When to lay OSB floor

[Jupiter01]

Struggling with the order in which I lay the above and wanted your thoughts please.

I am building a garden room with this type of floor and foundation system.

Initially, I was planning to lay the OSB floor and then crack on with walls and roof.

Practically, this will be challenge as I am likely to build this over a few months and it will get wet. Whilst all the timber is treated, the OSB board wont cope too well? Can I build the stud walls on to the floor joists and then out the roof on and finally, come back to the OSB Floor. Would this approach - or some other - work?

Thanks in advance.

 

[endecotp]

Initially, I was planning to lay the OSB floor and then crack on with walls and roof.

So that the edge of the OSB would be on the outside of the structure? That doesn’t sound like a good idea. What is your proposed wall construction?

the OSB board wont cope too well?

Correct.

Can I build the stud walls on to the floor joists and then out the roof on and finally, come back to the OSB Floor.

Yes. The OSB should ideally be supported by timer all around the perimeter, but in practice you can probably support it on insulation.

 

[Jupiter01]

So that the edge of the OSB would be on the outside of the structure? That doesn’t sound like a good idea. What is your proposed wall construction?

Yes initially the edge of the OSB would be visible externally. Once the stud walls are built, I will line with plywood and that would go down near the floor, covering OSB edge. It will then be wrapped with a membrane and I will then clad.

Yes. The OSB should ideally be supported by timer all around the perimeter, but in practice you can probably support it on insulation.

This was my main concern. Where would I screw the edge of the osb. There will be insulation in the floor, between the joists.

 

[endecotp]

Where would I screw the edge of the osb. There will be insulation in the floor, between the joists.

Floating floor surely?

 

[Jupiter01]

Floating floor surely?

Sorry, I don’t follow. The edges of the OSB board won’t be screwed down or resting on anything. Is that an issue?

 

[freddiemercurystwin]

You're splashing out on 6x2's for the studs and then skimping on the floor with some OSB? Bonkers! Use plywood for the floor as you know you should and cover it with a tarp until you can get the walls/roof over it.

 

[endecotp]

The edges of the OSB board won’t be screwed down or resting on anything.

They would be resting on the insulation. It’s preferred to have timber around the perimeter, but you can probably get away without. That’s assuming that the insulation is not just jammed in between the floor joists.