Installation · 7 min · Updated August 2026
Hardwood subfloor prep in Ontario houses
Moisture, flatness, fasteners, and the ugly work that decides whether a GTA hardwood install lasts.
If you skip this, you bought a callback
A 1924 Parkdale joist, a 2019 Vaughan truss, and a King West concrete slab are three different jobs that all get called 'hardwood installation.' Prep is where they diverge.
Moisture first
We meter wood subfloors and concrete slabs. Ontario basements and new slabs fail this test more often than salespeople admit. If the number is wrong, we stop. A plastic sheet and hope is not a moisture plan.
Flatness second
Engineered plank telegraphs waves. Solid oak cups over a hog. Levelling compound, sistering, and sanding high spots are flooring work. They are not extras invented at the end of the quote.
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Estimator first. Site moisture reading second. That is the only honest sequence.
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