Floor Joist Cross Bracing Has Moved

As shown in figure 2 it is not unusual especially in new homes to find that the cross bridging has not been nailed to the bottom of the floor joists.

Floor joist cross bracing has moved.

As a footstep falls on one joist some of the force is transferred to neighboring joists. Residential building code requires the use of cross bracing or blocking for floor joists exceeding 2 inches by 12 inches but many homes especially older ones have. I have also observed that no twisting or movement issues were found and many homes are 20 years or older. Figure 2 incorrect installation of cross bridging.

Meaning the top end was nailed but the bottm ends were not. Would you consider this an issue after 30 years of no problems and would you recommend they be finished. Bridging or x bracing allows joists to share weight. Figure 1 cross and solid bridging with load on floor.

Thd sku 205173. Install with two 6d common nails per end. Even if your joists already have a row of bridging at the center of the span adding a row on each side of the existing bridging will stiffen the floor. Cross bracing and solid blocking.

How to brace your floor studs. Bracing will stiffen a floor system prevent floor joists from twisting and increase overall stability however there are actually two types of floor joist bracing commonly used.