What spacing should floor joists be?
Floor joists are usually set at 400mm or 600mm centres, with 400mm the most common for domestic floors. The exact spacing depends on the joist size, span and load.
Domestic floor joists are typically spaced at 400mm or 600mm centres, and 400mm is the common choice as it suits standard board and sheet sizes. Closer spacing allows smaller joists or longer spans.
The correct joist size and spacing for a given span and load come from span tables and the structural design, so always size the joists to the job.
Otis helps a customer work out joist quantities from the floor size and spacing, checks stock and prices the joists and boards together for the account.
General guidance for the trade. Always follow current Building Regulations, manufacturer instructions and the specifics of the job.
See what Otis would capture for you
Book a strategic call and we will model it against your own numbers.