat Capacity (According to International Energy Agency Annex 24 Report2): 840 J K-1 kg-1

Thermal Conductivity: Measurements are according to ASTM Standard C518; 30 cm X 30 cm specimens are used in these

measurements. The temperatures of the plates are maintained within 0.02 °C for these measurements, during a

steady state for 12 h.

Table 2.1: Thermal Conductivity of Aerated Concrete.

Specimen Thickness

mm

Hot Plate Temperature

°C

Cold Plate Temperature

°C

Conductivity

W m-1 K-1

24.24 39.58 9.75 0.121

24.24 19.16 -9.40 0.119

Note: The heat flow meter apparatus is built to measure the heat transmission characteristics of insulating

materials and for those materials the measurement uncertainties are within 2 %; aerated concrete is more

conductive than traditional insulation and the large heat fluxes measured may give measurement uncertainties as

high as 5 %.

2 M K Kumaran, Final Report, Volume 3, “Material Properties”, International Energy Agency Annex 24 Report, Published by K. U. –Leuven Belgium, 1996


Sorption – Desorption Measurements3: Up to eight specimens, 41 mm X 41 mm X 6 mm each are used in these measurements; the numbers in

parentheses indicate the experimental uncertainties.

Sorption:

Table 2.2: Sorption data for Aerated Concrete.

RH, % Temperature, °C Moisture Content, kg kg-1

100, total saturation Lab at 22 (1) 1.72 (0.01), eight specimens

100, capillary saturation Lab at 22 (1) 0.83 (0.02), six specimens

88.1 (1) 23.0 (0.1) 0.050 (0.002), three specimens

71.5 (1) 23.0 (0.1) 0.021 (0.001), three specimens

50.6 (1) 23.0 (0.1) 0.011 (0.001), three specimens

Desorption:

Table 2.3. Desorption data for Aerated Concrete.

RH, % Temperature, °C Moisture Content, kg kg-1

99.99 (0.01) Lab at 22 (1) 0.92 (0.12), eight specimens



99.93 (0.01) Lab at 22 (1) 0.75 (0.06), eight specimens 99.85 (0.01) Lab at 22 (1) 0.72 (0.05), eight specimens 99.78 (0.01) Lab at 22 (1) 0.70 (0.05), eight specimens 99.71(0.01) Lab at 22 (1) 0.68 (0.04), eight specimens 99.63 (0.01) Lab at 22 (1) 0.66 (0.04), eight specimens 99.47(0.01) Lab at 22 (1) 0.64 (0.04), eight specimens 98.90 (0.01) Lab at 22 (1) 0.55 (0.02), six specimens 97.81 (0.01) Lab at 22 (1) 0.34 (0.05), six specimens

88.1 (1) 23.0 (0.1) 0.063 (0.001), three specimens

71.5 (1) 23.0 (0.1) 0.022 (0.001), three specimens

50.6 (1) 23.0 (0.1) 0.011 (0.001), three specimens

3 In the hygroscopic range, the measurements are done using the proposed procedure for ASTM Standard C1498, which in turn is based on CEN 89 N 337 E, “Hygroscopic Sorption Curve”; at the higher range the pressure plate method is used. Details of the pressure plate method are given by: Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane," Nordtest Technical Report 367, Danish Building Research Institute, 1998, p 63.


Water Vapour Transmission (WVT) Rate measurements4: For each test condition, 3 circular specimens, each 15 cm in diameter, are used.

Table 2.4. Dry Cup Measurements on Aerated Concrete Specimens: The numbers in parentheses indicate the experimental uncertainties

Specimen Thickness

mm Chamber RH

% Chamber Temperature

°C WVT Rate kg m-2 s-1

20.11 50.6 (1) 23.0 (0.1) 1.09E-06 (5.5E-09)

20.56 50.6 (1) 23.0 (0.1) 1.14E-06 (5.6E-09)

20.44 50.6 (1) 23.0 (0.1) 1.03E-06 (4.0E-09)

20.11 71.5 (1) 23.0 (0.3) 1.69E-06 (6.0E-09)

20.56 71.5 (1) 23.0 (0.3) 1.79E-06 (3.3E-09)

20.44 71.5 (1) 23.0 (0.3) 1.63E-06 (5.3E-09)

20.11 88.1 (1) 23.0 (0.3) 2.18E-06 (6.5E-09)

20.56 88.1 (1) 23.0 (0.3) 2.30E-06 (4.4E-09)

20.44 88.1 (1) 23.0 (0.3) 2.23E-06 (5.6E-09)

Table 2.5. Wet Cup Measurements on Aerated Concrete Specimens: The numbers in parentheses indicate the experimental uncertainties

Specimen Thickness

mm Chamber RH

% Chamber Temperature

°C WVT Rate kg m-2 s-1

20.29 71.7 (1) 23.0 (0.3) 1.30E-06 (1.7E-08)

20.34 71.7 (1) 23.0 (0.3) 1.40E-06 (1.4E-08)

20.11 71.7 (1) 23.0 (0.3) 1.49E-06 (1.5E-08)

20.29 87.8 (1) 23.0 (0.2) 1.13E-06 (1.5E-08)

20.34 87.8 (1) 23.0 (0.2) 9.60E-07 (1.0E.08)

20.11 87.8 (1) 23.0 (0.2) 9.69E-07 (1.0E.08)

The average thickness of still air in the cups is 11 mm

4 Measurements are done as described by: Lackey, J. C., Marchand, R. G., and Kumaran, M. K., “A Logical Extension of the ASTM Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative Humidity,” Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470.


Derived Water Vapour Permeability5

Table 2.6. The dependence of water vapour permeability of Aerated Concrete on relative humidity.

RH, % Permeability

kg m-1 s-1 Pa-1 RH, % Permeability

kg m-1 s-1 Pa-1 10 1.12E-11 60 2.76E-11 20 1.33E-11 70 3.34E-11 30 1.59E-11 80 4.07E-11 40 1.91E-11 90 5.00E-11 50 2.29E-11 100 6.21E-11

The relation between WVT and Chamber RH is shown in Figure 2.1.

Rank 1 Eqn 8002 [Exponential] y=a+bexp(-x/c)

r2=0.993 DF Adj r2=0.992 FitStdErr=1.17e-07 Fstat=965

a=-7.41e-07 b=7.54e-07 c=-61.21

0 20 40 60 80 100CHAMBER RH, %

0

5e-07

1e-06

1.5e-06

2e-06

2.5e-06

3e-06

3.5e-06

W V

T R

ate,

kg

m-2

s-1

Figure 2.1. All data are interpreted as dry cup measurements; RH inside the cup is “zero” and chamber RH is the RH outside the cup.

The numeric summary of the analyses is listed below. The commercial software package called TableCurve2 is

used for the curve fit. The terminology below is from the package.

5 The analysis is done as described in : Kumaran, M. K., “An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of Water Vapour Transmission Properties”, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581, 1998.


The equation that represents the relation between x = chamber RH and y = WVT rate is [Exponential] y= a + b

exp(-x/c)

r2 , Coefficient of Determination = 0.993

Fit Std Error = 1.7E-07

F-value = 965

Parameter. Value Std Error t-value 90% Confidence Limits

a -7.41e-07 2.1e-07 -3.5 -1.12e-06 -3.69e-07

b 7.54e-07 1.9e-07 4.0 4.23e-07 1.08e-06

c -61.2 7.5 -8.1 -74.5 -47.9

From the above statistics, the estimated uncertainty in the derived value of the permeability may be up to 28 %.

This type of uncertainty is quite common for building products that are not homogeneous.


Water Absorption Coefficient6: Five test specimens, 5 cm X 5 cm X 5 cm each, were used in these measurements. Water is maintained at (22 ± 1) °C. The numbers in parentheses give the standard deviations.

Table 2.7. Water absorption data for Aerated Concrete.

Square Root of

time, s½ Water Absorption

kg m-2 7.75 0.93 (0.13)

13.42 1.24 (0.17) 17.32 1.41 (0.21) 24.49 1.73 (0.25) 30.00 1.96 (0.29) 38.73 2.29 (0.34) 45.83 2.55 (0.37) 54.77 2.87 (0.44) 64.81 3.20 (0.47) 73.48 3.48 (0.53) 81.24 3.71 (0.56) 91.65 4.05 (0.62) 101.00 4.31 (0.69)

Linear regression using all the data from the first linear part of the absorption process for the five specimens gives: Water Absorption Coefficient for the major surfaces = 0.036 ± 0.002 kg m-2 s-½.

6 The procedure used is based on: CEN/TC 89/WG 10 N95 – Determination of water absorption coefficient, 1994-07-07.



Gamma ray method7 is used to measure the distribution of moisture in three test specimens, 5 cm X 30 cm X 2.4 cm each, during the moisture uptake through the edge. The principle of the methodology is described by Kumaran et. al8. Marchand and Kumaran9 have reported the procedure used for the data reduction.

The running average method that is described by Marchand and Kumaran gives the characteristic curve

shown in Figure 2.2, for this aerated concrete. Several hundreds of data pairs obtained on the three test specimens, in 36 sets of measurements over a period of seven days are included in the analysis.

0

50

100

150

200

250

300

0 0.0001 0.0002 0.0003 0.0004 0.0005 0.0006

Running Avg. Boltzmann Variable, m s-½

Run

ning

Avg

. Moi

stur

e C

onte

nt, k

g m

-3

Figure 2.2. The characteristic curve for aerated concrete resulted from moisture uptake and distribution measurements.

