TOPIC:Fire resistance, separating and fire- division walls,

fire escapes.

Walls, resistance to weather and damp.

Fire resistance and fire

escapesFire safety within a building is an extremely important issue. At the very least you should ensure that there is an adequate means of escape in case of fire, all measures and protective means will be in vain if there is no personal responsibility.

A fire escape is a special kind of emergency exit, usually mounted to the outside of a building or occasionally inside but separate from the main areas of the building. It provides a method of escape in the event of a fire or other emergency that makes the stairwells inside a building inaccessible. Fire escapes are most often found on multiple-story residential buildings, such as apartment buildings.

Common-style fire escapes

in Soho, New York City.

According to the occupation safety and health

Act 2006

“All means of escape from fire shall be properly

maintained and kept free from obstruction.

The contents of any room in which a person is

employed shall be arranged or disposed to provide

free passage way for the persons employed in the

work place shall not be locked or fastened in such

a manner that it cannot be easily and immediately

opened from inside.

In case of any workplace constructed or converted

for use as a workplace after the commencement of

this act, all doors which afford means of exit from

any building of the workplace for the persons

employed in it, shall, except in the case of sliding

doors, be constructed to open outwards.

Every window, door, or other exit which afford

means of escape in case of fire or giving access to

it, other than the means of exit in ordinary use,

shall be distinctively and conspicuously marked by

a notice printed in red letters of any adequate size.

In every workplace to which this act applies,

effective steps shall be taken to ensure that all the

persons employed are familiar within the means of

escape in case of fire, and with the routine to be

followed in case of fire.”

According to the Act "Section 704.5:

The fire resistance rate of the exterior walls with the fire

separation distance is greater than 1524mm shall be

rated for exposure to fire from outside. The fire

resistance rate of exterior walls with fire separation

distance (1524mm) or less shall be rated to exposure to

fire from both sides.”

You must carry out a Fire Risk Assessment .The overall

aim of a fire risk assessment is to reduce the risk of fire,

the risk of fire spread, and ensure that people can escape.

A fire risk assessment should systematically identify all fire

related hazards within the premises and analyze how

those hazards may adversely affect the building and its

occupants. It should identify the level of risk that those

hazards may present and also identify suitable control

measures for any significant findings. It is often best done

by a fire safety professional.

According to the Act “Section 705.2

Structural stability: Fire walls shall have structural

stability under fire conditions to allow collapse of

construction on either side without collapse of the

wall for the duration of time indicated by the

required fire resistance rating.”

Place signs detailing actions to be taken in the event

of a fire, make sure your residents and visitors know

how to react and where their nearest fire assembly

point is located, making sure that all residents are

able to understand any instruction provided.

According to the occupation safety

and health Act 2006

“In all workplaces subject to this act,

there shall be provided and

maintained, to be readily accessible,

means of extinguishing fire, which

shall be adequate and suitable

having regard to the circumstances

of each case.”

Goals and objectives of fire

resistance:There are generally four goals: life safety, property

protection, mission continuity and environmental

protection.

Life safety goals relate to protection of the building

occupants, and members of the public in the event

a fire occurs in the building. Life safety would

almost certainly be a goal in any very tall building.

Firefighter and first responder safety also need to

be considered.

Property protection relates to minimizing damage

to the building and building contents from fire.

Additionally, limiting damage to exposed buildings

would fit into this category.

Mission continuity goals address the impact on the

building and its tenants from fire. Some building

codes do not address mission continuity in very tall

buildings, although mission continuity might be

addressed for tenants who perform vital roles in the

community, such as hospitals and public safety

buildings. In most cases, the building owners,

tenants or their insurers will provide mission

continuity goals.

Environmental protection goals consider the

permissible impact on the environment from fire or

fire protection. Environmental protection goals

might address limitations on the types of fire

protection agents that can be used in a building

and the environmental consequences of a fire in a

facility which might release toxic products into the

atmosphere, ground water or bodies of water.

According to the occupation

safety and health Act 2006

“All stocks of highly

inflammable substances shall

be kept in a fire-resistant store

or in a safe place outside any

occupied buildings.

The store shall not be situated

in a way that endangers the

means of escape from the

workplace or from any part of

the workplace by persons

employed in it, in the event of

fire occurring in any part of the

workplace.”

Fire prevention and control services

include the following:

Sprinkler systems

Drenchers

Hydrants

Gas extinguishers

Fire alarms

Smoke, fire and heat

detectors

Electrical alarm

circuits

Pressurization of

escape routes

Walls, Resistance to Weather

and damp.Both the bricks and the mortar are porous. They will

absorb a considerable amount of water both from the

rain, and rising from damp ground by capillary action.

