Waterproofing Installation Inspection

Per ASTM D4258 (Standard Practice for Surface Cleaning of Concrete for Coating), all concrete surfaces receiving waterproofing must be clean, sound, and free of contaminants. ASTM D4259 (Standard Practice for Abrading Concrete) covers mechanical surface profiling. Concrete must be cured per ACI 308R (Guide to External Curing of Concrete) to a minimum 28-day strength before membrane application. Surface moisture content must not exceed manufacturer limits, typically below 5% per ASTM D4263 (Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method).

1. Verify concrete has reached minimum 28-day cure per ACI 308R before waterproofing application

2. Perform ASTM D4263 plastic sheet test — tape a 18" x 18" polyethylene sheet to surface for 16 hours and check for condensation

3. Use a moisture meter to confirm surface moisture is below manufacturer threshold (typically under 5%)

4. Check that surface is free of laitance, curing compounds, form-release agents, and efflorescence per ASTM D4258

5. Verify surface profile meets membrane manufacturer requirements — typically CSP 2-3 per ICRI 310.2R for liquid-applied systems

6. Inspect for cracks, honeycombing, and voids — all must be repaired and patched before membrane application

- Waterproofing applied to concrete that has not reached full 28-day cure

- Excessive surface moisture causing membrane adhesion failure

- Laitance or curing compound residue left on substrate preventing bond

- Inadequate surface profile resulting in poor mechanical adhesion

- Unrepaired cracks or voids telegraphing through membrane

Per IRC R406.1, concrete and masonry foundation walls that retain earth and enclose habitable or usable space below grade must be waterproofed. IRC R406.2 requires waterproofing to extend from the top of the footing to the finished grade. Liquid-applied membranes must meet ASTM D6083 (Standard Specification for Liquid Applied Acrylic Coating Used in Roofing) or ASTM C836 (Standard Specification for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane). Sheet membranes must meet ASTM D4068 (Standard Specification for Chlorinated Polyethylene (CPE) Sheeting for Concealed Water-Containment Membrane). Dampproofing alone per IRC R406.1 is only permitted for non-habitable spaces.

1. Confirm waterproofing (not just dampproofing) is specified for all habitable below-grade spaces per IRC R406.2

2. Verify membrane extends from top of footing to finished grade level without gaps

3. Use a mil gauge to check liquid-applied membrane thickness — minimum 60 mils wet (40 mils dry) typical for ASTM D6083 systems

4. Inspect sheet membrane laps — minimum 2-4 inch overlap per manufacturer specs with proper adhesive or heat welding

5. Check all penetrations (pipes, conduits, tie holes) are sealed with compatible sealant and detail membrane

6. Verify protection board or drainage mat is installed over membrane before backfill to prevent damage

- Dampproofing used where waterproofing is required for habitable basement space

- Insufficient membrane thickness on liquid-applied systems failing to meet ASTM D6083 minimums

- Membrane not carried to top of footing, leaving a gap at the footing-wall joint

- No protection board installed, causing membrane puncture during backfill

- Incompatible sealants used at penetrations causing membrane degradation

Per IBC Section 1402.2 and IRC R703.1, a weather-resistive barrier (WRB) is required behind all exterior wall coverings. The WRB must be applied shingle-fashion with upper layers overlapping lower layers per IRC R703.2. Window and door openings must be flashed per ASTM E2112 (Standard Practice for Installation of Exterior Windows, Doors and Skylights). Building paper must meet ASTM D226 Type I (asphalt-saturated felt) or housewrap must meet ICC-ES AC38 criteria for water resistance, air resistance, and vapor permeability.

1. Verify WRB is installed shingle-fashion with horizontal laps of minimum 2 inches and vertical laps of minimum 6 inches per IRC R703.2

2. Confirm WRB is properly integrated with window and door flashing per ASTM E2112 — sill pan flashing installed first, then jamb, then head

3. Check that WRB is continuous behind all penetrations (vents, pipes, electrical boxes) with proper sealing

4. Verify WRB extends to within 1 inch of the bottom of sheathing or is properly terminated at the foundation transition

5. Inspect all fastener penetrations — WRB must be self-sealing around fasteners or taped per manufacturer instructions

- WRB installed with reverse laps (lower layer over upper), directing water behind the barrier

- Missing or improperly sequenced window flashing not conforming to ASTM E2112 pan-flashing method

- Tears or gaps in WRB left unrepaired before cladding installation

- WRB not properly integrated at roof-to-wall intersections

- Non-compliant housewrap product that does not meet ICC-ES AC38 performance criteria

Per the TCNA Handbook (Tile Council of North America), shower receptors and wet area floors must be waterproofed with a membrane meeting ANSI A118.10 (Standard Specification for Load Bearing, Bonded, Waterproof Membranes for Thin-Set Ceramic Tile and Dimension Stone Installation) or ANSI A118.12 (Standard Specification for Crack Isolation Membranes for Thin-Set Ceramic Tile and Dimension Stone Installations). The IPC (International Plumbing Code) Section 417.5.2 requires shower pan liners to be tested watertight by filling to the threshold for 24 hours. Membrane must extend a minimum of 3 inches above the finished threshold per IPC 417.5.2.