7 Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density distribution and moisture distribution in building materials," Moisture and Humidity: Measurement and Control in Science and Industry : Proceedings of International Symposium (Washington, D.C., USA, 1985), pp. 485-90, 1985. 8 Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine from gamma ray absorption measurements," Collected Papers in Heat Transfer, 1989 : Winter Annual Meeting of the ASME (San Francisco, CA, USA, 1989) pp. 179-183, 1989(ASME Heat Transfer Division vol. 123). 9 Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of Thermal Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.


The moisture diffusivity derived from the above characteristic curve is given in Table 2.8.

Table 2.8. The dependence of moisture diffusivity of Aerated Concrete on moisture content.

Moisture Content

kg kg-1

Diffusivity

m2 s-1

Moisture Content

kg kg-1

Diffusivity

m2 s-1

0.087 8.72E-09 0.326 3.44E-09

0.109 5.47E-09 0.348 3.64E-09

0.130 4.32E-09 0.370 3.91E-09

0.152 3.76E-09 0.391 4.29E-09

0.174 3.44E-09 0.413 4.81E-09

0.196 3.26E-09 0.435 5.56E-09

0.217 3.16E-09 0.457 6.71E-09

0.239 3.12E-09 0.478 8.71E-09

0.261 3.13E-09 0.500 1.3E-08

0.283 3.19E-09 0.522 2.89E-08

0.304 3.29E-09 0.543 5.15E-08

Note: The area enclosed by the characteristic curve in Figure 2.2 is ~ 0.033 kg m-2 s-½ and this value is

very close to the water absorption coefficient = 0.036 kg m-2 s-½ that was directly determined. This should be the

case and the correspondence between the two shows the internal consistency of the two methods. However, the

uncertainty in the derived moisture diffusivity is estimated to be as high as 30 to 50 %.


Air Permeability: Bomberg and Kumaran10 have reported the principle of the method used in these measurements.

Appendix XIII of the Client Report to ASHRAE, B-1115.3 “A Thermal and Moisture Transport Property Database

for Common Building and Insulating Materials – 1018-RP” dated 1 April 1999 reports the details. Three circular

test specimens, each approximately 15 cm in diameter, are used in these measurements. The measurements are

conducted at a temperature = (22 ± 1) ° C.

The summary of the statistical analyses of all data obtained from two series of measurements on each

specimen is shown in Figure 2.3 as three separate sets.

0

0.05

0.1

0.15

0.2

0.25

0 100 200 300 400 500 600 700 800

Pressure Difference (Pa)

Flow

, l m

-2 s

-1

Data Points Mean PermeanceUpper Confidence Interval Lower Confidence Interval

Figure 2.3. The dependence of airflow rate on pressure difference for aerated concrete.

For the range of pressure differences between 25 Pa and 700 Pa, the flow rate linearly varies with the pressure

difference. The air permeability is (4.9 ± 2.6) E-09 kg m-1 Pa-1 s-1.

10 Bomberg, M. T. and Kumaran, M.K., " A Test method to determine air flow resistance of exterior membranes and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-235,1986.


3 Representative Hygrothermal Properties of Plywood and OSB Products in North America

Background:

Ten plywood and seven OSB products were acquired for the investigation. These were either supplied by

the partners or purchased in consultation with experts. As reported at the Task Group 3 meeting in September

1998, two series of screening tests were conducted on all:

Water absorption rate through the major surfaces

Water vapour permeability between 70 % and 100 % RH

Based on the screening tests, and as agreed upon by the MEWS members, four plywood and four OSB

products were chosen as follows: two to represent the extremes and two from the middle range.

General Physical Properties:

The bulk densities, ρ, of the plywood products were in the range 400 to 600 kg m-3 and that for OSB 575

to 725 kg m-3. The thickness for the former varied from 9.5 to 13 mm and for the latter from 10 to 11.5 mm. The

heat capacity of both products, according to the IEA Annex 24 report is approximately 1880 J K-1 kg-1.

Thermal conductivity of dry materials:

The report T3-08 listed the results on the thermal conductivites of 12 test specimens each of plywood and

OSB at two mean temperatures (nominal 0 and 24 °C). The average temperature coefficient of thermal

conductivity is 2.1 x 10-4 W m-1 K-2 for plywood and 2.0 x 10-4 for OSB. Figure 3.1 and Figure 3.2 show the

dependence of thermal conductivity (W m-1 K-1), λ (nominal temperature 24°C), on bulk density, ρ, for plywood

and OSB respectively. Linear relations may approximate the dependence:

λ = a + b ρ

For plywood, a = 0.010 W m-1 K-1 and b = 1.67x10-4 (W m-1 K-1 )/ (kg m-3) and

For OSB, a = -0.0339 W m-1 K-1 and b = 2.05x10-4 (W m-1 K-1 )/ (kg m-3)


0.07

0.08

0.09

0.1

0.11

0.12

0.13

350 450 550 650

DENSITY, kg m-3

CO

ND

UC

TIVI

TY, W

m-1

K-1

Figure 3.1. Dependence of the thermal conductivity of plywood on density (at 24 °C)

0.07

0.08

0.09

0.1

0.11

0.12

0.13

550 600 650 700 750

DENSITY, kg m-3

CO

ND

UC

IVIT

Y, W

m-1

K-1

Figure 3.2. Dependence of the thermal conductivity of OSB on density (at 24 °C)


Water Vapour Permeability:

As presented in the report T3-05, the range of the water vapour permeabilities for the two products is as

follows:

Table 3.1. Water Vapour Permeability of Plywood

RH, % Permeability

kg m-1s-1 Pa-1 Lower Limit Upper Limit

20 4.22E-13 5.43E-13

30 6.99E-13 8.99E-13

40 9.73E-13 1.25E-12

50 1.38E-12 1.77E-12

60 2.19E-12 2.81E-12

70 3.85E-12 4.95E-12

80 7.02E-12 9.03E-12

90 1.28E-11 1.65E-11

100 2.31E-11 2.97E-11

Table 3.2. Water Vapour Permeability of OSB

RH, % Permeability

kg m-1s-1 Pa-1 Lower Limit Upper Limit

20 1.76E-13 2.05E-13

30 3.96E-13 4.63E-13

40 7.04E-13 8.23E-13

50 1.11E-12 1.29E-12

60 1.60E-12 1.87E-12

70 2.19E-12 2.56E-12

80 2.88E-12 3.37E-12

90 3.66E-12 4.28E-12

100 4.56E-12 5.33E-12



From detailed measurements on spatial and temporal distribution of moisture in test specimens during a

moisture uptake process across the edges, the following ranges are derived for the moisture diffusivity.

Table 3.3. Moisture Diffusivity of Plywood

Moisture Content

Diffusivity (Lower)

Diffusivity (Upper)

Moisture Content Diffusivity (Lower)

Diffusivity (Upper)

kg m-3

m2 s-1

m2 s-1

kg m-3

m2 s-1

m2 s-1

10 1.94E-08 2.86E-08 210 4.93E-09 5.39E-09 20 1.67E-08 2.26E-08 220 4.45E-09 4.88E-09 30 1.38E-08 1.74E-08 230 3.98E-09 4.38E-09 40 1.10E-08 1.30E-08 240 3.55E-09 3.92E-09 50 8.45E-09 9.52E-09 250 3.19E-09 3.52E-09 60 6.34E-09 6.99E-09 260 2.88E-09 3.19E-09 70 4.77E-09 5.29E-09 270 2.64E-09 2.91E-09 80 3.82E-09 4.26E-09 280 2.43E-09 2.69E-09 90 3.42E-09 3.79E-09 290 2.25E-09 2.50E-09 100 3.45E-09 3.79E-09 300 2.09E-09 2.33E-09 110 3.79E-09 4.14E-09 310 1.93E-09 2.16E-09 120 4.31E-09 4.67E-09 320 1.78E-09 1.98E-09 130 4.89E-09 5.28E-09 330 1.62E-09 1.81E-09 140 5.43E-09 5.84E-09 340 1.46E-09 1.65E-09 150 5.85E-09 6.29E-09 350 1.32E-09 1.50E-09 160 6.10E-09 6.58E-09 360 1.20E-09 1.37E-09 170 6.15E-09 6.66E-09 370 1.11E-09 1.26E-09 180 6.04E-09 6.56E-09 380 1.04E-09 1.18E-09 190 5.77E-09 6.28E-09 390 9.59E-10 1.11E-09 200 5.39E-09 5.87E-09 400 8.70E-10 1.01E-09


Table 3.4. Moisture Diffusivity of OSB

Moisture Content

Diffusivity (Lower)

Diffusivity (Upper)

Moisture Content Diffusivity (Lower)

