Size Bolts To Use For Beam Sistering Attic

Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.

Size bolts to use for beam sistering attic.

If you re scabbing or sistering with members of different sizes it depends. I already have m16 bolts but i worry these might be too big for sistering 50 100mm. Not suitable to put a floor on to act as ceiling attic floor above. Then set new joists same height as existing ones alongside the old.

Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in. When sistering these pieces together it is easy to put just a few nails in the boards and move on. A day until they re level. The room has no ceiling just 5 large oak beams above it running across the width of 5 5m widely spaced sound but bent and twisted.

If you re doing scabs and the members are the same size you ll need more fasteners and you may use glue if you d like. I have read people recommending m8 10 and 12 and have read that using bolts too big might weaken the joist. Ideally nails should be used to temporarily set the piece and then either lag bolts or more preferably carriage bolts should be used to lock them together. Is m16 too big though for a 50 100 joist.

My main question though is regarding the size of coach bolts to use. If you re doing full length sisters and the members are the same size you don t need many fasteners between the members. The north south wall tops above the oak beams have pockets in the stone for beams.