New Floor Joists Loft Conversion

The normal live load for domestic floors is as you will know 1 5kn m about 30lbs sq ft in old money.

New floor joists loft conversion.

Where you re adding a large dormer. This means that new floor joists are fitted alongside them slightly raised above the ceiling plasterboard to avoid contact with it. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. 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.

Most loft conversions employ at least one pair of steel beams to support the new floor structure and the roof slopes at purlin level and sometimes also at ridge level e g. This is part 4 in my series of loft conversion videos where i show the viewer every aspect of my diy loft conversion. Where headroom in. 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.

In this video i fit more joists up to t. The loft room will also have to be separated by a fire door either at the top or bottom of the new stairs. As these joists support the existing ceiling and restrain the pitched roof from spreading you must provide replacement support such as timber trimmers around the opening. The new elements which help to form the new loft room s are broadly.

The opening for new stairs is normally formed by cutting away some of the ceiling joists between the existing loft space and the floor below. There are many ways of altering roof structures for loft conversions but they all have one common element the ceiling joists will almost certainly be inadequate as floor joists.