Squeaky Floors: What Causes Them and How They Get Fixed

Subfloor movement, loose fasteners and joist gaps — how to locate a squeak and fix it from above or below.

A squeak is friction. Something is moving against something else — usually the subfloor against a nail, or the subfloor against a joist — and the noise happens as it slips.

Finding exactly where it moves is most of the fix.

The common causes

• Subfloor separating from the joist. A small gap opens between the subfloor panel and the joist below, and the panel flexes down onto it under weight. The most common cause by a wide margin.
• Nails working loose. A nail that has backed out slightly rubs against the wood as the floor moves. Original construction that was nailed rather than screwed and glued is more prone to this.
• Wood movement. Seasonal humidity changes cause expansion and contraction, and in Florida that cycle is real even indoors.
• Flooring itself. Hardwood boards rubbing against each other, or a floating floor with an inadequate or compressed underlayment.
• Bridging or blocking between joists that has loosened.

Locate it precisely

Have someone walk slowly over the area while you listen from below if you have access, or press with your hand while listening from above. Mark the exact spot with tape — squeaks are often a few inches from where you assume they are.

Note whether it happens on the way down, on the way up, or both, and whether it is worse near a wall or in the middle of a span.

Fixing from below

Much easier, and possible where you have crawlspace or unfinished access. Most Central Florida homes are slab-on-grade, so this often does not apply here — but where it does:

• Shim the gap. Where the subfloor has separated from a joist, tap a thin shim with construction adhesive into the gap. Do not force it — driving a shim in too hard lifts the floor and creates a new problem.
• Add blocking between joists where the span flexes.
• Screw the subfloor to the joist from below with short screws that will not come through the finished floor.
• Construction adhesive along the joist and subfloor seam.

Fixing from above

Harder, because you have to work through the finished floor.

• Carpet — you can drive screws through the carpet into the joist below, and specialty kits exist that break the screw head off below the surface.
• Hardwood — screwing from above means countersinking and plugging, and matching the plug to the finish. Doable and visible if done carelessly.
• Laminate and vinyl plank — floating floors cannot be fastened through without compromising them. Squeaks in these usually come from the subfloor beneath or from an uneven substrate, and the fix means lifting the floor in that area.
• Tile — a squeak under tile usually means movement, which is a bigger concern than noise. Tile that moves cracks.

Finding the joist from above is the practical challenge. A stud finder works, or drive a small finish nail through and check from below if you have access.

What does not work

• Powder between floorboards. Talc or graphite quiets a board-on-board squeak briefly. It does not address subfloor movement and it comes back.
• Ignoring a growing squeak. A squeak that is getting worse or spreading means the movement is increasing, which is worth investigating.

When a squeak is telling you something bigger

Investigate rather than silence it if:

• The floor feels soft or spongy underfoot — that is deflection, not just noise
• It appeared suddenly rather than developing over years
• It is near a bathroom, kitchen or exterior wall, where a slow leak may have compromised the subfloor
• There is any staining, odor or visible damage nearby — see our water damage guide

A soft floor near a wet area is a subfloor problem, and covering it with new flooring without repairing it means paying for the flooring twice.

Before new flooring goes down

If you are replacing flooring anyway, that is the moment to fix everything underneath — screw the subfloor down properly, address any soft areas, and level it. Our guide on leveling a subfloor covers the rest.

Inventive Home Improvement handles flooring and subfloor repair across Lakeland and Polk County. Call (863) 633-5499.

Frequently asked questions

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