Modern brickwork relies on a damp-proof course to

prevent rising damp, and a drained cavity to resist

rain penetration. It is assumed that the whole of the

outer leaf will become damp in wet weather

conditions, and may have water running down both

faces in the case of wind-driven rain. Flashings and

built-in items are detailed to allow for this condition.

The damp-proof course is located

below the lowest timber or floor

(to keep these items dry), close to

the ground, but high enough that it

will not be breached by any proposed

or subsequent landscaping work.

Building codes specify suitable

materials for damp-proof courses,

which usually include bitumen-coated

copper and zinc, lead, and suitable

plastics.

The material must be flexible enough

to be racked up in the joints where the ground

level changes, and to remain intact across small cracks.

According to the Act in Physical Planning Act,

2010

“Every wall, floor and roof shall be constructed so

as to prevent any harmful effect on the building or

the health of the occupants caused by the passage

of moisture to any part of the building from— (a)

the ground; and (b) the weather.”

Filling the cavity below ground

When a brick wall extends below the ground floor, the

cavity is filled with mortar to ground level, struck off

with an outward slope. The damp-proof course is

located above the mortar controlling the use of land

generally.

This flashing, and the water

proofing under the slab, serve

as a damp-proof course to

prevent rising damp. However,

a layer of damp-proof material

may be used under the full

thickness of the inside leaf to

break bond, to avoid stresses

when the concrete shrinks and the brickwork expands.

Maintaining the cavity

Because the cavity is an essential part of the

weatherproofing system, the detailing must allow for

maintaining its integrity. A minimum cavity of 40-50

mm is considered essential to allow mortar droppings

to be observed and removed from ties and flashings.

If insulation is to be built into the cavity, it should be a

rigid board to avoid sagging, and held firmly against

the inner skin to maintain the minimum cavity width.

Flashings at floor level

Whenever a floor beam or slab crosses the cavity,

such as when both leaves of a non-load bearing wall

are supported at each floor level, a flashing and

weep holes are needed in essentially the same

configuration as a wall supported on a ground floor

slab.

Head and sill flashing

When it is necessary to close the cavity at door and window openings, the head and sill must be flashed (unless the head is so close under an overhang that it will not get wet). The head flashing extends far enough beyond the opening to throw any water clear of the jambs.

Limiting water absorption into

wallsWind-driven rain will penetrate a vertical face, which

will become damp and then dry out fairly uniformly

when the rain stops. Horizontal surfaces such as

parapets and sills absorb more water, and this tends

to penetrate into the wall below and dry out unevenly,

leaving unsightly wet patches for several days.

Therefore copings and flashings have to be designed

not merely to prevent water from entering the

building, but to shed the water from these areas to

limit the amount of absorption.

A coping like that shown in the diagram should have

drip grooves under each edge, to force water to drip

clear of the wall. If the material is waterproof (precast

concrete, or a metal sheet formed to a similar profile)

a dpm should not be required underneath it; but a

dpm is needed under a brick or stone coping

because it is porous.

Rising Dampness

Dampness within dwellings can take many forms.

True Rising Dampness is caused by a failure or lack

of an effective damp-proof course (DPC). Sometimes

a perfectly adequate damp-proof course is bridged by

high ground levels or blocked cavities resulting in a

similar pattern. Symptoms are generally damage to

decoration, breakdown of plasterwork and damage to

skirting boards and other joinery timbers. However, it

is possible for a property to be suffering from Rising

Dampness without some or any of these symptoms.

The minimum thickness and maximum height of

parapet walls should be as indicated in the diagram

above.

If the criteria indicated below cannot be attained

design calculations should be submitted to indicate

suitability.

Note, the information guidance on the left relates

only to structural aspects of parapet wall design.

Further advice should be obtained with regard to

moisture penetration.

Differences in level of ground or other solid construction between one side of the wall and the other should be less than 4 times the thickness of the walls.

References

1918 News article about an elastic canvas fire escape chute -- Keep a Fire-Escape Under the Window-Sill, Popular Sciencemonthly, December 1918, page 47, Scanned by Google Books: http://books.google.com/books?id=EikDAAAAMBAJ&pg=PA47

Biography for Abraham Wivell

"Fire Victims Slide Safely Down Tubular Chute" Popular Mechanics, February 1930

"Air Conditioner Installation". New York City Department of Buildings. Retrieved 30 June 2014.