Flooring, Tile & Stone — Quick Reference

Acclimate: 72 hr min (5&ndash;7 days preferred); HVAC at 18&ndash;25&deg;C, 35&ndash;55% RH
MC target: 6&ndash;9% (Ontario); within 2% of subfloor MC
Expansion gap: Min. 12 mm at all perimeters
Nail-down: 50 mm cleats, every 150&ndash;200 mm, within 75 mm of ends
Sanding sequence: 60 &rarr; 80 &rarr; 100 grit + 120&ndash;150 screen

Concrete Moisture Limits

F2170: 3 probes per first 93 m²; 40% depth; 72 hr equilibrate. F1869: 3 tests per first 93 m²; 60–72 hr exposure.

FF/FL: Min. FF 25 / FL 20 commercial; FF 35 / FL 25 for large-format tile.

Tile Size	Notch (sq.)	Coverage	Back-Butter
Mosaic (≤50 mm)	3 mm	80%+	No
100–200 mm	6 mm	80%+	No
200–300 mm	8 mm	80%+	Rec.
300–375 mm	10 mm	80/95%	Rec.
≥375 mm	12 mm	95%+	Required
>600 mm	12–15 mm	95%+	Required

Never skip moisture testing. Every manufacturer requires it for warranty. Cost: a few hundred $. Failed floor: $50K–$150K.
Tile DCOF ≥0.42 wet (ANSI A326.3) for any floor that could be wet. No polished porcelain in lobbies, kitchens, or washrooms.
Flood-test all shower pans & baptistries for 24 hr minimum before tiling.
Epoxy grout below waterline in baptistries — cementitious grout deteriorates in standing water.
Asbestos: Test black cutback adhesive on older buildings before scarifying. O. Reg. 278/05.
Transitions: Max 13 mm height change; bevel at 1:2 for 6–13 mm changes (AODA/OBC).

SLC temperature: Slab and air must be 10–30°C. Cold slab flash-sets compound on contact.
VCT layout: Align grid to main entry, not room geometry — masks out-of-square walls.
Carpet: solution-dyed nylon for sanctuary — resists communion wine stains permanently.
Grout colour: Medium grey or darker for kitchens — white grout is a maintenance nightmare.
Seal cementitious grout after cure — unsealed grout stains within months.