Fixing Squeaky Floors From Above or Below

Squeaky floors come from subfloor panels rubbing against joists, floorboards rubbing against each other, or fasteners that have backed out slightly and no longer hold wood tight against wood. The fix depends entirely on whether the joists underneath are accessible.

Access from below (basement or crawlspace)

This is the easier and less invasive fix, since it avoids disturbing the finished flooring above. Have someone walk the floor slowly above while you watch from below to find exactly where the subfloor flexes away from the joist.

1. Locate the squeak precisely by having someone walk the floor while you watch the joists from below.
2. Where the subfloor has gapped away from the joist, install a squeak-fixing bracket or screw a construction screw up through the subfloor into the floorboard above, being careful not to go so deep it pokes through the finished floor.
3. Where the subfloor rubs against the joist itself, a bead of construction adhesive run into the gap, or a shim tapped gently into a visible gap and lightly glued, closes the movement.
4. For a floor joist that has slightly bowed, a wood block screwed and glued perpendicular between two joists (blocking) can stiffen it.

Access from above (no basement access, or finished ceiling below)

This route deals with the finished floor surface directly, so it is more visible if not done carefully but works when there is no way to get underneath.

• For squeaks between floorboards, specialty squeak-repair screw kits drive a screw through the floor and snap off cleanly below the surface, leaving a barely visible hole to fill.
• Locate the joist first with a stud finder set for joists, since screwing only into subfloor without hitting the joist below does little.
• Talcum powder or powdered graphite worked into the gaps between boards can temporarily quiet friction-based squeaks without any fasteners, though it is a short-term fix.
• For squeaks under carpet, carpeted squeak-fix kits use a jig to guide a screw through the carpet and pad into the joist without needing to lift the carpet.

When squeaks come back seasonally

Wood expands and contracts with humidity, so a squeak fixed in summer can reappear in a dry winter as boards shrink slightly. This is normal and does not mean the repair failed; a small amount of seasonal movement is expected in wood-framed floors and is rarely worth chasing beyond one or two touch-up fixes a year.