Flooring Installation Inspection

Per CSA A136.1 and ASTM F710, substrates must be clean, dry, flat, and structurally sound before flooring installation. Concrete moisture must be tested per ASTM F2170 (relative humidity probe) or ASTM F1869 (calcium chloride). Maximum acceptable moisture levels vary by flooring type but typically 75% RH for most resilient products. Floor flatness must meet a tolerance of 5 mm in 3 m per NBC and industry standards.

1. Verify substrate flatness with a 1800 mm straightedge — gaps must not exceed 5 mm in 3 m

2. Confirm concrete moisture testing has been completed per ASTM F2170 or F1869 with results documented

3. Check that moisture results are within the flooring manufacturer's specified limits

4. Verify substrate is free of contaminants, curing compounds, and loose material

5. Confirm self-levelling compound or patching has been applied where needed to achieve flatness tolerance

- Flooring installed over concrete with excessive moisture causing adhesive failure or warping

- Substrate not tested for moisture before installation

- Floor flatness exceeds tolerance causing lippage in tile or gaps under resilient flooring

- Incompatible curing compounds or sealers left on substrate affecting adhesion

Per CAN/CSA-O115, hardwood flooring must be acclimatized to site conditions before installation — moisture content within 2% of the subfloor. Nail-down installation requires blind-nailing at 200-250 mm intervals into each joist or subfloor. Expansion gaps of 10-15 mm must be maintained at all walls and fixed objects. Subfloor panels must be minimum 15.5 mm plywood or OSB per NBC 9.23.

1. Verify hardwood has been acclimatized — moisture content within 2% of subfloor moisture per CAN/CSA-O115

2. Check expansion gaps of 10-15 mm at all walls, columns, and fixed objects

3. Confirm fastener spacing at 200-250 mm intervals with proper angle and depth

4. Verify no excessive gaps between boards — maximum 0.5 mm for strip flooring

5. Check stagger of end joints — minimum 150 mm offset between adjacent rows

- Hardwood not acclimatized causing expansion, buckling, or cupping after installation

- Insufficient expansion gaps resulting in buckling along walls

- Excessive gaps between boards from improper installation or low humidity

- End joints aligned in adjacent rows creating a visible pattern and weak point

Per CSA A137.1 and TCNA Handbook, tile must be installed with appropriate mortar coverage — minimum 80% coverage in dry areas and 95% in wet areas. Lippage between adjacent tiles must not exceed 1.5 mm for tiles up to 375 mm and 2 mm for larger format tiles. Grout joints must be consistent, full depth, and tooled smooth. Substrate must be rigid enough to prevent deflection exceeding L/360.

1. Check mortar coverage by lifting a tile within 15 minutes of placement — minimum 80% dry areas, 95% wet areas

2. Verify lippage between adjacent tiles — maximum 1.5 mm for standard tiles, 2 mm for large format

3. Confirm grout joints are consistent width, full depth, and free of voids or pinholes

4. Check tile layout for symmetry and balanced cuts at walls and edges

5. Verify substrate rigidity — deflection must not exceed L/360 to prevent grout and tile cracking

- Insufficient mortar coverage creating hollow spots and potential tile cracking

- Excessive lippage between tiles particularly with large format tiles

- Grout joints with voids or inconsistent width

- Tile installed over flexible substrate causing grout cracking

Per CSA A136.1, the substrate for resilient flooring must meet strict smoothness requirements — no irregularities exceeding 0.8 mm over 200 mm. Adhesive type must be compatible with both the flooring product and substrate. Luxury vinyl plank (LVP) and tile (LVT) require expansion gaps per manufacturer specifications, typically 6-10 mm at walls.

1. Verify substrate smoothness meets CSA A136.1 — no bumps or depressions exceeding 0.8 mm over 200 mm

2. Confirm adhesive type is approved by the flooring manufacturer for the substrate type

3. Check seam quality — edges tight with no curling, gaps, or adhesive bleeding through

4. Verify expansion gaps at walls and transitions per manufacturer requirements

5. Confirm material has been acclimatized per manufacturer requirements before installation

- Substrate irregularities telegraphing through resilient flooring surface

- Incompatible adhesive causing bubbling, discolouration, or failure

- Seams opening due to temperature fluctuations and insufficient acclimatization

- Missing expansion gaps causing buckling in floating LVP installations

Per NBC 9.29 and flooring manufacturer requirements, appropriate underlay must be installed for the flooring type. Uncoupling membranes are required for tile over concrete to manage movement and moisture. Acoustic underlay may be required per NBC 9.11 for sound transmission control. Moisture barriers (6 mil polyethylene) are required under floating floors on concrete slabs.

1. Verify moisture barrier (minimum 6 mil polyethylene) is installed under floating floors on concrete per manufacturer requirements

2. Confirm uncoupling membrane is installed for tile over concrete substrates where specified

3. Check that acoustic underlay meets the STC and IIC requirements specified per NBC 9.11

4. Verify underlay seams are properly taped and lapped — minimum 150 mm overlap for moisture barriers

5. Confirm underlay type and thickness are appropriate for the flooring product per manufacturer specifications

- Missing moisture barrier under floating floors on concrete slabs

- Acoustic underlay does not meet specified STC or IIC rating

- Moisture barrier seams not taped or lapped allowing moisture transmission

- Wrong underlay type used for the flooring product

Per NBC and industry standards, transitions between different flooring types and levels must be properly detailed to prevent tripping hazards and protect flooring edges. Height differences greater than 6 mm require a bevelled transition. Thresholds at exterior doors must integrate with the building envelope and weatherproofing. All trim, nosing, and transition strips must be securely fastened.

1. Verify transition strips are installed at all changes in flooring material or direction

2. Confirm height differences between flooring types do not exceed 6 mm without a bevelled transition

3. Check that stair nosings are securely fastened, consistent in projection, and meet NBC stair requirements

4. Verify baseboards and trim cover expansion gaps while allowing floor movement

5. Confirm thresholds at exterior doors are weathertight and properly integrated with the door sill

- Missing transitions between different flooring types creating tripping hazards

- Baseboards pinning floating floors preventing expansion and contraction

- Stair nosings inconsistent in projection creating a tripping hazard

- Threshold at exterior door not properly sealed allowing water intrusion