Strutting plays a useful role in promoting composite structural behaviour of the components that form a timber floor.

The effects of strutting are to:

reduce local deflections by transferring load to adjacent joists (load sharing)
improve joist stability by providing lateral support to joist edges
reduce the effects of vibration that have frequencies above the natural frequency of the floor.

This Wood Information Sheet (WIS) provides an overview of when and why to use strutting in timber floors, types of strutting, and how to install it.

Strutting helps to limit deflection and vibration of timber floors, and improves the lateral stability of individual joists.

There are three types of strutting: timber blocks, timber herringbone and various metal proprietary systems.

The limits on deflection and vibration prescribed in BS 5268-2 remain useful for Design > Engineer;s following the more analytical approach in Eurocode 5.