Diffusivity (Upper)

kg m-3

m2 s-1

m2 s-1

kg m-3

m2 s-1

m2 s-1

10 9.05E-09 1.78E-08 310 3.58E-10 3.79E-10 20 4.39E-09 6.78E-09 320 3.52E-10 3.73E-10 30 2.88E-09 3.90E-09 330 3.46E-10 3.67E-10 40 2.13E-09 2.66E-09 340 3.41E-10 3.61E-10 50 1.70E-09 2.00E-09 350 3.36E-10 3.56E-10 60 1.41E-09 1.60E-09 360 3.31E-10 3.52E-10 70 1.21E-09 1.33E-09 370 3.27E-10 3.48E-10 80 1.05E-09 1.15E-09 380 3.22E-10 3.44E-10 90 9.38E-10 1.01E-09 390 3.18E-10 3.40E-10 100 8.45E-10 9.12E-10 400 3.14E-10 3.36E-10 110 7.71E-10 8.32E-10 410 3.11E-10 3.33E-10 120 7.11E-10 7.67E-10 420 3.07E-10 3.30E-10 130 6.61E-10 7.14E-10 430 3.04E-10 3.27E-10 140 6.19E-10 6.69E-10 440 3.01E-10 3.25E-10 150 5.83E-10 6.31E-10 450 2.98E-10 3.22E-10 160 5.53E-10 5.98E-10 460 2.95E-10 3.20E-10 170 5.27E-10 5.70E-10 470 2.92E-10 3.18E-10 180 5.05E-10 5.45E-10 480 2.89E-10 3.16E-10 190 4.85E-10 5.23E-10 490 2.87E-10 3.14E-10 200 4.67E-10 5.03E-10 500 2.84E-10 3.12E-10 210 4.52E-10 4.85E-10 510 2.82E-10 3.10E-10 220 4.38E-10 4.70E-10 520 2.79E-10 3.08E-10 230 4.25E-10 4.55E-10 530 2.77E-10 3.07E-10 240 4.14E-10 4.43E-10 540 2.75E-10 3.05E-10 250 4.04E-10 4.31E-10 550 2.73E-10 3.04E-10 260 3.95E-10 4.20E-10 560 2.71E-10 3.02E-10 270 3.86E-10 4.10E-10 570 2.69E-10 3.01E-10 280 3.78E-10 4.02E-10 580 2.67E-10 3.00E-10 290 3.71E-10 3.93E-10 590 2.66E-10 2.99E-10 300 3.64E-10 3.86E-10 600 2.64E-10 2.97E-10



Table 3.5. Water Absorption Coeficient of Plywood and OSB

Absorption Coefficient (Across the major surfaces)

kg m-2 s-½ plywood OSB Average 0.0026 0.0022 Standard

deviation

0.0013

0.0011

Air Permeance:

Both products are very airtight materials. Measurements on three test specimens of each of the six

products for either material gave the following results.

Plywood: Air permeance varies between 1.3 x 10-4 and 1.0 x 10-2 litre (75 Pa)-1 m-2 s-1.

OSB: Air permeance varies between 6.6 x 10-4 and 1.4 x 10-2 litre (75 Pa)-1 m-2 s-1.

Results on individual products are listed below.

Table 3.6. Air Permeance of Plywood and OSB

Plywood OSB

Product No. litre (75 Pa)-1 m-2 s-1 litre (75 Pa)-1 m-2 s-1

1 (2.1 ± 2.0) • 10-3 (7.7 ± 3.9) • 10-3 2 (3.0 ± 3.6) • 10-3 (6.6 ± 4.3) • 10-4 3 (1.6 ± 1.7) • 10-3 (1.9 ± 1.8) • 10-3 4 (2.4 ± 0.2) • 10-3 (1.4 ± 0.1) • 10-2 5 (1.0 ± 1.2) • 10-2 (3.2 ± 2.4) • 10-3 6 (1.3 ± 0.8) • 10-4 (1.2 ± 0.7) • 10-2


Sorption/ Desorption/ Suction Isotherms:

Table 3.7 (a) Results from Sorption/Desorption Measurements on six OSB products

RH, % Average Moisture Content, kg kg-1

Standard Deviation kg kg-1

48 (desorption) 0.051 0.003 50 (sorption) 0.050 0.017

69 (desorption) 0.105 0.007 69.3 (sorption) 0.086 0.012

88.9 (desorption) 0.142 0.005 91.5 (sorption) 0.163 0.008 93 (desorption) 0.205 0.030

Table 3.8 (b) Results from Pressure Plate Measurements on six OSB products

Suction Pa

Average Moisture Content, kg kg-1


1 x 106 0.58 0.09 3 x 105 0.71 0.10 1 x 105 0.88 0.12 3 x 104 1.06 0.11 1 x 104 1.11 0.12 4 x 103 1.15 0.11

0 1.50 0.14

Table 3.9. (a) Results from Sorption/Desorption Measurements on six Plywood products

RH, % Average Moisture Content, kg kg-1


49.9 (sorption) 0.060 0.015 48 (desorption) 0.062 0.003

69 (sorption) 0.095 0.006 70 (desorption) 0.108 0.008

90 (sorption) 0.160 0.006 91 (desorption) 0.187 0.010


Table 3.8 (b) Results from Pressure Plate Measurements on six Plywood products

Suction Pa

Average Moisture Content, kg kg-1


1 x 106 0.59 0.21 3 x 105 0.82 0.17 1 x 105 0.94 0.22 3 x 104 1.23 0.25

0 1.60 0.37

Note that zero suction corresponds to “vacuum saturation”. Some of the specimens swelled by as much as 30 %

by volume up on saturation.


4 Air Permeances and Water Vapour Permeances of Nine Types of Water Resistive Barriers

Background: The products investigated include paper based materials such as 10 minute, 30 minute, 60 minute and

# 15 felt and several polymer based products such as spun bonded polyolifines, polyacetates and perforated

polyethylene. For these products only the air permeances, water vapour transmission characteristics and

water absorption coefficients are measured.

Air Permeance:

Table 4.1. Air permeances of various Water Resistive Barriers

Material Thickness, mm Mass/area,

g/m-2

Air permeance

litre (75 Pa)-1 m-2 s-1

IA* 0.23 83 2.1 ± 1

II 0.20 199 0.49 ± 0.1

III 0.20 202 0.26 ± 0.15

IVA* 0.31 199 0.51 ± 0.09

VA* 0.64 521 0.15 ± 0.02

VC* 0.65 570 0.018 ± 0.004

VI 0.04 55 impermeable

VII 0.11 68 0.0033 ± 0.0008

VIII 0.15 81 4.3 ± 1.4

IX 0.12 95 0.62 ± 0.31

*IB, IVB and VB shown in Table 4.2, Table 4.3 and Table 4.4 are from IRC data bank; the measurements

were done in other projects.


The water absorption coefficients of paper based products (10 min, 30 min and 60 min) are all between 0.0005

and 0.001 kg m-2 s-½. Those of all polymeric products are below 0.0003 kg m-2 s-½.

Sum

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of V

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Res

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rrier

s (k

g m

-2 s

-1 P

a-1)

R

H,%

II

IIIII

IVIV

VV

VVI

VII

VIII

IX

AB

AB

AB

C

0

1.

06E-

09

9.30

E-10

2.87

E-09

2.37

E-09

1.

07E-

09

2.77

E-10

100

1.06

E-09

9.

30E-

102.

87E-

092.

37E-

09

1.07

E-09

2.

77E-

10

0

2.46

E-10

7.85

E-11

10

3.

18E-

108.

17E-

109.

34E-

112.

78E-

11

20

4.

11E-

109.

80E-

101.

13E-

102.

93E-

11

30

5.

32E-

101.

22E-

091.

39E-

103.

47E-

11

40

6.

93E-

101.

52E-

091.

76E-

104.

37E-

11

50

9.

07E-

101.

89E-

097.

10E-

102.

31E-

107.

10E-

115.

86E-

11

60

1.

19E-

092.

37E-

097.

80E-

103.

15E-

101.

00E-

108.

41E-

11

70

1.

59E-

092.

96E-

098.

50E-

104.

56E-

101.

60E-

101.

33E-

10

80

2.

14E-

093.

74E-

099.

20E-

107.

23E-

103.

00E-

102.

44E-

10

90

2.

95E-

094.

76E-

099.

80E-

101.

34E-

097.

20E-

106.

01E-

10

100

4.

17E-

096.

17E-

091.

00E-

093.

50E-

094.

70E-

094.

01E-

09

0

7.11

E-12

10

2.

37E-

11

20

3.

87E-

11

30

5.

49E-

11

40

7.

57E-

11

50

1.

07E-

10

60

1.

59E-

10

70

2.

61E-

10

80

4.

97E-

10

90

1.

23E-

09

91

1.

38E-

09

92

1.

56E-

09

93

1.

77E-

09

94

2.

03E-

09

95

2.

35E-

09

96

2.

76E-

09

97

3.

28E-

09

98

3.

98E-

09

99

4.

93E-

09

100

6.

32E-

09

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Wat

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(ng

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)

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-1

R

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IIIV

IVV

VV

VII

VIII

IX

BA

BB

IIIVI

AA

C

010

60.0

930.

028

70.0

2370

.0

1070

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7.0

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1060

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0.0

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70.0

10

70.0

277.

0

0

246.

078

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10

31

8.0

817.

0

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27.8

20

41

1.0

980.

0

11

3.0

29

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30

53

2.0

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13

9.0

34

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40

69

3.0

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17

6.0

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50

90

7.0

1890

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0.0

231.

071

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60

11

90.0

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0.0

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0.0

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15

90.0

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0.0

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0.0

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0

80

21

40.0

3740

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0.0

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030

0.0

244.

0

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29

50.0

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0.0

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0.0

601.

0

100

4170

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70.0

1000

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4700

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10.0

10

23

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20

38

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30

54

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40

75

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50

10

7.0

60

15

9.0

70

26

1.0

80

49

7.0

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12

30.0

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13

80.0

92

15

60.0

93

17

70.0

94

20

30.0

95

23

50.0

96

27

60.0

97

32

80.0

98

39

80.0

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49

30.0

100

6320

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7.1

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(per

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IVIV

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AB

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4.8

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5.6

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1.6

0.

5

20

7.2

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0.

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1.

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1.

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2.

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11

0.4


5 Hygrothermal Properties of Six Bricks Background:

As per the recommendation of Masonry Canada, three clay bricks, two concrete bricks

and one calcium silicate brick were included in Task 3, for material characterization. Masonry

Canada supplied all test samples.


The bulk densities of the bricks ranged between 1750 and 2300 kg m-3. The heat capacity

of brick, according to the IEA Annex 24 report is approximately 800 J K-1 kg-1.


