Diy Loft Conversion Floor Joists

This means that new floor joists are fitted alongside them slightly raised above the ceiling plasterboard to avoid contact with it.

Diy loft conversion floor joists.

If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. We can now start installing the joists if you haven t already done so mark out the position of the joists at 400mm centres. This allows the board that will butt up to its end to be supported by the joist. The rim joist sits vertically on top of the sill plate along the outside of the frame to create a lip for the main floor joists.

For most jobs 2 in 5 1 cm x 10 in 25 cm boards are an ideal size. Trimmer joists form the periphery of the new floor. The loft room will also have to be separated by a fire door either at the top or bottom of the new stairs. Remember to double up the joists where the stairs are going to be installed and to treble up the joists under the dormer walls of our loft conversion.

The strong timbers approx 225mm x 75mm timber are secured to the wall plates brickwork and bolted to the walls. A new floor system is installed using a frame trimmer joists to support the floor joists that span the width of the 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. If the board overhangs mark it at the centre of the last joist it crosses and make a straight cut at this point with a jigsaw.

Once the joists are in all that remains is the noggins cut. In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together side by side. You ll use the same size lumber to assemble the rim joists as you will for the main floor joists. 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.

If you intend to board directly on to the joists instead of having a raise floor then start by placing the first board across the joists. Clearing the loft area of all debris insulation struts and temporary boards to expose the ceiling boards.