Waterproofing Installation Inspection

Per CAN/CGSB-37.2 and CAN/CGSB-37.50, waterproofing substrates must be sound, clean, dry, and free of sharp projections, form release agents, and curing compounds. Concrete substrates must be cured a minimum of 28 days with moisture content below 5% by mass. Surface defects (honeycombing, voids, cracks) must be repaired before membrane application. Surface profile must be suitable for the specified membrane system.

1. Verify concrete substrate has been cured a minimum of 28 days and measure moisture content using a calibrated moisture metre (below 5% by mass)

2. Check that all surface defects including honeycombing, voids, and cracks wider than 1 mm are repaired with compatible patching material

3. Confirm substrate surface is clean and free of form release agents, curing compounds, oils, and loose material

4. Verify sharp projections, fins, and form tie ends are ground flush with the surface

5. Check that required primers are applied to the substrate per the waterproofing manufacturer's requirements

- Concrete substrate moisture too high causing membrane blistering and adhesion failure

- Honeycombing and voids in concrete not repaired before membrane application allowing water paths behind membrane

- Form release agents or curing compounds not removed preventing membrane adhesion

- Substrate cracks not addressed before membrane application leading to membrane rupture from crack movement

Per NBC 9.13.2 and CAN/CGSB-37.50, below-grade foundation walls and slabs exposed to hydrostatic pressure must be waterproofed with a membrane system rated for below-grade applications. Self-adhered rubberized asphalt membranes, hot-applied rubberized asphalt, and bentonite sheets are common systems. Membranes must be fully adhered, lapped per manufacturer's requirements, and protected from damage during backfill.

1. Verify waterproofing membrane type is suitable for below-grade application and conforms to CAN/CGSB-37.50 or CAN/CGSB-37.2

2. Confirm membrane is fully adhered to the primed substrate with no wrinkles, bridging, or fish-mouths

3. Check that all laps and seams meet minimum overlap requirements (typically 75-100 mm) and are fully sealed

4. Verify membrane extends from the footing to a minimum of 150 mm above finished grade per NBC 9.13.2

5. Confirm protection board or drainage mat is installed over the membrane before backfill to prevent damage

- Membrane not fully adhered to substrate due to cold temperature application below manufacturer's minimum

- Laps and seams not properly sealed creating paths for water infiltration under hydrostatic pressure

- Membrane damaged during backfill from sharp aggregate or construction debris without protection board

- Membrane not extended above grade allowing water entry at the grade line

Per NBC 9.14, foundation drainage must be provided to relieve hydrostatic pressure against below-grade walls. Weeping tiles (perforated drain pipe) must be installed at the footing level, surrounded by clear granular filter material, and connected to a sump pit, storm sewer, or daylight outlet. Drainage mats or dimpled membranes on the foundation wall direct water to the weeping tile system.

1. Verify weeping tile is installed at the footing level with perforations facing down, sloped a minimum of 1:200 toward the discharge point

2. Confirm weeping tile is surrounded by a minimum of 150 mm of clear granular drainage material wrapped in filter fabric per NBC 9.14.3

3. Check that a drainage mat or dimpled membrane is installed on the foundation wall extending from below grade to the weeping tile

4. Verify weeping tile is connected to a sump pit with a functioning pump, or to the storm sewer or daylight outlet

5. Confirm backfill in the upper zone is free-draining granular material or that a drainage layer is provided to direct surface water away

- Weeping tile not sloped adequately or crushed during backfill preventing drainage

- Filter fabric omitted allowing fine soil particles to clog the weeping tile over time

- Drainage mat not connected to the weeping tile creating a gap in the drainage path

- Sump pump not connected or tested before occupancy

Per NBC Part 5 and CAN/CGSB-37.50, plaza decks and podium slabs over occupied space require a robust waterproofing membrane system that resists hydrostatic pressure and accommodates structural movement. Hot-applied rubberized asphalt or multi-ply modified bitumen systems are typical. Protection layers, drainage boards, and overburden must be specified. Flood testing is required before installation of overburden.

