Basement

2.      Provision of proper drainage and pumping system to avoid delay in concreting operation leading to unplanned cold joints.

3.      Dimension for service opening, tolerance for plumb alignment and any deviation should not exceed the prescribed value.

4.      Formwork, props and bracing should be free from debris. No gap between joints to prevent leakage, adequate support to prevent bulging / displacement.

5.      Properly fitted joints else later those cannot be sealed properly.

2.      Anchorage, lap length and cover as per specification.

3.      Rebar secured in place and free from dirt and rust.

4.      Special attention required for working on ground slab around pile caps.

2.      Aggregate properly graded, free of dirt and excess moisture.

3.      Rebar free from dirt, rust, scale.

2.      Vibrated for good compaction.

3.      Proper curing for 28 days.

4.      No curing agent should be used for a surface to receive water proofing

2.      Alignment, plumb and level within tolerance level.

3.      Clean, smooth and even surface. Any visual exposure of course aggregates; cracks or uneven surface should be finished smooth before applying waterproofing

4.      Compressive strength checked by concrete cube test.

5.      Rebar location and covers checked by Electro-cover meter test.

6.      Uniformity tested by ultrasonic pulse velocity.

Cleanliness: dirt, loose unsound material, formwork release agent (oil, wax, grease, silicone etc.) prevent proper bonding. These should be cleaned thoroughly with chemical, water or mechanical means.

Dryness: moisture content should not exceed 6% to prevent blistering.

Shelf life of the material should not be expired during application.

Material either should be freshly prepared or taken from a sealed container.

Manufacturer’s instruction to be followed to select tools and method of application to ensure final dry film thickness (DFT) and /or proper adhesion.

Curing time should be strictly maintained. Protective boards placed on under-cured single component LAM may form depression and blistering.

Sealing of the edges by self-adhesive mastic on all sides at days’ end.

Thickness check: For LAM, dry film thickness (DFT) with wet-mil gauge so that an additional coat can be applied to rectify below gauge film thickness. For single ply, cut along seam and seam probes are tested.

Checking adhesion by pull off test.

Checking of lapping length (for preformed membrane).

Water tightness test: ponding with 25mm of water and maintaining the same for specified periods of time (2 to 24 hours as per frequency of wetting and drying condition).

Provision of protection board /layer to prevent puncture and abrasion from sharp construction tools, struts, props. Else dust and dirt from excavation work in the vicinity stuck to new or freshly applied waterproofing.

Use of proper backfilling material free from rock, boulder, organic matter.

Placing and compaction of backfilling in small lifts (12” appx.) as per soil type. Else settlement of backfill may cause slippage of prefab membrane.

Water proofing should have protection from soil (for slab on ground), construction and backfilling activities.

Good planning of work is required. Installed waterproofing remains exposed for long due to delay in backfilling, which is not desirable.

·       Sufficient gap to be maintained between two water stops or with Rebar for proper compaction of the concrete.

·       Immediately followed by concreting operation. Else to be discarded.

2.      Cement should be fresh. Sand free from contaminant and excess moisture.

3.      Use of a workable mortar of specific mix. Re-tempering is allowed as per instruction by adding a small amount of water.

2.      Height for a day’s work should not cross the prescribed limit. Else bulging, buckling, over-stressing of lower joints take place.

3.      The cavity should be kept clean from all discarded mortar or debris to avoid moisture bridging in later stage.

2.      Curing is required for development of bond strength.

3.      Fall in cavity drain should be maintained and checked for leakage or blockage

.

• Various pointing (L to R): flashed struck, keyed & recessed

1.      Mix should be cohesive to avoid bleeding.

2.      Mix should not stiffen or dry out to an extent that prevents full compaction.

3.      Level to be achieved by using laser level and staff.

4.      Finishing operation should start after the bleeding stops. Floating followed by trowelling at least twice ensures higher abrasion resistance and compaction, but more trowelling may lead to a polished or slippery floor.

5.      The surface should not be closed by power floating too soon, as this might otherwise entrap water from late bleeding. Similarly, trowelling should be timed to prevent an excess of laitance.

6.      After compaction and finishing, the surface should not be allowed to dry out quickly and should be cured continuously for at least 7 days

1.      Application of dry shake at appropriate time to a suitably designed concrete Availability of sufficient free water at the surface enables the finish to be made fully wet and worked monolithically into the concrete.

1.      Weigh batching and thorough mixing for uniform mix.

2.      The screed should be laid while the base concrete is still plastic but not when bleed water is still present.

2.      Joint should be in proper straight line to avoid differential contraction.

3.      Sawn joints may be sealed initially with a flexible sealant to accommodate shrinkage movement

2.      Adhesion to the base of a separate bonded wearing screed;

3.      Slip resistance.

4.      Abrasion resistance.

• Adequate curing of substrate to avoid shrinkage cracks. Else it sucks water from plaster or water based paints.
• Moisture content should not exceed 6%.
• Cleaning to remove sand, dirt, dust or loose unsound particles.
• Prolonged storing, inadequate stirring, use of incompatible solvent/ thinner or mixing with leftover paints from previous batches should be avoided.

• Use of clean tools and proper method as per manufacturer’s instruction.
• The fittings on walls should have received a primer or antirust coat.

• Screed (if applicable) is properly cured, rendered and kept clean.
• Careful cutting and handling of tile.
• Soaking of tiles to saturated surface dry condition before laying.
• The back is kept contaminant-free and proper key provided.

• Should not be laid over cracks.
• Joints should be properly filled
• Tiles should be properly tapped in places on an even screed.
• Surface should be wiped off after tiling.

• Tiles should not be subjected to any loading / vibration unless set.
• Removal of dirt, dust, plasters or paint dropping from subsequent activities.
• Proper scheduling of work. Else excessive vibration, direct impact from other construction activity makes the tile to crack.