Thermal conductivities, as measured on one specimen of each brick at two mean

temperatures are listed in Table 5.1. On the average, the temperature coefficient of thermal

conductivity for the bricks is ≈ 0.0007 W m-1 K-2.

Table 5.1. Thermal conductivities of the bricks at two mean temperatures

Thickness Density T(mean) Thermal Conductivity

Brick No. and Type

mm kg m-3 °C W m-1 K-1

12.0 2294 10.0 0.789 1. White Concrete Brick 12.0 2294 22.5 0.792 “” 12.4 1935 10.8 0.489 2. Red Matt Clay Brick 12.4 1935 24.1 0.500 “” 12.3 1719 9.82 0.425 3. Buff Matt Clay Brick 12.3 1719 24.2 0.434 “” 12.3 1821 9.82 0.509 4. Textured Coated Clay Brick 12.3 1821 23.4 0.522 “” 12.2 2315 11.2 0.728 5. Concrete Brick 12.2 2315 24.0 0.737 “” 12.2 1973 10.5 0.614 6. Calcium Silicate Brick 12.2 1973 23.6 0.623 “”


Water Vapour Permeability: The water vapour permeabilities (kg m-1 s-1 Pa-1) of the six bricks are listed in Table 5.2 and plotted in Figure 5.1.

Table 5.2. Water Vapour Permeabities of Brick

RH, % 1. Concrete 2. Clay 3. Clay 4. Clay 5. Concrete 6. Cal Sil 10 1.23E-12 1.51E-12 7.09E-12 3.04E-12 1.14E-12 1.14E-12 20 1.35E-12 1.57E-12 7.34E-12 3.15E-12 1.37E-12 1.74E-12 30 1.47E-12 1.64E-12 7.59E-12 3.26E-12 1.65E-12 2.65E-12 40 1.6E-12 1.7E-12 7.86E-12 3.37E-12 2E-12 4.06E-12 50 1.75E-12 1.77E-12 8.13E-12 3.48E-12 2.4E-12 6.25E-12 60 1.91E-12 1.84E-12 8.41E-12 3.6E-12 2.89E-12 9.72E-12 70 2.09E-12 1.91E-12 8.71E-12 3.73E-12 3.51E-12 1.54E-11 80 2.28E-12 1.99E-12 9.02E-12 3.86E-12 4.21E-12 2.5E-11 90 2.49E-12 2.07E-12 9.34E-12 3.99E-12 4.96E-12 4.26E-11 100 2.72E-12 2.15E-12 9.67E-12 4.13E-12 6.14E-12 7.97E-11

0.0E+00

1.0E-11

2.0E-11

3.0E-11

4.0E-11

5.0E-11

6.0E-11

7.0E-11

8.0E-11

9.0E-11

0 20 40 60 80 100

RH, %

Vapo

ur P

erm

eabi

lity,

kg

m-1

s-1

Pa-1

ConcreteClayClayClayConcreteCalSil

Figure 5.1. Water vapour permeabilities of six bricks.



The water absorption coefficients of the six bricks are given in Table 5.3.

Table 5.3: Water absorption coefficients for the six bricks.

No. 1 2 3 4 5 6 Type Concrete Clay Clay Clay Concrete Cal.Sil.

Absorption Coefficient kg m-2 s-½

0.0076 0.0268 0.0012 0.0322 0.0097 0.0181

Air Permeability: The measured air permeances for the bricks are found in Table 5.4.

Table 5.4. Air Permeance of Brick

Brick Type Specimen Thickness

mm

Air Permeance

l m-2 s-1(75 Pa) -1

Concrete 12.1 2.6 X 10-3

Clay 12.1 7.6 X 10-4

Clay 12.4 1.6 X 10-3

Clay 11.1 8.1 X 10-3

Concrete 14.7 3.5 X 10-4

Calcium Silicate 13.8 3.3 X 10-3


The results from sorption/desorption/suction measurements on the six bricks are shown in

Table 5.5. The equilibrium moisture content at each relative humidity is given as mass of moisture

per unit mass of the dry material. The results are plotted in Figure 5.2.


Table 5.5 Sorption/desorption/suction isotherms for the six bricks.

Moisture content, kg kg-1

RH, % Suction Pa

Concrete Clay Clay Clay Concrete Cal Sil

0 0.053 0.112 0.204 0.183 0.056 0.138 3 x 105 0.054 0.112 0.097 0.057 0.055 0.104 6.5 x 106 0.031 0.029 0.004 0.049 0.028 0.073

92 (sorption) 0.03 0.0007 0.0017 0.0016 0.0219 0.048 91 (desorption) 0.03 0.0012 0.0012 0.0007 0.0261 0.046

70 (sorption) 0.0244 0.0006 0 0.0006 0.0205 0.033 69 (desorption) 0.0259 0.0011 0.0013 0.0005 0.0206 0.031

50 (sorption) 0.021 0.001 0.0012 0.0011 0.0168 0.025 50 (desorption) 0.021 0.0006 0.002 0.0001 0.0147 0.0287

0

0.05

0.1

0.15

0.2

0.25

0 20 40 60 80 100RH, %

MO

ISTU

RE

CO

NTE

NT,

kg

kg-1

ConcreteClayClayClayConcreteCal Sil

Figure 5.2. Sorption/desorption/suction isotherms for the six bricks; the suction data from the pressure plate measurements are converted to relative humidity according to equation (4) on page 5.


Moisture Diffusivity: The moisture diffusivities of the six bricks are given in Table 5.6 and plotted in Figure 5.3.

These values are those calculated using the water absorption coefficient and saturation moisture

content for each product11.

Table 5.6. Moisture diffusivities (m2 s-1) of the six bricks.

Moisture Content kg m-3

Concrete Clay Clay Clay Concrete Cal Sil

50 3.57E-12 1.05E-12 2.22E-16 1.93E-13 3.54E-12 1.50E-13 60 1.16E-11 2.03E-12 3.34E-16 2.97E-13 1.07E-11 2.54E-13 70 3.80E-11 3.94E-12 5.02E-16 4.57E-13 3.26E-11 4.30E-13 80 1.24E-10 7.65E-12 7.56E-16 7.02E-13 9.89E-11 7.28E-13 90 4.05E-10 1.48E-11 1.14E-15 1.08E-12 3.00E-10 1.23E-12

100 1.32E-09 2.88E-11 1.71E-15 1.66E-12 9.10E-10 2.09E-12 110 4.31E-09 5.59E-11 2.58E-15 2.55E-12 2.76E-09 3.53E-12 120 1.41E-08 1.08E-10 3.88E-15 3.92E-12 8.37E-09 5.97E-12 140 4.08E-10 8.80E-15 9.25E-12 1.71E-11 160 1.53E-09 1.99E-14 2.19E-11 4.90E-11 180 5.78E-09 4.52E-14 5.17E-11 1.40E-10 200 2.17E-08 1.02E-13 1.22E-10 4.02E-10 230 3.49E-13 4.43E-10 1.95E-09 260 1.19E-12 1.61E-09 9.46E-09 290 4.06E-12 5.84E-09 320 1.38E-11 2.12E-08 350 4.72E-11

11 M. K. Kumaran. Moisture Diffusivity of Building Materials from Water Absorption Measurements. Journal of Thermal Envelope and Building Science, 22, p 349, 1999.


1.0E-16

1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-09

1.0E-08

1.0E-07

1.0E-0650 100 150 200 250 300 350

MOISTURE CONTENT, kg m-3D

IFFU

SIVI

TY, m

2 s-1 Concrete

ClayClayClayConcreteCal Sil

Figure 5.3. Moisture diffusivities of the six bricks.


6 Hygrothermal Properties of Mortar Mixes Used in North America

Background:

Two types of mortar, Type N and Type S, are commonly used across North America for

masonry veneer on wood frame construction. Each of these two mortar types has two "mix

formulations": one includes Portland cement and lime and the other Masonry cement. So four

mortar mixes are included in the testing programme for MEWS. These are listed in Table 6.1.

Table 6.1: Mortar mixes used for the determination of hygrothermal properties.

Mix Formulation Mortar Type Parts by Volume

Portland Cement Hydrated Lime Aggregate

Portland Cement-

Lime Mortar

S (Coded 1-S) 1 ½ 3½ to 4½

N (Coded 1-N) 1 1 4½ to 6

Masonry Cement

Type S

Masonry

Cement Type N

Aggregate

Masonry Cement

Mortar

S (Coded 2-S) 1 0 2¼ to 3

N (Coded 2-N) 0 1 2¼ to 3


The bulk densities, ρ, of the mortar mixes were in the range 1500 to 1800 kg m-3. The heat

capacity of mortar, according to the IEA Annex 24 report is approximately 900 J K-1 kg-1.


Thermal conductivities, measured on two specimens of each mix at two mean

temperatures are listed in Table 6.2.


Table 6.2. Thermal conductivities of four mortar mixes at two mean temperatures

Mortar

Type



1-S 19.6 1801 -0.35 0.503

‘’ 19.6 1801 23.0 0.527

‘’ 18.7 1729 -1.19 0.501

‘’ 18.7 1729 22.0 0.519

1-N 18.8 1778 -1.02 0.381

‘’ 18.8 1778 22.3 0.395

‘’ 19.1 1775 -1.32 0.465

‘’ 19.1 1775 20.5 0.482

2-S 19.1 1516 0.03 0.435

‘’ 19.1 1516 21.4 0.450

‘’ 18.6 1535 -0.77 0.429

‘’ 18.6 1535 21.7 0.446

2-N 18.7 1578 -1.01 0.448

‘’ 18.7 1578 22.1 0.460

‘’ 19.0 1609 -0.73 0.453

‘’ 19.0 1609 22.4 0.476

Water Vapour Permeability: The water vapour permeabilities (kg m-1 s-1 Pa-1) of the four mortar mixes are listed in Table 6.3 and plotted in Figure 6.1.