1. Verify waterproofing membrane system is the correct type and number of plies per specifications and CAN/CGSB-37.50

2. Confirm membrane is applied to the specified dry film thickness and is fully adhered to the primed substrate

3. Check that all details (drains, walls, columns, expansion joints) are properly detailed with additional membrane reinforcement

4. Verify flood test is conducted at a minimum depth of 50 mm for a minimum of 48 hours with no leakage detected in the space below

5. Confirm protection board, drainage layer, and filter fabric are installed over the membrane before overburden placement

- Membrane punctured during placement of protection layers or overburden

- Drain details not properly tied into the waterproofing membrane allowing leaks at drain connections

- Expansion joint waterproofing detail failing due to excessive structural movement

- Flood test not performed before overburden making leak detection and repair extremely costly

Per NBC 9.25 and TCNA Handbook, interior wet areas (bathrooms, kitchens, laundry rooms, mechanical rooms) require waterproofing membranes to prevent moisture damage to the building structure. Shower enclosures, tub surrounds, and steam rooms must have waterproof membranes meeting ANSI A118.10. Floor waterproofing must be turned up at walls a minimum of 150 mm and integrate with floor drains.

1. Verify waterproofing membrane is installed in all designated wet areas and is the correct product per specifications (ANSI A118.10 compliant)

2. Confirm membrane is turned up at all walls to the required height (full height in showers, minimum 150 mm elsewhere)

3. Check that floor drain connections are properly clamped to the waterproofing membrane with no gaps

4. Verify all corners, changes in plane, and penetrations are reinforced with membrane fabric and additional coats

5. Confirm flood test of shower pans and wet area floors is completed for a minimum of 24 hours with no leakage

- Waterproofing membrane not extended to full height in shower areas allowing moisture behind tiles

- Floor drain not properly integrated with the membrane creating a leak path at the drain connection

- Membrane applied too thin in corners and at changes in plane where cracking is most likely

- Flood test not performed allowing leaks to go undetected until damage to lower levels occurs

Per NBC 5.6.1 and NBC 9.27, exterior wall assemblies must prevent rain penetration through a combination of cladding, air space, and a water-resistive barrier (WRB). The WRB must be lapped shingle-fashion to shed water and must be integrated with window and door flashings per NBC 9.27.3. Weep holes and through-wall flashings in masonry walls must be provided per CSA A371 at all shelf angles, lintels, and base of wall.

1. Verify the water-resistive barrier is installed shingle-fashion with upper courses overlapping lower courses by a minimum of 100 mm

2. Confirm WRB is properly integrated with window and door head, sill, and jamb flashings per NBC 9.27.3

3. Check that through-wall flashings are installed at all shelf angles, lintels, and base of masonry veneer per CSA A371

4. Verify weep holes are open and properly spaced (typically every 800 mm) at the base of wall and above all through-wall flashings

5. Confirm a minimum 25 mm air space is maintained between the cladding and the WRB for drainage and drying

- WRB not integrated with window flashings creating water entry points at window-to-wall interfaces

- Through-wall flashings missing at shelf angles allowing water to bypass the drainage plane

- Weep holes blocked by mortar droppings preventing drainage of the wall cavity

- Air space behind cladding bridged by mortar or insulation preventing drainage and drying

Per NBC Part 5 and CAN/CGSB-19.13, sealant joints must be designed to accommodate anticipated movement and must maintain a watertight seal at all transitions, penetrations, and control joints. Sealant must be compatible with adjacent materials and applied to properly prepared surfaces with backer rod per CAN/CGSB-19.13. Joint dimensions must provide the correct width-to-depth ratio (typically 2:1) for the sealant type.

1. Verify sealant type is compatible with adjacent materials and meets CAN/CGSB-19.13 performance requirements for the application

2. Confirm joint dimensions provide the correct width-to-depth ratio (typically 2:1 for polyurethane sealants) with backer rod installed

3. Check that substrate surfaces are clean, dry, and primed (where required by manufacturer) before sealant application

4. Verify sealant tooling produces a concave profile with good adhesion to both sides of the joint

5. Confirm sealant joints are provided at all required locations: control joints, perimeter of openings, material changes, and expansion joints

- Sealant applied without backer rod resulting in three-sided adhesion and premature failure

- Joint width too narrow to accommodate building movement causing cohesive or adhesive sealant failure

- Sealant applied to contaminated or wet surfaces preventing proper adhesion

- Missing sealant joints at critical transitions allowing water infiltration into the building envelope