A carpenter is troubleshooting extensive floor squeaks and slight bouncing in a newly constructed residential floor system. The framing consists of 38 mm x 235 mm SPF joists at 400 mm on centre with 19 mm plywood subfloor. Upon inspection, it is noted that the joist-to-subfloor connection uses 63 mm nails with no construction adhesive, and the bridging was omitted. Which combination of remedies will most effectively address both the squeaking and the bounciness?

Question: A carpenter is troubleshooting extensive floor squeaks and slight bouncing in a newly constructed residential floor system. The framing consists of 38 mm x 235 mm SPF joists at 400 mm on centre with 19 mm plywood subfloor. Upon inspection, it is noted that the joist-to-subfloor connection uses 63 mm nails with no construction adhesive, and the bridging was omitted. Which combination of remedies will most effectively address both the squeaking and the bounciness?

Answer options: ✅ Install solid blocking at mid-span and add screws to the subfloor at 150 mm on centre.

• Replace the 63 mm nails with longer 89 mm nails and add diagonal strapping.
• Apply construction adhesive to the existing subfloor and install additional cross-bridging.
• Install metal joist hangers and sister the joists with 38 mm x 235 mm lumber.

Correct answer: Install solid blocking at mid-span and add screws to the subfloor at 150 mm on centre.

Explanation: Floor squeaks are often caused by movement between the subfloor and joists, which can be mitigated by enhancing the connection with screws and ensuring tight joins with solid blocking. Bounciness is often an issue of deflection, and adding solid blocking at mid-span (or maximum allowable spacing) stiffens the floor system, reducing deflection and, consequently, bounciness. Adding screws secures the subfloor, reducing friction that causes squeaks and enhancing the diaphragm action.