Repair & structural
The subfloor decides whether a new floor lasts 30 years or starts failing in one. Kitchener Prestige Flooring repairs and replaces subfloors for homeowners, renovators, builders and property managers throughout Kitchener and Waterloo Region.
Our team has more than 16 years of experience and 1,700+ jobs completed, many of them in century homes with original plank subfloors. We find rot, soft spots and weak framing before they ruin a new floor, not after.
We are licensed, insured and WSIB covered. Every subfloor repair is backed by our written 1-year labour warranty and listed as its own line on your quote.
Every floor covering depends on the layer under it. A soft, uneven or wet subfloor causes squeaks, gaps, cracked tile, broken vinyl joints and cupped wood.
Many quotes skip this layer and assume the subfloor is fine. When the old floor comes up and the problems appear, the price changes, or worse, the new floor goes down over them.
We inspect the subfloor during the estimate and price repairs as a separate line, so you know what you are paying for and why.
These are the four problems we find most often in Waterloo Region homes.
Slow leaks around toilets, tubs, dishwashers, fridges and exterior doors rot the subfloor quietly for years. The floor above may look fine until it goes soft.
We cut out every soft or stained section back to sound wood and replace it with new plywood.
Oriented strand board swells at the edges when it gets wet, and it rarely shrinks back. Swollen seams show through vinyl and laminate as ridges.
Mild swelling can be ground flat. Delaminated OSB, where the layers separate, is replaced.
Older homes and some additions have joists that are too small for their span, or were notched by plumbers and electricians over the years. The floor bounces and sags.
We add sister joists, blocking or mid-span support where needed. Major structural changes may need an engineer or a permit, and we will tell you when they do.
Nails work loose as wood dries and moves, letting the subfloor lift off the joists. That is the source of most squeaks.
We re-fasten the subfloor with subfloor screws and construction adhesive before new flooring goes on. Specific squeak work is covered on our squeaky floor repair page.
We cut out damaged sheathing with cuts that land on the centre of a joist, so both old and new panels have solid bearing. Where a cut falls between joists, we add blocking underneath.
New panels are tongue-and-groove plywood matched to the existing thickness. They are glued with subfloor adhesive and screwed every 6 inches along the edges and 12 inches in the field.
Panel ends are staggered and gapped slightly to allow for movement. The patch is then checked for flatness against the surrounding floor.
Tile needs a much stiffer floor than carpet. These are the minimums we work to for joists spaced 16 inches on centre.
| Floor covering | Minimum subfloor we install to |
|---|---|
| Carpet, vinyl plank, laminate | 5/8 inch tongue-and-groove plywood or OSB |
| Nail-down hardwood | 3/4 inch plywood, or 23/32 inch OSB |
| Ceramic and porcelain tile | 3/4 inch plywood plus uncoupling membrane or second layer |
| Natural stone | Two layers of plywood, about 1-1/4 inch total |
Joists at 19.2 or 24 inches on centre need thicker panels. Flatness is a separate issue, covered on our floor levelling and patching page.
Wood subfloors should read 12% or less on a pin meter before any flooring goes down. Wood flooring also needs to sit within 2 to 4% of that reading.
Concrete subfloors are tested with humidity probes or calcium chloride kits. High readings need a barrier or mitigation first.
Moisture problems below the subfloor, especially in crawl spaces, are handled through our floor vapour barrier installation service.
Homes built before about 1950 in Kitchener, Cambridge and Guelph usually have subfloors made of 1x6 or 1x8 boards, often laid diagonally. They are strong but rarely flat.
The boards have gaps, cupping and nail pops from a century of seasons. Thin floors like vinyl, and rigid floors like tile, show every flaw.
We re-fasten the planks with screws, then add a plywood underlayment, glued and screwed, for tile, vinyl and floating floors. Solid hardwood can usually go directly over sound planks, laid across them.
Subfloor work is its own line on our quotes because its cost varies so much from house to house. Showing it separately lets you compare quotes fairly.
Typical 2026 ranges in Waterloo Region:
| Item | Typical cost |
|---|---|
| Re-screw existing subfloor | $0.75 to $1.50 per sq ft |
| Replace damaged sheathing | $6.00 to $12.00 per sq ft |
| Plywood underlayment over plank subfloor | $2.50 to $4.50 per sq ft |
| Sister a joist | $150 to $400 each |
A quote that says nothing about the subfloor may be optimistic. Leaks that caused the damage are covered on our water damage floor repair page. All subfloor work carries our 1-year labour warranty.
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FAQ
Straight answers to the questions we hear most. Still unsure? Call and ask.
Ask for a Free QuoteWe look for soft spots, dark staining at seams, spongy areas around toilets, tubs and exterior doors, and high readings on a moisture meter. From the basement we probe the underside of the sheathing with an awl. Opening a small inspection cut confirms it.
On joists at 16 inches on centre, we want at least a 3/4 inch plywood subfloor plus an uncoupling membrane or a second layer of plywood. Natural stone needs a stiffer floor still, often two layers of plywood.
Sometimes. Small areas, such as around a toilet or under a dishwasher, can be cut out and patched if the finished floor above can be lifted in that spot. Widespread damage usually means removing the floor covering in that room.
For tile, vinyl and floating floors, yes. The gaps and cupping in old board subfloors show through thin floors and flex under tile.
A plywood underlayment, glued and screwed, gives a flat, stiff surface. Solid hardwood can often go straight over sound planks.
Free estimate
Tell us about the floor. We will call to book a time, measure on site, check the subfloor and moisture, and leave you a written quote.
Prefer to talk it through first? Call and speak to a flooring specialist directly.
Kitchener Prestige Flooring
137 Glasgow St, Kitchener, ON N2M 5E3
Monday to Saturday: 7:00am to 9:30pm
Sunday: 9:00am to 9:00pm