Table 6.3. Water Vapour Permeability of Mortar Mixes

RH, % 1-S 1-N 2-S 2-N

10 6.52E-12 7.72E-12 1.41E-11 1.34E-11 20 7.29E-12 8.64E-12 1.57E-11 1.48E-11 30 8.16E-12 9.68E-12 1.76E-11 1.64E-11 40 9.15E-12 1.09E-11 1.97E-11 1.82E-11 50 1.03E-11 1.22E-11 2.21E-11 2.02E-11 60 1.15E-11 1.37E-11 2.48E-11 2.24E-11 70 1.3E-11 1.55E-11 2.8E-11 2.5E-11 80 1.46E-11 1.74E-11 3.17E-11 2.79E-11 90 1.64E-11 1.97E-11 3.6E-11 3.12E-11

100 1.86E-11 2.23E-11 4.1E-11 3.5E-11


0

5E-12

1E-11

1.5E-11

2E-11

2.5E-11

3E-11

3.5E-11

4E-11

4.5E-11

0 20 40 60 80 100

RH, %

PER

MEA

BIL

ITY,

kg

m-1

s-1

Pa

-1

1-S1-N2-S2-N

Figure 6.1. Water vapour permeabilities of four mortar mixes.


The water absorption coefficients of the four mortar mixes are given in Table 6.4.

Table 6.4: Water absorption coefficients for the four mixes.

Absorption Coefficient

kg m-2 s-½ 1-S 1-N 2-S 2-N 0.063 0.086 0.011 0.016


Air Permeability:

Table 6.5. Measured air permeance for the mortar mixes.

Mortar Type Specimen Thickness

mm

Air Permeance

l m-2 s-1(75 Pa) -1

1-S 13.5 1.8 X 10-3

1-N 13.3 7.5 X 10-4

2-S 12.9 3.4 X 10-3

2-N 13.2 7.4 X 10-3


The results from sorption/desorption/suction measurements are shown in Table 6.6. The

equilibrium moisture content at each relative humidity is given as mass of moisture per unit mass

of the dry material. The results are plotted in Figure 6.2. For each mix there is a characteristic

"loop" showing the hysteresis due to sorption and desorption. The upper part of the loop is

desorption and the lower sorption.

Table 6.6. Sorption/desoption/suction isotherms for the four mixes.


RH, % Suction Pa

1-S 1-N 2-S 2-N

0 0.153 0.158 0.251 0.264 0 0.155 0.16 0.24 0.262 1 x 105 0.152 0.158 0.241 0.254 3 x 105 0.149 0.157 0.217 0.205

90 (desorption) 0.071 0.077 0.069 0.061 70 (desorption) 0.06 0.061 0.054 0.044 50 (desorption) 0.045 0.047 0.039 0.034

50 (sorption) 0.026 0.019 0.005 0.004 70 (sorption) 0.051 0.04 0.026 0.023 90 (sorption) 0.066 0.063 0.065 0.053


0

0.05

0.1

0.15

0.2

0.25

0.3

0 20 40 60 80 100

RELATIVE HUMIDITY, %

MO

ISTU

RE

CO

NTE

NT

kg k

g-11-S 1-N2-S2-N1-S 1-N2-S2-N

Figure 6.2. Sorption/desorption/suction isotherms for the four mortar mixes; the suction data from the pressure plate measurements are converted to relative humidity according to equation (4) on page 5.

Moisture Diffusivity: The moisture diffusivities of the four mixes are given in Table 6.7 and plotted in Figure 6.3.

These values are those calculated using the water absorption coefficient and saturation moisture

content for each mix.

Table 6.7. Moisture diffusivities (m2 s-1) of the four mortar mixes.


1-S 1-N 2-S 2-N

170 1.09E-09 1.37E-09 1.24E-12 1.16E-12 180 1.85E-09 2.28E-09 1.80E-12 1.63E-12 190 3.15E-09 3.81E-09 2.62E-12 2.30E-12 200 5.35E-09 6.35E-09 3.82E-12 3.23E-12 210 9.09E-09 1.06E-08 5.57E-12 4.54E-12 220 1.54E-08 1.76E-08 8.12E-12 6.39E-12 230 2.62E-08 2.94E-08 1.18E-11 8.98E-12 240 4.46E-08 4.90E-08 1.73E-11 1.26E-11 250 7.58E-08 8.18E-08 2.51E-11 1.78E-11 260 1.29E-07 1.36E-07 3.66E-11 2.50E-11 280 7.78E-11 4.94E-11 300 1.65E-10 9.76E-11 320 3.51E-10 1.93E-10 340 7.46E-10 3.82E-10 360 1.58E-09 7.54E-10 380 3.37E-09 1.49E-09 400 2.95E-09


1.0E-11

1.0E-10

1.0E-09

1.0E-08

1.0E-07150 200 250 300 350 400 450

MOISTURE CONTENT, kg m-3

DIF

FUSI

VITY

, m2 s

-1

1-S1-N2-S2-N

Figure 6.3. Moisture diffusivities of the four mortar mixes.


7 Hygrothermal Properties of Three Types of Stuccos Used in North America

Background:

Three types of stucco are investigated as recommended by Task Group 2. They are:

Regular Lime Stucco (Coded in this report as 471-1)

Regular Portland Stucco and (Coded in this report as 471-26)

Acrylic Stucco (Coded in this report as 471-51)


The bulk densities, ρ, of the stucco samples ranged between 1760 and 1960 kg m-3. The

heat capacity of stucco, according to the IEA Annex 24 report is approximately 840 J K-1 kg-1.


Thermal conductivities, measured on two specimens of each type of stucco at two mean temperatures are listed in Table 7.1.

Table 7.1. Thermal conductivities of stucco at two mean temperatures

Code Thickness Density T(mean) Thermal Conductivity


471-1 14.3 1776 0.37 0.348 ‘’ 14.3 1776 22.4 0.366 ‘’ 12.7 1762 0.30 0.320 ‘’ 12.7 1762 20.3 0.338

471-26 14.7 1956 0.24 0.389 ‘’ 14.7 1956 22.5 0.406 ‘’ 12.9 1955 0.20 0.390 ‘’ 12.9 1955 22.3 0.409

471-51 11.9 1800 0.44 0.345 ‘’ 11.9 1800 22.2 0.363 ‘’ 13.8 1790 0.13 0.376 ‘’ 13.8 1790 22.6 0.400


Water Vapour Permeability: The water vapour permeabilities (kg m-1 s-1 Pa-1) of the three stuccos are listed in Table 7.2 and plotted in Figure 7.1.

Table 7.2. Water Vapour Permeabilities of Three Stuccos

RH, % 471-1 471-26 471-51 10 6.7E-13 5.85E-13 2.4E-12 20 1.34E-12 8.85E-13 2.55E-12 30 2.01E-12 1.19E-12 2.72E-12 40 2.68E-12 1.49E-12 2.9E-12 50 3.35E-12 1.8E-12 3.09E-12 60 4.02E-12 2.1E-12 3.29E-12 70 4.69E-12 2.41E-12 3.5E-12 80 5.36E-12 2.72E-12 3.73E-12 90 6.03E-12 3.03E-12 3.97E-12

100 6.7E-12 3.34E-12 4.23E-12

0

2E-12

4E-12

6E-12

8E-12

1E-11

1.2E-11

1.4E-11

0 20 40 60 80 100

RH, %

PER

MEA

BIL

ITY,

kg

m-1

s-1

Pa

-1

471-1471-26471-51Van LowVan High

Figure 7.1. Water vapour permeabilities of three stuccos are compared with those from the field; the Van-low and Van High give the range shown by samples from Vancouver buildings.



The water absorption coefficients of the three stuccos are given in Table 7.3.

Table 7.3. Water absorption coefficients for the three stucco.

Absorption Coefficient

kg m-2 s-½ 471-1 471-26 471-51 0.0050 0.0123 0.0074

Air Permeability: The measured air permeances for the stuccos are given in Table 7.4.

Table 7.4. Air Permeance for the three stuccos

Stucco Code Specimen Thickness

mm

Air Permeance

l m-2 s-1(75 Pa) -1

471-1 13.0 2.4 X 10-5

471-26 13.6 3.6 X 10-5

471-51 10.4 1.8 X 10-4


The results from sorption/desorption/suction measurements are shown in Table 7.5. The

equilibrium moisture content at each relative humidity is given as mass of moisture per unit mass

of the dry material. The results are plotted in Figure 7.2. The upper part of the loop is desorption

and the lower sorption.


Table 7.5. Sorption/desorption/suction isotherms for the three stuccos.


RH, % Suction, Pa 471-1 471-26 471-51 0 0.16 0.12 0.157 0 0.149 0.11 0.149 1 x 105 0.1571 0.117 0.157

90 (desorption) 0.084 0.07 0.069 70 (desorption) 0.062 0.052 0.051 50 (desorption) 0.05 0.042 0.043

50 (sorption) 0.04 0.03 0.016 70 (sorption) 0.052 0.037 0.041

0.074 0.058 0.054

Figure 7.2. Sorption/desorption/suction isotherms for the three stuccos; the suction data from the pressure plate measurements are converted to relative humidity according to equation (4) on page 5.

