How do I fix squeaky subfloors in my Calgary home before installing new flooring?

The most effective fix for squeaky subfloors is driving screws through the subfloor into the joists from above — this pulls the subfloor tight to the framing and eliminates the movement that causes the squeak. Squeaks happen when the subfloor has pulled away from the joist slightly, allowing the plywood or OSB to flex and rub against the nail or the joist when you walk over it. Calgary's extreme seasonal humidity swings — from 15 to 20% relative humidity in winter up to 40 to 50% in summer — cause the subfloor and joists to expand and contract at slightly different rates, which loosens the original nails over time. This is why squeaky floors are so common in Calgary homes, even relatively new ones.

The screw-down method from above is the standard fix and works in the vast majority of cases. Use #8 or #10 wood screws, 2.5 to 3 inches long, driven through the subfloor into the centre of the joist below. Space screws every 8 to 12 inches along the joist in the squeaky area. The screws pull the subfloor down tight and hold it there permanently — unlike nails, screws resist backing out. To locate joists, look for the existing nail lines in the subfloor (they follow the joists), use a stud finder, or tap the floor and listen for the solid sound that indicates a joist below. A typical Calgary home with squeaky areas in the hallway and a couple of bedrooms might need 50 to 100 screws, costing about $15 to $30 in materials and taking a couple of hours.

If you have access from below (unfinished basement ceiling), the fix is even easier. Have someone walk on the squeaky spot while you watch from below to identify exactly where the subfloor is moving. Then drive screws up through a block of wood into the subfloor, or use construction adhesive along the joist-to-subfloor gap, or insert wooden shims coated in carpenter's glue into gaps between the joist and subfloor. The advantage of working from below is that you do not disturb the subfloor surface.

For squeaks in a specific spot, speciality products like Squeeeeek No More and Counter-Snap screws are designed for driving through existing finished flooring (including carpet and hardwood) without visible damage. These breakaway screws snap off below the surface. They are available at most Calgary hardware stores for about $25 per kit.

When squeaks indicate a bigger problem: If the squeak is accompanied by a noticeable bounce or flex in the floor — if you can feel the floor deflect when you step on it — the issue may be an undersized joist, a damaged joist, or inadequate bridging between joists. This is more common in older Calgary homes from the 1950s and 1960s where joist spans were sometimes pushed to their limits. Excessive deflection requires structural reinforcement (sistering joists or adding support posts), which is a professional job and may require a building permit from the City of Calgary if structural modifications are involved.

Fix squeaks before your new flooring goes in, not after. Once new flooring is installed over a squeaky subfloor, the squeaks will continue — and fixing them afterward means potentially damaging the new floor. If you are having professional flooring installed, a good installer will address squeaks as part of the subfloor preparation. Need help finding an installer who takes subfloor prep seriously? Calgary Floor Installers can match you with local professionals for a free estimate.

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Looking for experienced contractors? The Calgary Construction Network connects homeowners with qualified professionals:

• One OAK Flooring
• Amar Homes Inc
• BOND CONTRACTING & CONSTRUCTION INC
• New Earth Waste Services Ltd
• True North Overhead Doors