Joist bearing and pointing
90 mm
Timber joists require a minimum bearing surface, typically 90mm, on supporting masonry or timber to ensure stable load transfer
Every figure for this topic is on one page: Floor joists: spacing, bearing, notching and drilling
Read the full answerTimber joists require a minimum bearing surface, typically 90mm, on supporting masonry or timber to ensure stable load transfer. The ends of joists that bear into masonry walls should be protected, often by fully 'pointing' around the joist ends or using suitable plastic/metal web fillers in party walls, to prevent cold bridging and moisture ingress while allowing for timber movement.
Basis in regulation
How to check it on site
Check that all joists have the specified minimum bearing and that their ends in masonry are correctly pointed or protected.
Common failure
Insufficient joist bearing can compromise structural stability, and improperly protected joist ends can lead to timber decay or thermal bypass.
Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.