90 (sorption)

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0 20 40 60 80 100


MO

ISTU

RE

CO

NTE

NT,

kg

kg-1

471-1471-26471-51471-1471-26471-51



The moisture diffusivities of the three products are given in Table 7.6 and plotted in Figure

7.3. These values are those calculated using the water absorption coefficient and saturation

moisture content for each mix.

Table 7.6. Moisture diffusivities (m2 s-1) of the three stuccos.


471-1 471-26 471-51

9.55E-15 1.41E-13 2.13E-14 60 1.58E-14 2.6E-13 3.53E-14 70 2.63E-14 4.8E-13 5.87E-14 80 4.36E-14 8.85E-13 9.75E-14 90 7.22E-14 1.63E-12 1.62E-13

100 1.2E-13 3.01E-12 2.69E-13 120 3.29E-13 1.02E-11 7.43E-13 140 9.06E-13 3.48E-11 2.05E-12 160 2.49E-12 1.18E-10 5.66E-12 180 6.85E-12 4.01E-10 1.56E-11 200 1.88E-11 1.36E-09 4.31E-11 220 5.18E-11 4.64E-09 1.19E-10 240 1.42E-10 1.58E-08 3.28E-10 260 3.92E-10 9.06E-10 280 1.08E-09 2.5E-09 320 1.38E-11 350 4.72E-11

50


1.0E-15

1.0E-14

1.0E-13

1.0E-12

1.0E-11

1.0E-10

1.0E-09

1.0E-08

1.0E-070 50 100 150 200 250 300

MOISTURE CONTENT, kg m-3

DIF

FUSI

VITY

, m2 s

-1

471-1471-26471-51

Figure 7.3. Moisture diffusivities of the three stuccos.


8 Hygrothermal Properties of Eight Fiberboard Sheathing Products

General description of the products:

Two of the products investigated were plain fiberboard (no coating or facer) and four

were coated with a thin layer of black material on both major surfaces. One product had a paper

facer on one major surface while another one had an aluminum foil facer. The nominal thickness

of the products varied between 11 mm and 13 mm. The densities varied between 235 kg m-3 and

330 kg m-3.

Thermal Conductivity:

The results from the thermal conductivity measurements on the eight products are listed

in Table 8.1. Measurements were done in duplicate and at two mean specimen temperature.

Table 8.1. Thermal conductivities of eight fiberboard products.

Type


mm kg m-3

°C

W m-1 K-1

Paper Facer 12.54 284.2 24.1 0.0497 ‘’ -0.1 0.0466 ‘’ 12.53 284.6 24.1 0.0497 ‘’ -0.2 0.0467

Plain 11.68 264.1 24.1 0.0508 ‘’ 0.1 0.0476 ‘’ 11.7 264.8 24.1 0.0509 ‘’ 0 0.0479

Foil Facer 12.27 256.9 23.1 0.0465 ‘’ -0.5 0.0438 ‘’ 12.25 257.3 23 0.047 ‘’ -0.6 0.0443

Plain 12.75 237.1 23.1 0.0459 ‘’ -0.5 0.0436 ‘’ 12.77 238.4 23.1 0.0461 ‘’ -0.5 0.0437

Black Coat 10.52 267.8 24 0.0472 ‘’ -0.3 0.0448

Black Coat 10.58 268.7 24 0.0472


‘’ -0.5 0.0449 Black Coat 11.92 283.8 24.1 0.0495

‘’ -0.3 0.0467 ‘’ 11.88 277.9 24.1 0.0489 ‘’ -0.3 0.04616

Black Coat 11.97 325.8 24.1 0.0534 ‘’ 0 0.0507 ‘’ 11.96 328.1 24 0.0534 ‘’ 0 0.0508

Black Coat 12.44 320.5 24 0.0532 ‘’ 0.1 0.0498 ‘’ 12.4 329.5 24.1 0.0539 ‘’ 0 0.0506

0.04

0.042

0.044

0.046

0.048

0.05

0.052

0.054

0.056

200 250 300 350

Density, kg m-3

Ther

mal

Con

duct

ivity

, W m

-1 K

-1

Figure 8.1. Dependence of thermal conductivity (at approximately 24 °C) of fiberboard specimens on density.

The above dependence of thermal conductivity (λ, W m-1 K-1) on density (ρ, kg m-3), at

24 °C can be approximated by:

λ = 0.0260 + 8.4 X 10-5 ρ


From Figure 8.2, the temperature dependence of thermal conductivity, (dλ/dT) is

approximately 1.2 X 10-4 W m-1 K-2.

0.04

0.042

0.044

0.046

0.048

0.05

0.052

0.054

0.056

-10 0 10 20 30

Mean Temperature, °C

Ther

mal

Con

duct

ivity

, W m

-1 K

-1

Series1

Figure 8.2. Dependence of thermal conductivity of fiberboard specimens on temperature.


Water Vapour Permeabilities:

The results from the water vapour transmission rate measurements on seven of the eight

products were analyzed to derive the values for their water vapour permeabilities. These derived

values are listed in Table 8.2 and plotted in Figure 8.3. The water vapour permeances of all

products are listed in Table 8.3 and compared in Figure 8.4. The product with the aluminum foil

facer showed high resistance to water vapour transmission across it. The measured vapour

transmission rates are 1/1000 of corresponding rates measured on natural fiberboard.

0.0E+00

5.0E-12

1.0E-11

1.5E-11

2.0E-11

2.5E-11

3.0E-11

3.5E-11

4.0E-11

4.5E-11

0 20 40 60 80 100

RH, %

PER

MEA

BIL

ITY,

kg

m-1

s-1

Pa-1

Paper FacerPlainPlainBlack CoatBlack CoatBlack CoatBlack Coat

Figure 8.3. Dependence on relative humidity of water vapour permeabilities of the fiberboard products.


0.0E+00

5.0E-10

1.0E-09

1.5E-09

2.0E-09

2.5E-09

3.0E-09

3.5E-09

4.0E-09

0 20 40 60 80 100


PER

MEA

NC

E, k

g m

-2 s

-1 P

a-1

Paper FacerPlainPlainBlack CoatBlack CoatBlack CoatBlack Coat

Figure 8.4. Water vapour permeances of seven fiberboard products.

Sum

mar

y R

epor

t fro

m T

ask

3 of

MEW

S

53

Hyg

roth

erm

al P

rope

rties

of S

ever

al B

uild

ing

Mat

eria

ls

Tabl

e 8.

2. W

ater

Vap

our P

erm

eabi

litie

s (k

g m

-1 s

-1 P

a-1) o

f Fib

erbo

ard

Prod

ucts

RH

, %

Pape

r Fac

er

Plai

n Pl

ain

Blac

k C

oat

Blac

k C

oat

Blac

k C

oat

Blac

k C

oat

01.

15E-

123.

05E-

113.

64E-

112.

30E-

112.

64E-

111.

65E-

111.

88E-

11

101.

29E-

123.

14E-

113.

70E-

112.

33E-

112.

64E-

111.

70E-

111.

92E-

11

201.

45E-

123.

23E-

113.

75E-

112.

36E-

112.

64E-

111.

75E-

111.

96E-

11

301.

63E-

123.

32E-

113.

81E-

112.

40E-

112.

64E-

111.

80E-

112.

00E-

11

401.

84E-

123.

42E-

113.

87E-

112.

43E-

112.

64E-

111.

85E-

112.

04E-

11

502.

07E-

123.

52E-

113.

93E-

112.

46E-

112.

64E-

111.

90E-

112.

08E-

11

602.

33E-

123.

63E-

113.

99E-

112.

50E-

112.

64E-

111.

96E-

112.

12E-

11

702.

63E-

123.

74E-

114.

05E-

112.

53E-

112.

64E-

112.

02E-

112.

16E-

11

802.

96E-

123.

85E-

114.

11E-

112.

57E-

112.

64E-

112.

08E-

112.

21E-

11

903.

34E-

123.

97E-

114.

17E-

112.

61E-

112.

64E-

112.

14E-

112.

25E-

11

100

3.77

E-12

4.09

E-11

4.24

E-11

2.64

E-11

2.64

E-11

2.20

E-11

2.30

E-11

Sum

mar

y R

epor

t fro

m T

ask

3 of

MEW

S

54

Hyg

roth

erm

al P

rope

rties

of S

ever

al B

uild

ing

Mat

eria

ls

Tabl

e 8.

3. W

ater

Vap

our P

erm

eanc

es (k

g m

-2 s

-1 P

a-1) o

f Fib

erbo

ard

Prod

ucts

RH

, %

Pape

r Fac

er

Plai

n Pl

ain

Blac

k C

oat

Blac

k C

oat

Blac

k C

oat

Blac

k C

oat

09.

10E-

112.

58E-

092.

78E-

092.

11E-

092.

18E-

091.

37E-

091.

51E-

09

101.

02E-

102.

66E-

092.

82E-

092.

14E-

092.

18E-

091.

41E-

091.

54E-

09

201.

15E-

102.

74E-

092.

87E-

092.

17E-

092.

18E-

091.

45E-

091.

57E-

09

301.

30E-

102.

82E-

092.

91E-

092.

20E-

092.

18E-

091.

49E-

091.

60E-

09

401.

46E-

102.

90E-

092.

95E-

092.

23E-

092.

18E-

091.

53E-

091.

63E-

09

501.

64E-

102.

99E-

093.

00E-

092.

26E-

092.

18E-

091.

57E-

091.

66E-

09

601.

85E-

103.

07E-

093.

04E-

092.

29E-

092.

18E-

091.

62E-

091.

70E-

09

702.

09E-

103.

17E-

093.

09E-

092.

32E-

092.

18E-

091.

67E-

091.

73E-

09

802.

35E-

103.

