Size Of Floor Joists In Loft Conversion

Floor joists and joist replacement in loft conversions attic dormer and roof conversion extensions.

Size of floor joists in loft conversion. But larger is not always better when builders are constructing a home or adding a room addition. 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. This means that new floor joists are fitted alongside them slightly raised above the ceiling plasterboard to avoid contact with it. The loft room will also have to be separated by a fire door either at the top or bottom of the new stairs.

Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors. How to insulate between new floor joists in a loft conversion using 100 mm rockwool fibre insulation and chicken wire. It is unlikely that the existing ceiling joists will be adequate to support the weight loads that arise from the construction contents and use of a typical habitable room developed in a loft. 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.

New floor joists are measured and trimmed to size then dropped into the joist hangers and secured in position. To overcome this problem new floor joists would need to be installed to take these new loads.