Squeaky Floors: Causes and Fixes Before New Flooring

Squeaks are usually caused by movement between the subfloor, joists, and fasteners. New flooring over a squeaky subfloor will often squeak too, so fix it first.

Common causes

• Subfloor panels not tight to the joists.
• Nails that have loosened as the wood dried.
• Gaps over joists or missing blocking.
• Seasonal humidity changes in the house or crawl space.

Fixes during a flooring project

• Screw the subfloor down to the joists once old flooring is up.
• Shim gaps from below in a crawl space.
• Add blocking between joists where the floor flexes.
• Level high and low spots before install.

In your quote

Ask whether subfloor screwing and leveling are included or charged per hour, and point out known squeaks during the estimate visit.