Joist dimension in floor??

[marcus133]

I am going to level the floor in the attic to furnish it and have roof trusses at cc1200 mm which are 220x45, span approximately 10 m. I was thinking of short-joisting between these with cc.600. They will therefore be 1155 mm long. What is the smallest joist dimension I need to have?

 

[zankan]

maybe you should check the sizing... the span sounds high there should be a load-bearing wall as well? If that's not there, no noggings in the world would be enough... Personally, I would frame on top of the floor with cross-laid 45*70 c/c 600mm...

 

[marcus133]

Yes, there is probably some of the walls below that are load-bearing. The thing is I would prefer to install the studs between the existing roof trusses, so the question is what dimension I need for the studs since the center-to-center distance between the roof trusses is 1200mm.

 

[marcus133]

Came up with one more thing. What's the best way to fasten them? One thought I have is to set one side in a joist hanger and nail the other side from the backside of the rafter.

 

[frasse]

Beam shoe becomes slightly more stable, otherwise it is common to nail through the floor structure (truss in your case). Then you alternate every other shortling 45mm sideways so you avoid skew nailing.