Loft Conversion Floor Joists Size

Joist size for loft storage i would like to use the loft space for storage and lay loft flooring however i am unsure if the existing joists would support the weight.

Loft conversion floor joists size.

Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor. Joist span and spacing is set by your local building code. I do not plan on ever using it as a habitable space so do not want to spend unnecessary funds on it. This is part 2 in my series of loft conversion videos.

The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example. In this video i show how i cut my my joists make packer plates get the joists from the garden up int. New floor joists are measured and trimmed to size then dropped into the joist hangers and secured in position. Ceiling joists are tied to the floor joists with steel straps to stabilise the ceiling.

The new floor joists of your loft conversion will need to offer at least 30 minutes worth of fire protection which could mean replastering the ceilings in those first floor rooms below. Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors. But larger is not always better when builders are constructing a home or adding a room addition. The loft room will also have to be separated by a fire door either at the top or bottom of the new stairs.

These tables can help calculate whether floor joists are strong enough to support themselves and the load they carry without the help of any walls underneath.