26E-

093.

14E-

092.

36E-

092.

18E-

091.

72E-

091.

77E-

09

902.

65E-

103.

37E-

093.

19E-

092.

39E-

092.

18E-

091.

77E-

091.

80E-

09

100

2.99

E-10

3.47

E-09

3.24

E-09

2.43

E-09

2.18

E-09

1.82

E-09

1.84

E-09


Water Absorption Coefficients:

The results from the water absorption rate measurements across the major surfaces on

the eight products were analyzed to derive values for water absorption coefficients. These

derived values are listed in Table 8.4.

Table 8.4. Water Absorption Coefficients (kg m-2 s-½) of Fiberboard Products

Aluminum Foil Faced 0.00042Black Coat 0.00096Black Coat 0.0012Black Coat 0.0012Black Coat 0.0015Paper Faced 0.0019Plain 0.0021Plain 0.0054

Air Permeance/ Permeability:

The results from the airflow rate measurements on the eight products are listed in Table

8.5

Table 8.5. Airflow characteristics of eight fiberboard products; measurements are done in triplicate and the reported values are the averages.

Description Density Thickness Air Permeability Air Permeance

No. (kg/m3) (mm) (l·(75 Pa)-1·m-1·s-1) (l·(75 Pa)-1·m-2·s-1)

1 Paper facer 288.4 12.69 (1.6 ± 0.7) • 10-4 (1.2 ± 0.6) • 10-2

2 Plain 264.6 11.51 (2.20 ± 0.02) • 10-2 (1.91 ± 0.01)

3 Aluminum facer 254.6 12.51 impermeable impermeable

4 Plain 243.4 13.05 (2.06 ± 0.05) • 10-2 (1.58 ± 0.04)

5 Black Coat 270.3 10.73 (1.46 ± 0.06) • 10-2 (1.36 ± 0.05)

6 Black Coat 282.9 12.50 (1.26 ± 0.05) • 10-2 (1.04 ± 0.4)

7 Black Coat 326.4 12.00 (1.46 ± 0.02) • 10-2 (1.22 ± 0.02

8 Black Coat 328.7 12.65 (1.41 ± 0.03) • 10-2 (1.11 ± 0.01)


Sorption/ Desorption/Suction Isotherms

The equilibrium moisture contents of seven fibreboard products (kg/ kg dry material) at various

relative humidity levels are listed in Table 8.6. The product with aluminum foil was not included in

the measurements due to anticipated long duration for equilibration.

Table 8.6. Equilibrium moisture contents of seven fibreboard products

RH, % Suction

Pa

Plain Paper

Facer

Plain Black

Coat

Black

Coat

Black

Coat

Black

Coat

0 3.841 4.263 4.398 4.697 3.639 2.929 3.092

0 3.885 4.322 4.495 4.083 3.736 3.051 3.113

3 x 105 0.303 0.388 0.409 0.440 0.432 0.564 0.468

91 (s) 0.160 0.193 0.193 0.174 0.183 0.137 0.146

69 (s) 0.061 0.103 0.109 0.101 0.104 0.072 0.079

50 (s) 0.029 0.075 0.082 0.075 0.077 0.046 0.051

50 (ds) 0.049 0.055 0.057 0.052 0.052 0.041 0.044

69.5 (ds) 0.090 0.091 0.096 0.086 0.087 0.071 0.076

91 (ds) 0.187 0.178 0.183 0.164 0.163 0.146 0.147

(s) sorption and (ds) desorption)


Moisture diffusivities derived from moisture uptake (along the edges) experiments on six

of the eight products are listed below in Table 8.7. Measurements on the other two did not yield

analyzable results.

Table 8.7. Moisture Diffusivity of Six Fibreboard Products

Plain Paper Facer Plain Black Coat Black Coat Black Coat

Moisture Content Diffusivity Diffusivity Diffusivity Diffusivity Diffusivity Diffusivity

kg m-3 m2 s-1 m2 s-1 m2 s-1 m2 s-1 m2 s-1 m2 s-1

30 1.71E-09 2.33E-09 1.14E-08 9.76E-09 3.03E-08 4.56E-08 40 4.92E-10 1.69E-09 4.44E-09 5.71E-09 1.86E-08 9.94E-09 50 3.20E-10 1.44E-09 2.54E-09 2.29E-09 1.18E-08 5.38E-09 60 2.53E-10 1.41E-09 1.77E-09 1.26E-09 7.88E-09 3.55E-09 70 2.17E-10 1.61E-09 1.36E-09 7.55E-10 5.48E-09 2.57E-09 80 1.95E-10 2.46E-09 1.11E-09 4.90E-10 3.96E-09 1.96E-09 90 1.81E-10 6.70E-09 9.45E-10 3.40E-10 2.95E-09 1.54E-09 100 1.70E-10 2.32E-09 8.22E-10 2.25E-09 1.24E-09 110 1.63E-10 1.33E-09 7.28E-10 1.76E-09


120 1.57E-10 8.91E-10 6.55E-10 1.40E-09 130 1.53E-10 6.42E-10 5.96E-10 1.13E-09 140 1.50E-10 4.78E-10 5.46E-10 9.31E-10 150 1.48E-10 3.58E-10 5.05E-10 7.63E-10 160 1.46E-10 4.70E-10 6.26E-10

1.45E-10 4.40E-10 180 190 1.44E-10 3.90E-10 200

1.44E-10 1.45E-10

230

1.54E-10

350 1.75E-10 2.08E-10

2.86E-10

530 3.10E-10

3.86E-10

170 1.44E-10 4.13E-10

1.44E-10 3.69E-10

210 3.51E-10 220 3.34E-10

1.46E-10 3.19E-10 240 1.47E-10 3.05E-10 250 1.49E-10 2.93E-10 260 1.50E-10 2.81E-10 270 1.52E-10 2.70E-10 280 2.60E-10 290 1.56E-10 2.51E-10 300 1.59E-10 2.43E-10 310 1.62E-10 2.35E-10 320 1.65E-10 2.27E-10 330 1.68E-10 2.21E-10 340 1.71E-10 2.14E-10

360 1.79E-10 2.02E-10 370 1.83E-10 1.96E-10 380 1.88E-10 1.91E-10 390 1.92E-10 1.86E-10 400 1.98E-10 1.82E-10 410 2.03E-10 420 2.09E-10 430 2.16E-10 440 2.22E-10 450 2.30E-10 460 2.38E-10 470 2.46E-10 480 2.55E-10 490 2.65E-10 500 2.75E-10 510 520 2.98E-10

540 3.24E-10 550 3.38E-10 560 3.53E-10 570 3.69E-10 580


The substrates of three of the products investigated were compressed fiberboard, of the

fourth one OSB and of the fifth one plywood. All had vinyl coatings on one major surface. The

thickness of the products varied between 10.5 mm and 15.1 mm. The densities varied between

580 kg m

9 Hygrothermal Properties of Five Siding Products General description of the products:

-3 and 930 kg m-3.

Thermal Conductivity:

The results from the thermal conductivity measurements on the five products are listed in

Table 9.1. Measurements were done in duplicate and at two mean specimen temperature.

Table 9.1. Thermal conductivities of five siding products.

Siding Substrate Thickness Density T(mean) Thermal Conductivity

No

mm

0.2 24

0.3

23.5

kg m-3

°C W m-1 K-1

1 OSB 12.84 705.3 24.5 0.133 ‘’ -0.1 0.0935 ‘’ 12.9 687.9 24 0.104 ‘’ 0.4 0.0989 2 Plywood 14.91 607.8 23.8 0.104 ‘’ 0.0997 ‘’ 14.75 585.9 0.105 ‘’ 0.1 0.0933 3 Fibreboard 12.17 778.8 24.1 0.0968 ‘’ 0.0928 ‘’ 12.18 780.3 24 0.103 ‘’ 0.2 0.0986 4 Fibreboard 12.09 889.2 23.8 0.119 ‘’ 0.1 0.11 ‘’ 11.98 911.1 23.8 0.121 ‘’ 0.1 0.113 5 Fibreboard 10.43 738.7 0.0937 ‘’ -0.7 0.0896 ‘’ 10.65 716.8 23.5 0.0944 ‘’ -0.8 0.0899


0.08

0.09

0.1

0.11

0.12

0.13

0.14

550 650 750 850 950

Density, kg m-3

Ther

mal

Con

duct

ivity

, W m

-1 K

-1

Figure 9.1. Dependence of thermal conductivity (at approximately 24 °C) of siding specimens on density.

Figure 9.1 shows that no general correlation between thermal conductivity and density

can be made. At 24 °C, the thermal conductivity is approximately equal to 0.1 W m-1 K-1 for all

products.

From Figure 9.2, the temperature dependence of thermal conductivity, (dλ/dT) is

approximately 4.0 X 10-4 W m-1 K-2.


0.08

0.09

0.1

0.11

0.12

0.13

0.14

-5 0 5 10 15 20 25 30

Mean Temperature, °C

Ther

mal

Con

duct

ivity

, W m

-1 K

-1

Figure 9.2. Dependence of thermal conductivity of siding specimens on temperature.

Water Absorption Coefficients:

The results from the water absorption measurements (the coated surface in contact with

water) on the five products are listed in Table 9.2.

