Tile Installation Inspection

Per ANSI A108.01, the substrate must be flat within 1/4" in 10 feet for tiles with any edge 15" or longer, and 1/4" in 10 feet for smaller tiles. Substrate must be structurally sound, clean, and properly waterproofed in wet areas per TCNA methods.

1. Check substrate flatness with a 10-foot straightedge — max 1/4" variation

2. Verify cement board or equivalent substrate in wet areas (not drywall)

3. Check for waterproof membrane in showers, tub surrounds, and steam rooms

4. Tap substrate to check for hollow spots or delamination

5. Verify proper deflection control (L/360 minimum for floor tile)

- Uneven substrate causing lippage between tiles

- Missing waterproofing membrane in wet areas

- Excessive floor deflection causing cracked tiles and grout

- Improper substrate material for the application

Per ANSI A108.02, tiles must be laid with consistent grout joints. Lippage (height difference between adjacent tiles) shall not exceed 1/32" for rectified tiles and 1/16" + allowable warpage for standard tiles. Cut tiles should be symmetrical and no less than half a tile width at walls.

1. Check grout joint width consistency — should be uniform throughout

2. Use a lippage gauge or straightedge to verify maximum 1/32" lippage

3. Verify layout is symmetrical with no narrow slivers at walls

4. Check that tile pattern is consistent and aligned

5. Confirm tiles are level (floor) or plumb (walls)

- Excessive lippage between adjacent tiles

- Inconsistent grout joint widths

- Narrow tile cuts at walls (less than half tile)

- Misaligned patterns or crooked rows

Per ANSI A108.5, minimum mortar coverage must be 80% for dry areas and 95% for wet areas and exteriors. Tap tiles to check for hollow spots indicating voids. Hollow-sounding tiles indicate insufficient adhesive coverage.

1. Tap tiles with knuckles or a rubber mallet — solid sound indicates good adhesion

2. Check for any tiles that move or flex when walked on

3. Verify no hollow spots especially in wet areas and high-traffic zones

4. If accessible, check mortar coverage pattern on removed tile (should show 80%+ contact)

5. Confirm tiles at floor drains slope properly toward drain

- Hollow tiles from spot-bonding instead of full coverage

- Tiles debonding from insufficient mortar or wrong mortar type

- No slope toward drain in shower floors

- Tiles cracking from voids under high-stress areas