Level Your Flooring with the Right Shims & Bridging

Wooden shims are thin, tapered wedges that look like doorstops. They can be used to make slight adjustments to doors and windows, but their primary use is as floor shims to level uneven flooring. Sometimes this can be accomplished by wedging them between a subfloor and floating floor. If the uneven floor is due to warped floor joists, you’ll need to remove a section of subflooring and shim the floor joists. A laser level can help pinpoint the low areas first. Once the subfloor is lifted, attach the shims by gluing and screwing them to the joists. Then plane the area to remove any high spots.

In addition to shimming, you may want to bridge your floor joists as well. Bridging is a quick and easy way to eliminate creaking, sagging or wobbling in your floor. Unlike floor joist blocking, which fastens a perpendicular support piece between two joists to improve load deflection, floor joist bridging uses two support pieces in an “X” shape design. This type of cross-bracing spans the joist space by connecting the top of the width of one joist to the bottom of the width of the adjacent joist. A key benefit of joist bridging is that it’s less likely to cause humps in the floor vs. joist blocking. Pre-made joist bridges are also simple to install because you don’t have to angle-cut the pieces in advance, and they easily fit around plumbing and wiring.