Table 9.2. Water Absorption Coefficients (kg m-2 s-½) of Siding Products

Siding No. 1 0.000382 0.000473 0.00058

0.000600.00062

4 5


Air Permeance/ Permeability:

The results from the airflow rate measurements on the five products are listed in Table

.3. 9

Density Air Permeability Air Permeance

Table 9.3. Airflow characteristics of five Siding Products; measurements are done in triplicate and the reported values are the averages

Thickness

No. (kg/m3) (mm) (l·(75 Pa)-1·m-2·s(l·(75 Pa)-1·m-1·s-1) -1)

1 692.5 12.37 (1.3 ± 0.5) • 10-5 (1.1 ± 0.4) • 10-3

2 633.6 15.08 impermeable impermeable

3 819.0 12.05 (1.4 ± 0.8) • 10-5 (1.1 ± 0.7) • 10-3

4 928.5 12.17 (1.8 ± 0.5) • 10-6 (1.5 ± 0.4) • 10-4

5 805.1 10.60 (2.8 ± 0.8) • 10-4 (2.7 ± 0.7) • 10-2


Sorption/ Desorption/Suction isotherms

The equilibrium moisture contents of the five products (kg/ kg dry material) at various relative

humidity levels are listed below in Table 9.4.

Table 9.4 Equilibrium moisture content of five siding products

RH, % Suction, Pa 1 2 3 4 5

0 1.151 1.004 0.828 0.643 0.898

0 0.994 0.867 1.091 0.679 0.924

3 x 105 0.654 0.629 0.381 0.365 0.376

91 (desorption) 0.178 0.173 0.160 0.154 0.134

69 (desorptrion) 0.098 0.098 0.091 0.092 0.076

50 (desorption) 0.059 0.058 0.056 0.058 0.043

50 (sorption) 0.048 0.051 0.048 0.051 0.046

70 (sorption) 0.079 0.081 0.071 0.072 0.069

91 (sorption) 0.157 0.163 0.131 0.120 0.131

Water Vapour Permeance:

Water vapour permeances (kg m-2 s-1 Pa-1) of the five products are listed in Table 9.5 and plotted

in Figure 9.3.

Table 9.5. Water Vapour Permeances of five siding products

RH, % 1 2 3 4 5

10 8.67E-12 4.22E-12 1.79E-10 4.16E-11 3.68E-10 20 8.67E-12 4.22E-12 2.08E-10 4.16E-11 3.84E-10 30 1.73E-11 1.24E-11 2.42E-10 7.62E-11 4.02E-10 40 2.82E-11 2.66E-11 2.81E-10 1.17E-10 4.2E-10

4.13E-11 4.81E-11 3.27E-10 1.64E-10 4.39E-10 60 5.65E-11 7.83E-11 3.8E-10 2.16E-10 4.58E-10 70 7.35E-11 1.18E-10 4.43E-10 2.74E-10 4.79E-10 80 9.25E-11 1.7E-10 5.17E-10 3.36E-10 5.01E-10

1.13E-10 2.33E-10 6.04E-10 4.03E-10 5.24E-10 100 1.36E-10 3.11E-10 7.07E-10 4.75E-10 5.48E-10

50

90


0.00E+00

1.00E-10

2.00E-10

3.00E-10

4.00E-10

5.00E-10

6.00E-10

7.00E-10

8.00E-10

0 20 40 60 80 100 120

RH, %

Perm

eanc

e, k

g m

-2 s

-1 P

a-1

12345

Figure 9.3. Water vapour permeances of the five siding products.



Moisture diffusivities derived from moisture uptake (along the edges) experiments on

three of the five products are listed below in Table 9.6. Measurements on the other two did not

yield analyzable results.

Table 9.6. Moisture diffusivity of three siding products

Siding 2 Siding 4 Siding 5 Moisture

Content

6.20E-11

4.47E-11 4.36E-11

1.60E-09 4.26E-11

150 1.30E-09 4.07E-11 160 1.19E-09 4.03E-11 170 1.09E-09

1.18E-09 3.86E-11

3.87E-11

8.62E-10

7.30E-10 6.78E-10 3.96E-11

370 380

4.14E-10

Diffusivity Diffusivity Diffusivity

kg m-3 m2 s-1 m2 s-1 m2 s-1

30 1.44E-08 2.85E-09 1.10E-10 40 8.23E-09 7.54E-10 7.48E-11 50 4.69E-09 4.32E-10 60 2.84E-09 3.02E-10 5.53E-11 70 1.97E-09 2.32E-10 5.11E-11 80 1.66E-09 1.88E-10 4.83E-11 90 1.59E-09 1.58E-10 4.63E-11 100 1.61E-09 1.36E-10 110 1.63E-09 1.19E-10 120 1.06E-10 130 1.52E-09 9.56E-11 4.18E-11 140 1.42E-09 4.12E-11

3.99E-11 180 1.03E-09 3.96E-11 190 1.01E-09 3.93E-11 200 1.01E-09 3.91E-11 210 1.04E-09 3.90E-11 220 1.08E-09 3.88E-11 230 1.12E-09 3.87E-11 240 1.16E-09 3.87E-11 250 260 1.18E-09 3.86E-11 270 1.17E-09 280 1.13E-09 3.87E-11 290 1.08E-09 3.88E-11 300 1.01E-09 3.89E-11 310 9.36E-10 3.90E-11 320 3.92E-11 330 7.92E-10 3.92E-11 340 3.94E-11 350 360 6.34E-10 3.98E-11

5.96E-10 4.01E-11 5.59E-10 4.04E-11

390 5.19E-10 4.08E-11 400 4.71E-10 4.12E-11 410 4.16E-11


420 3.47E-10

4.21E-11 430 2.75E-10 4.27E-11 440 2.08E-10 4.33E-11 450 1.57E-10 4.40E-11 460 1.36E-10 4.48E-11 470 1.52E-10 4.57E-11 480 2.04E-10 4.68E-11 490 2.63E-10 4.80E-11 500 2.61E-10 4.95E-11


10 Hygrothermal Properties of EIFS Base Coat + Finish Coat

Background: Five EIFS wall specimens were built for large-scale testing in Task 6 of MEWS. All specimens

used polymer cement as the base coat and “Latex Acrylic with Integral Colour and Texture” as

the finish coat. These two materials were not available as thick slabs for detailed measurements

of all properties. Furthermore, from an earlier project at IRC it was evident that the polymeric

materials showed very slow responses to the processes used in various hygrothermal property

measurements.

Large test samples of (finish coat + base coat + EPS) were removed from the wall specimen # 7,

after the completion of the large-scale tests. Several spot checks were done on the above

composite and from the well known properties of EPS, the hygrothermal properties for the finish

coat and base coat were derived as input to hygIRC. The spot checks included water absorption,

water vapour transmission and saturation measurements. Product information from several

manufacturers, as provided by IRC’s evaluation officers, were also used as guidelines to finalize

the input for hygIRC. The derived properties are listed below in Table 10.1.

Table 10.1. Derived Properties of EIFS base coat and finish coat

RH, %

Equilibrium Moisture

Content

kg kg-1 Air Permeability

Vapour Permeability

kg m-1 s-1 Pa-1

Moisture

Diffusivity

m2 s-1

3.50E-12 1.00E-16

20 0.013 3.50E-12 1.00E-16

30 0.015 3.50E-12 1.00E-16

40 0.017 3.50E-12 1.00E-16

50 0.019 3.50E-12 1.00E-16

3.50E-12 1.00E-16

1.00E-16

90 0.043 3.50E-12 1.00E-16

6.86E-12

3.50E-12 9.91E-12

97 0.066 3.50E-12 1.27E-11

98 0.072 1.47E-11 3.50E-12

99 0.081 3.50E-12 1.54E-11

100 0.090 3.50E-12 1.61E-11

10 0.011

60 0.022 Impermeable

70 0.026 3.50E-12

80 0.032 3.50E-12 1.00E-16

95 0.057 3.50E-12

96 0.060


11 Hygrothermal Properties of Exterior Grade Gypsum Board

Background: The product investigated had a yellow and a white fibrous facers on either side of the board. The

bulk density was approximately 700 kg m-3 and the total thickness approximately 13 mm. Each of

the two facers was approximately 0.7 mm thick. The properties of interior gypsum board being

well-known, only spot checks were made on the properties, to establish the fundamental

difference between the two types of gypsum boards. The results from various tests are listed

below.

Water vapour permeance:

Thermal conductivity:

The thermal conductivity measured at 0 °C and at 24 °C showed no temperature dependence.

The measured value is 0.15 W m-1 K-1. (Similar to interior gypsum board)

The average water vapour permeance measured at a mean RH of 80 % on three test specimens

was 4.43E-09 kg m-2 s-1 Pa-1. (Similar to interior gypsum board)

Water absorption Coefficients:

Across the facers ≈ 0.001 kg m-2 s-½

Along the edge ≈ 0.006 kg m-2 s-½

Liquid water movement is much slower in this product when compared with interior gypsum

board.

Air permeance:

The air permeance is (1.9 ± 0.4) x 10-2 l m-2 s-1 (75 Pa)-1. (Similar to interior gypsum board)


12 Water Vapour Permeability of a Spray Polyurethane Foam Insulation Product

2

Background:

A foam product was applied on a 4' x 4' plywood substrate at a nominal thickness of

2.25". The thickness was achieved in three passes of the spray. The sample was submitted for

testing in July 1998. The bulk density of the foam product is 39.7 kg m-3. The core as measured

on 11 May 1999 and at a sample thickness of 47.1 mm showed a thermal conductivity of 0.0227

W m-1 K-1.

Water vapour permeability:

From the data on water vapour transmission measurements the water vapour permeability was

derived and is shown below in Table 1 .1.

Table 12.1. Water vapour permeability of Spray Polyurethane foam

RH, % Permeability kg m-1 s-1 Pa-1

50 2.86E-12 3.00E-12

70 3.15E-12 3.31E-12

90 3.48E-12 3.65E-12

60

80

100

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