Timber joist and deck floors – avoiding movement

Timber joist and deck floors – avoiding movement

Date Published

21 August 2022

Document Type




Member-Only Resource
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This Wood Information Sheet (WIS) gives guidance specifically intended to minimize problems of movement and noise in timber floors in masonry or timber frame buildings. The guidance relates mainly to dwellings although much is applicable to floors in other building types, such as timber compartment floors in flats.

This WIS can be used as a checklist for designers and site supervisors to ensure that timber floors give continuing satisfactory performance.

This sheet does not cover the design information readily available in documents, for example thermal insulation and ventilation.

Key Information

Noise and movement problems are not normally indicate of structural defects but the disruption to occupants and the cost of remedial action can be high.

Excessive notching or drilling can, in extreme cases, result in structural failure. In other cases it is likely to result in increased floor deflection and increased ‘bounce’.

Don’t mix solid and Design > Engineer;ed timber within the same floor zone.