Joining Joists

[lavinpj1]

I've cut out a 1600mm section of rotten 9x3 joist and I plan to replace it with a fresh bit of 9x3. To join the two, I will screw another bit of 9x3 over the joint using M10 coach screws.

What length of overlap should be given on each side of the join and what is the required centre measurements for the coach screws?

 

[noseall]

Wouldn't you be better off with a metal repair shoe or ply gusset each side?

Something 3" thick will be bulky and struggle with the length of the fixings in terms of shear force.

 

[lavinpj1]

Wouldn't you be better off with a metal repair shoe or ply gusset each side?

Something 3" thick will be bulky and struggle with the length of the fixings in terms of shear force.

The joist is about 1" away from a parallel wall so doing anything on the back side would be near impossible. Open to other suggestions about the best way to joint.

 

[noseall]

Cut the lot out and fit another joist or use the wall as a fixing/load carrier.

You can buy 6" screws for example.

 

[lavinpj1]

What are the semantics of bracing off the wall? I assume resin fixings?