Diy Loft Conversion Floor Joists

Sistering is the process of adding a new joist next to each existing joist.

Diy loft conversion floor joists.

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. A basic floor system is installed in about 10 stages from preparation to boarding the floor. 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. In the case of 2x6 joists you can pair them up with additional 2x6 joists by nailing them together side by side.

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. The strong timbers approx 225mm x 75mm timber are secured to the wall plates brickwork and bolted to the walls. The loft room will also have to be separated by a fire door either at the top or bottom of the new stairs.

Once the joists are in all that remains is the noggins cut. Cut the first timber to the required length the distance between the two steels and fix either side using jiffy hangers and repeat with the remaining joists. This allows the board that will butt up to its end to be supported by the 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.

Trimmer joists form the periphery of the new floor. 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. A new floor system is installed using a frame trimmer joists to support the floor joists that span the width of the loft. If the attic joists are not adequate one way to strengthen the floor for live loads is to sister the old joists.

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. You ll use the same size lumber to assemble the rim joists as you will for the main floor joists.