Diy Loft Conversion Floor Joists

In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together side by side.

Diy loft conversion floor joists.

Trimmer joists form the periphery of the new floor. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists. The loft room will also have to be separated by a fire door either at the top or bottom of the new stairs. A basic floor system is installed in about 10 stages from preparation to boarding the floor.

The strong timbers approx 225mm x 75mm timber are secured to the wall plates brickwork and bolted to the walls. For most jobs 2 in 5 1 cm x 10 in 25 cm boards are an ideal size. This means that new floor joists are fitted alongside them slightly raised above the ceiling plasterboard to avoid contact with it. 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. A new floor system is installed using a frame trimmer joists to support the floor joists that span the width of the loft. 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.

Sistering is the process of adding a new joist next to each existing joist. We can now start installing the joists if you haven t already done so mark out the position of the joists at 400mm centres. Clearing the loft area of all debris insulation struts and temporary boards to expose the ceiling boards. You ll use the same size lumber to assemble the rim joists as you will for the main floor 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. 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.