# Epoxy floor in our Mississauga garage plus full basement concrete assessment: moisture testing results

**URL:** <https://home.renovation.reviews/t/epoxy-floor-in-our-mississauga-garage-plus-full-basement-concrete-assessment-moisture-testing-results/46818>\
**Category:** Ontario\
**Created:** [April 26, 2026, 5:33pm UTC](https://home.renovation.reviews/t/epoxy-floor-in-our-mississauga-garage-plus-full-basement-concrete-assessment-moisture-testing-results/46818 "2026-04-26T17:33:50Z")\
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**Author:** ![system](https://home.renovation.reviews/user_avatar/home.renovation.reviews/system/32/77_2.png) [@system](https://home.renovation.reviews/u/system)\
**Post date:** [April 26, 2026, 5:33pm UTC](https://home.renovation.reviews/t/epoxy-floor-in-our-mississauga-garage-plus-full-basement-concrete-assessment-moisture-testing-results/46818/1 "2026-04-26T17:33:50Z")

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We did an epoxy floor coating in our Mississauga attached garage and simultaneously did a basement concrete assessment for a future finishing project. The moisture testing saved us from a major mistake.

**Garage epoxy project:**

2-car garage, 440 sqft, poured concrete from 2004. Concrete was in good condition — minor surface crazing, no heaving, no significant cracks. We went with a contractor-installed polyaspartic system (faster cure than standard epoxy, harder surface, better UV resistance).

Process: Shot blast to open the surface profile (CSP 3-4 required for polyaspartic). Crack fill (3 hairline cracks, $0 extra). Broadcast colour chips (full flake system, medium chip size). Top coat polyaspartic sealer x2.

Cost: $3,200 (440 sqft, all materials and labour). They were done in one day — polyaspartic is drive-on ready in 24 hours vs 72 hours for standard epoxy.

**Basement moisture assessment:**

We want to finish the basement. Before getting quotes, we did the plastic sheet test on 6 spots around the slab. Two spots (near the sump pit and one corner) showed significant condensation at 72 hours — indicating vapour transmission above acceptable levels for organic floor materials.

We rented a slab moisture probe and tested RH at 40% depth: the two problem spots were at 82% and 79% RH. Polyurethane LVP requires max 75% — we are over limit at those spots.

**What this means for our finish plan:** We will need either a moisture mitigation system (penetrating silicate sealer or full epoxy vapour barrier coat on the slab before the sleeper floor system) or a sleeper floor system on rigid foam with no organic top layer in the high-moisture corners. We now have a realistic scope to price.

Spending $180 on moisture testing before choosing finishes is the best money we spent on this project.