A squeaky floor is usually more annoying than dangerous. The sound comes from wood rubbing against wood or against a nail — either the subfloor has separated from the joist below, or floorboards have loosened and shift when walked on. The fix depends on whether you can access the underside of the floor and what type of flooring sits on top.

How to Fix a Squeaky Floor

Why Floors Squeak

Floors squeak for three main reasons:

Subfloor separating from joists: The most common cause. Seasonal humidity changes cause wood to expand and contract, pulling nails loose over time. When you step on the subfloor, it flexes down against the joist and the loose nail slides, creating a squeak.
Floorboards rubbing together: Hardwood floor planks expand and contract, and adjacent boards rub against each other when walked on.
Inadequate fastening: The original construction used insufficient nails or screws, or the fasteners have pulled through the subfloor over time.

Locating the Squeak

Have someone walk slowly across the floor while you listen. The squeak originates at a specific spot — mark it with painter’s tape. If you can access the floor from below (through an unfinished basement or crawl space), go underneath and have someone walk above while you watch and listen for movement between the subfloor and joists.

Fix from Below (Best Method)

If you have access from below — a basement or crawl space — this is the most effective and least invasive repair.

Shim Method

Identify the gap between the subfloor and the joist
Apply a thin bead of construction adhesive to a wood shim
Gently tap the shim into the gap — just enough to fill it, not enough to lift the subfloor
Over-driving the shim creates a bump in the floor above

Screw from Below

Measure the total floor thickness (subfloor plus finish floor) so you do not drive a screw through the surface
Drill a pilot hole up through the subfloor
Drive a short screw up through the subfloor into the finish floor, pulling them together
Use a screw length that is 1/4 inch shorter than the total floor thickness to avoid poking through

Cleat or Block Method

Cut a short piece of 2x4 or 2x6
Apply construction adhesive to one face
Press it against the joist directly under the squeak, tight against the bottom of the subfloor
Screw it to the joist — the block reinforces the connection and eliminates movement

Fix from Above (Carpeted Floors)

When you cannot access the floor from below, you can work through the carpet.

Squeak-Ender Screws

Products like Squeeeeek-No-More provide a special screw and depth-control fixture. You drive the screw through the carpet and subfloor into the joist below. After the screw seats, you snap off the head at a pre-scored breakpoint, leaving the shank buried below the carpet surface.

Locate the joist using a stud finder (joists are typically 16 inches on center, running perpendicular to the floor boards)
Set the fixture on the carpet over the squeak
Drive the provided screw through the fixture, carpet, subfloor, and into the joist
Rock the fixture to snap off the screw head at the break point
The carpet hides everything

Standard Screw Method

If you do not have the specialty kit:

Find the joist with a stud finder
Drive a #8 x 2-1/2 inch drywall screw through the carpet and subfloor into the joist
Drive the screw head just below the subfloor surface
Work the carpet fibers back over the screw head with your fingers

Fix from Above (Hardwood Floors)

This requires more care to avoid visible damage.

Face-Nailing

Drill a small pilot hole at an angle through the hardwood board into the subfloor and joist below
Drive a finish nail or trim screw into the pilot hole
Set the nail below the surface with a nail set
Fill the hole with color-matched wood putty
Touch up with finish or stain if needed

Powdered Lubricant

For squeaks caused by boards rubbing together (not subfloor separation):

Sprinkle powdered graphite or talcum powder along the seam between the squeaking boards
Work the powder into the joint by walking on the area and sweeping excess into the cracks
Clean the surface

This is a temporary fix but often effective and completely non-invasive.

Prevention

When building new floors or replacing subfloor during renovation:

Use construction adhesive between joists and subfloor in addition to fasteners
Screw the subfloor (not nail it) — screws hold better long-term
Use tongue-and-groove subfloor panels that interlock for a stiffer, squeak-resistant floor
Allow hardwood flooring to acclimate to the room’s humidity for at least 72 hours before installation

When to Call a Professional

If squeaking is widespread across an entire floor, the issue may be structural: undersized joists, inadequate bridging, or excessive span. A contractor or structural engineer should evaluate significant floor deflection or bouncing. Isolated squeaks in a few spots are normal in wood-framed homes and are a simple DIY repair.