1. Verify waterproof membrane is installed on all shower walls and floor — membrane must meet ANSI A118.10 for bonded applications

2. Confirm membrane turns up shower walls to a minimum height of 72 inches above the drain per TCNA Handbook Method B421

3. Check shower pan liner extends minimum 3 inches above finished threshold height per IPC 417.5.2

4. Perform flood test — fill shower pan to threshold level and hold for minimum 24 hours per IPC 417.5.2, inspect for leaks from below

5. Verify all membrane seams and corners are reinforced with manufacturer-specified fabric or tape

6. Inspect curb waterproofing — membrane must fully wrap over the curb top and down both sides

- No waterproofing membrane installed behind tile in shower walls, relying solely on tile and grout to stop water

- Membrane not extended high enough on walls, allowing water intrusion at upper wall sections

- Failed flood test due to membrane punctures at drain connection or curb corners

- Incompatible waterproofing product used that does not meet ANSI A118.10 bond requirements for tile overlay

- Missing reinforcement at inside and outside corners where membrane is most vulnerable to cracking

Per IBC Section 1507.1, waterproofing for walking decks over occupied space must be an approved system. IRC R507.1 covers exterior deck requirements. IBC Section 1604.8.3 requires minimum 1/4 inch per foot slope for exterior decks and balconies to ensure positive drainage. ASTM C957 (Standard Specification for High-Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane With Integral Wearing Surface) governs traffic-bearing deck membranes. Per IRC R507.2.2, wood framing supporting waterproofed decks must be preservative-treated or naturally durable.

1. Verify deck surface has minimum 1/4 inch per foot slope to drain per IBC Section 1604.8.3

2. Confirm waterproofing membrane meets ASTM C957 for traffic-bearing surfaces or is an ICC-ES evaluated system

3. Use a mil gauge to check membrane thickness — minimum 55-70 mils dry film thickness typical for ASTM C957 systems

4. Inspect membrane-to-wall transitions — membrane must turn up the wall a minimum of 4 inches above the finished deck surface

5. Verify scupper or drain locations are properly detailed with clamping rings and compatible sealant

6. Check that all metal flashing at perimeter and wall connections is integrated with the membrane system

- Inadequate slope causing ponding water and accelerated membrane deterioration

- Membrane not turned up wall sufficiently, allowing water intrusion at the deck-to-wall junction

- Incompatible pedestals or fasteners puncturing the membrane without proper flashing

- Missing scuppers or overflow drains as secondary drainage in case of primary drain blockage

- Wood framing not preservative-treated per IRC R507.2.2, leading to structural decay

Per IRC R703.8, approved corrosion-resistant flashing must be installed at all locations where required to prevent moisture from entering the wall assembly. ASTM E2112 (Standard Practice for Installation of Exterior Windows, Doors and Skylights) details proper flashing sequencing at openings. IRC R703.4 requires flashing at the intersection of exterior walls and roofs. All flashing must be self-adhering, metal, or a combination system, and must be integrated with the WRB in shingle-fashion per IRC R703.2.

1. Verify head flashing is installed above all windows and doors with end dams and proper WRB integration per ASTM E2112

2. Inspect kick-out (diverter) flashing at all roof-to-wall intersections to direct water into the gutter per IRC R703.4

3. Check through-wall flashing at shelf angles, lintels, and changes in wall construction — must include drip edge and end dams

4. Verify that all flashing materials are corrosion-resistant and compatible with adjacent materials per IRC R703.8

5. Inspect sealant joints at flashing terminations — must use compatible, non-hardening sealant with proper bead geometry

- Missing kick-out flashing at roof-to-wall transitions, a leading cause of concealed water damage

- Reverse-lapped flashing that channels water behind the WRB instead of shedding it outward

- Incompatible metals in contact (e.g., copper against aluminum) causing galvanic corrosion

- Head flashing without end dams allowing water to run off the ends and behind the cladding

- Sealant used as a substitute for proper flashing details rather than as a supplement

Per IRC R405.1, drains must be installed around foundations enclosing habitable or usable below-grade spaces. Footing drains must be gravel-bedded and sloped to discharge by gravity or to an approved sump per IRC R405.1. For above-grade wall systems, IRC R703.7.6 requires weep holes in the bottom course of masonry veneer spaced no more than 33 inches on center. A minimum 1-inch air space or drainage mat per IRC R703.7.4 is required behind masonry and adhered veneer to allow moisture to reach the weep system.

1. Verify footing drain tile is installed at or below the bottom of the footing with filter fabric per IRC R405.1

2. Confirm drain pipe is sloped minimum 1/8 inch per foot toward daylight outlet, dry well, or sump pit

3. Inspect weep holes in masonry veneer — must be present at bottom course, maximum 33 inches on center per IRC R703.7.6

4. Check that a minimum 1-inch drainage air space exists behind masonry veneer per IRC R703.7.4

5. Verify drainage mat or board is installed over below-grade waterproofing to channel water to footing drains

6. Confirm sump pump is properly sized with a check valve and discharges to an approved location per IPC Section 712

- Footing drains clogged with soil or debris due to missing filter fabric

- Weep holes blocked with mortar droppings preventing drainage behind masonry veneer

- No drainage space behind veneer cladding, trapping moisture against the WRB or sheathing

- Sump pump discharge directed too close to the foundation, causing water recirculation

- Drain tile installed above the bottom of the footing, leaving the joint unsealed below drain level