"Floor" to crawl space attic?

[Kallebo]

Hello!

What material do you have as flooring in the crawl space at the top above the attic floor?

Is 20 mm raw wood enough? The guy at the timber yard thought that smooth tongue and groove (planed tongue and groove 189kr/m2) was a bit overkill, but that 20 mm raw wood would probably be too weak and was keen to sell the middle ground in the form of 23 mm raw wood. There is barely a meter left to the ridge so it's about a little less than a meter wide walkway to access the gable vents and change the filter in the FTX unit, in other words, no pianos or large crowds are going up there...

 

[leby]

I laid 21mm råspont, works well, holds up to walking no problem at all.

 

[findus42]

Forget about the end joint and splice everything on the rafters so 20mm will suffice.
Regards, Findus

 

[prototypen]

I have laid 22 floor chipboards, if you can just get it up, it goes quickly. In one place I "only" have a 12 mm plywood, and that works too.

Protte

 

[Kallebo]

Okay. Checked at my parents' place and they also have 22 mm chipboard flooring. Then 20 mm raw timber seems better. I'll cut it so that the joints are over the supports. I'll try not to have several joints on the same support!

Thanks for your opinions

 

[KnockOnWood]

I have regular tongue and groove boards (20, 21, or 22 mm?) as an attic floor above a small 55 sqm stable. Up there, I have among other things, stacks of wood, exterior paneling, joists, battens, and interior paneling. So quite a heavy load, but no problems at all. The framework consists of trusses at 1200 mm centers plus intermediate beams, so a total of 600 mm centers. I don't quite remember, but I think we joined completely freely between the framework. Just make sure not to place several joints next to each other and leave at least two turns between joints in the same bay.