Our hardwood feels slightly bouncy — does that mean subfloor issues?

Bouncy hardwood flooring usually indicates subfloor problems, though the severity can range from minor deflection to serious structural issues that need immediate attention.

Subfloor deflection is the most common cause of bouncy hardwood. When you step on the floor, the subfloor flexes slightly, creating that springy feeling. This happens when floor joists are spaced too far apart (more than 16" on center), when the subfloor material is too thin for the joist spacing, or when the subfloor wasn't properly attached with adequate fasteners. In older Ottawa homes, you might find 5/8" plywood over 24" joist spacing, which doesn't meet current standards for hardwood installation.

Moisture-related subfloor damage can also create bounce. If the subfloor has been exposed to water damage, the plywood or OSB can delaminate and lose its structural integrity. This is particularly common in basements or areas near bathrooms and kitchens. You might notice the bounce is worse in certain spots rather than throughout the entire floor.

Improper hardwood installation can contribute to the problem. If the hardwood wasn't properly nailed to the subfloor, or if there are gaps between the subfloor sheets that weren't addressed before installation, the flooring system won't perform as a solid unit. The Ontario Building Code requires subfloor deflection to be limited to L/360 under live loads for proper flooring performance.

To determine the severity, walk around and note if the bounce is localized to specific areas or throughout the room. Check if you can see any gaps opening between hardwood boards when you step down, and listen for squeaking or creaking sounds. Minor deflection might just be annoying, but significant bounce can eventually cause the hardwood to separate at the joints or develop cracks.

For a proper assessment of your subfloor condition and potential solutions, it's best to have a licensed flooring contractor evaluate the situation. They can determine if additional subfloor support, replacement, or other structural work is needed before the bouncing damages your hardwood investment.