Subfloor strength

[AdamCH]

You have a lattice with the lower joists resting on the piers and the upper joists resting on the lower joists at 90 degrees.

All you have to do is put some more upper joist timbers on top of the lower joists at 90 degrees to the uppers & inline with the lowers. I.e. fill in the gaps.

Fix them by screwing through uppers into the noggin ends and down into the lower timbers. Make sure the upper face is level with the upper joists.

Then cut the ply to fall mid way on a joist / noggin. Looks like you have loads of timbers so you won't waste much ply.

Why didn't you just lay thicker joists on the piers? Can't tell what the span is between the piers but you are effectively bridging it with 3" timbers. You'd probably have been better off with one lot of thicker joists.

 

[68breakbreak]

yes I see.. thanks
it's a long story why we didn't just use thicker joists. I was going to work with the structure that was already in place, brought the materials, and then found we had to start again anyway. basically yes I agree, we should have just gone with 6inch/8inch joists, which was the original plan believe it or not!

 

[AdamCH]

yes I see.. thanks
it's a long story why we didn't just use thicker joists. I was going to work with the structure that was already in place, brought the materials, and then found we had to start again anyway. basically yes I agree, we should have just gone with 6inch/8inch joists, which was the original plan believe it or not!

6inch/8inch joists would have been much better. + noggins!

 

[tictic]

OP

you have far to much timber there...imo...you will get a lot of movement in that timber constrution!!

if it was me looking to fix tiles to that floor...i would have it all ripped up and had 145/175mm treated timber, bolted onto walls with a resin insertred in with the wall bolts.. and then 145/175mm joists at 400 centres with joist hangers and dwanged..and then your wbp ply...

again imo you will get movement there...far to much timber so it will be exspanding ect in all differant directions...

 

[tictic]

what are you doing for insulation.......celotex/kingspan ?? ..and how you getting it in there
think you need to re-think before you proceed ere op....or your going to have one very cold floor

 

[tictic]

bump.