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A Diagnostic Checklist for Damage Evaluation in Concrete BalconiesThis checklist can help assess specific observations and problems as preparation for conducting a condition survey and developing a repair strategy in consultation with a design professional.

Worksheet

A. Rust stains or spots

PROBABLE CAUSES: Corrosion of reinforcing steel/embedded metal, Chloride contamination, Galvanic reaction,Carbonation of concrete, Atmospheric contaminants,Moisture penetrating the slab, Ponding water

__ Probable source?

Number and location of balconies/walkways affected per elevation?__North elevation __East elevation__South elevation __West elevation

Areas affected:__Slab edges__Top of slab__Underside of slab (overhead)__Near railing pockets__Near/under door frames__Tranistions (column/wall; slab/wall)__In PT, near anchor pockets

B. Efflorescence (Calcium carbonate exhibited as white crust/flaking)

PROBABLE CAUSE: Moisture moving through the slab.

Number and location of balconiesand/or walkways affected per elevation: __North elevation __East elevation__South elevation __West elevation

Areas affected:__Slab edges__Top of slab__Underside of slab (overheads)__Through-slab cracking__Near railing pockets/c.i.p. railings__Near/under door/window frames/tracks__Construction joints__Transitions (column/wall; slab/wall)__In PT, near anchor pockets

Designing and executing a long-term effective repair strategy for concrete balconies (and walkways or eyebrows) startswith a thorough investigation and analysis of the nature and cause of the problem. A good condition survey will includethree main components: an analysis of the structural plans, a visual inspection, and field and laboratory testing.

1. Identify the type of balcony and/or walkway construction.

2. Conduct a visual survey of the structure and list the location and extent of damage and indicators of potential damage.Documenting observed conditions/problems with photographs is recommended.

A. Structural type of balconies (B) and/or walkways (W)__ Cast-in-place cantilevered concrete slab (flat plate)

Balcony slab is monolithic with floor deck? Yes or No

__ Post-tensioned cast-in-place cantilevered concrete slab (flat plate)Balcony slab is monolithic with floor deck? Yes or No

__ Beam and slab (cast-in-place) Bond beam? Yes or No

__ Precast T-beam and slab__ Precast plank with topping__ Metal pan deck with topping

Steel support framing? Yes or NoConcrete beam supports? Yes or No

B. Number of balconies (B) and/or walkways (W)?______Design type:__ Parapet__ Kneewall w/ railing

Upturned or downturned beam?__ Slab with railing__ Railing type and installation (if applicable)

Type metal?_______________________________________Installation:__ Cast in__ Rail pocket/grout pocket__ Surface mount/shoe mount

C. Is a copy of the plans available? Yes or No

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Worksheet

H. Weatherproofing and waterproofing problems*PROBABLE CAUSES: Inadequate/improper slope, Unevenness of surface, Sag or settling, Sealant failure, Waterproofing membrane failure

Ponding Water? Yes or NoIntrusion of water into interior? Yes or No

Number and location of balconies and/or walkways affected per elevation: __North elevation __East elevation__South elevation __West elevation

Areas affected:__Top of slab__At thresholds__Transitions (column/wall; slab/wall)__Joint seals__Penetrations/conduits__Drains__Scuppers__Drip edges__Flashing__Other________________________________

I. Corrosion of metalPROBABLE CAUSE: Moisture intrusion (through cracks, porosity, etc.), Chloride contamination, Dissimilar metals,Galvanic reaction

__Metal railing posts__Grout pockets__Cast-in-place__Surface mount

__Metal door/window tracks/frames

__Pipe column supports__Reinforcing steel__Spalled?__Inadequate original cover?__In PT, broken/exposed casings/strands?

__Other fittings__Drains__Conduits__Scuppers__Flashing__Drip edges

Number and location of balconies and/or walkways affected per elevation: __North elevation __East elevation__South elevation __West elevation

J. Inadequate cover over concretePROBABLE CAUSE: Poor construction practice

Number and location of balconies and/or walkways affected per elevation: __North elevation __East elevation__South elevation __West elevation

How observed?__Exposed reinforcing steel

__Other___________________________________

K. Moisture Traps__Failed existing waterproofing membrane/vapor

barrier coatings__Carpet on balconies__Consistently wet?__Mildew?

__Tiled balconies__Delaminated? Yes or No__Cracked? Yes or No__Mildew in grout lines?

__Pebble stone deck covering__Paint/vinyl coverings__Landscaping, planters, pots__Other____________________________________________

Number and location of balconies and/or walkways affected per elevation: __North elevation __East elevation__South elevation __West elevation

L. Popouts or voidsPROBABLE CAUSE: Poor construction practice

How severe?_________________________________

Number and location of balconies and/or walkways affected per elevation: __North elevation __East elevation__South elevation __West elevation

*For a Diagnostic Checklist for waterproofing problems, please see issue 1/97 of restoration direct.

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M. Deterioration/failure of previous repairsWhen were previous repairs performed?_____________Type of failed repair____________________________Number and location of balconies and/or walkways affected per elevation: __North elevation __East elevation__South elevation __West elevation

N. Aesthetic problemsPROBABLE CAUSES: Weathering/aging, Owners’ perceptions

__Discoloration__Staining__Lack of modern railings__Outdated color__Screens/enclosures__Hurricane windows

3. Identify any hindrances to adequate visual survey and testing.

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. Summarize findings of visual survey as background for designing field and laboratory testing.

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

5. Designing a repair strategyDeveloping an appropriate repair strategy can ensuredurable, long-term balcony restorations. Using this checklist to help identify and analyze specific problems as preparation for consulting a professional specialzing in concrete restoration can be an important first step indeveloping the best repair strategy and selecting themost appropriate repair technniques and materials foryour balcony restorations.

Test Methods for Observed ConditionsPart of a thorough investigation involves conducting a condition survey. The design professional, as part of her/her analysis, maychoose to use several test methods to help determine the cause andextent of the damage observed. Listed below are a variety of observedconditions and some of the test methods used. Test methods aretypically classified as either destructive or nondestructive.

OBSERVED CONDITION TEST METHODS

Delamination, spalling Hammer soundingChain dragMechanical delamination

detectorsImpact echoUltrasonic pulse velocityInfrared thermography

Cracks Hammer soundingCrack gauges to measure width,

depthImpact echoInfrared thermographyCalibrated crack monitors

(moving cracks)Structural movement monitorsUltrasonic pulse velocityRadiographyPetrographic analysisAnalysis of core samples for

tensile, flexural strength

Corrosion PachometerDelamination detectorsHalf cell potentials/electrical

potential measuring equipmentRate of corrosion probes

Chloride contamination Chloride titrationAnalysis of dust/core samples

for chloride levels

Carbonation Phenolphthalein test for pHInfrared spectroscopyPetrographic analysis

Inadequate cover/location Pachometerof reinforcing steel Rebar locators

Loss of concrete strength/ Swiss hammerDefective concrete Impact echo

Probe penetration (Windsor probe)Core sample analysis (Compressive strength, Tensile strength, Flexural strength, Petrographic analysis)

Pull out tests for existing concreteUltrasonic pulse velocity