Tongue and groove boards 20x95 mm for garage roof?

[Grillen]

I'm going to replace the roofing felt and noticed that the old tongue and groove boards also need to be replaced due to significant moisture penetration. The old boards are 23x95 but it seems nearly impossible to get hold of them here in town; there's one company that sells them, but it's more than twice as expensive compared to using 20x95. For example, Byggmax and K-rauta have 20x95, but is it too weak, or is it okay to use? The roof has hardly any slope, if that matters.

 

[SueCia]

Moisture penetration? You don't need to replace the roof sheathing just because there are marks from leakage. Only if you have rot in the timber.

 

[Grillen]

I apologize for the poor formulation. It has been very damp and there is rot/mold, and the boards break just by looking at them. The old tongue and groove has been removed and the plan is to build new tomorrow.

The question is whether I can manage with 20mm tongue and groove. I haven't measured between the rafters, but it should be 1.2m. I can double-check tomorrow if needed.

 

[Tokslut]

choose 120 width so you don't have to work so much

 

[Grillen]

True, but some say there's a greater risk of the tongue and groove boards bending/warping if it happens to get humid. We'll see if it ends up being 95 or 120, in terms of work, it's quick anyway because the roof is quite small at 7.5x4 meters.

But that's still not the answer to my question of whether 20mm is too weak?

 

[Snailman]

A few years ago, I nailed up 300 square meters of 20 x 95, between two rafters you shouldn't have a joint on more than every third board (applies when using end-jointed timber).

If you join in the middle of the rafter, you ideally shouldn't have a general joint.

My roof that extends beyond the rafters is visible tongue and groove from underneath, so I always joined that part on the rafters so the joint wouldn't be visible from below.

If you have a short roof like your 7.5 meters, it can be a bit difficult to distribute the joints, as you want the last board against the gable to be attached to at least two rafters.

So the longer tongue and groove you buy, the better. If you buy short ones, it automatically becomes a general joint. I nailed two 75mm nails into each rafter.

 

[NoOne2k]

True, but some say that there is a greater risk for the tongue and groove to bend/warp if it happens to get damp. I'll see if it will be 95 or 120, in terms of work it goes quickly anyway because the roof is quite small 7.5x4 meters.

But that's still not the answer to my question if 20mm is too weak?

There is no problem with 20mm tongue and groove, it flexes a bit more when you walk on it, otherwise it’s fine.

 

[Grillen]

Thank you for those answers. Then it will be 20x95mm. There will be no joints between the rafters, instead, they will be cut so they come in the middle and be spread out.

 

[Tokslut]

120mm(110mm) 1.5 meter less to lay per square meter + the amount of spink is reduced. But if you count every penny, it might be cheaper if you don't value time at all

http://www.byggvarulistan.se/virkesatgang/

 

[Grillen]

There were barely any 120 on the shelf, and what was there was so warped and full of cracks that it wouldn't have been good. But with this small area I have, 95 goes very quickly anyway. But of course, there were no sensible lengths available, only 390cm, and that means a lot of cutting, but I'm doing splicing between the rafters and it feels stable.

But I'm a bit puzzled now that I've found several planks where the end tongue is mirrored, are there 2 different sides of råspont, or is this a miscut? I thought there was only one way so I just picked without checking.

 

[Tokslut]

Where do you shop when they don't even have "basic goods"?

 

[Grillen]

I think every person in this town is building roofs, because the only ones who had the amount I needed were Byggmax and then 20x95. K-rauta, Beijer, XL-Bygg, karl Hedin had very little in stock and some of it was of poor quality. But new supplies should arrive during the week, but I'm in a bit of a hurry to get this up since the roofers are coming on Wednesday to put on the felt, so I had to go with what was available.

 

[Snailman]

Went with 95 because there were hardly any 120 on the shelf, and the ones that were there were so warped and full of cracks that it wouldn't have turned out well. But with this small area I have, 95 goes very quickly anyway. Unfortunately, there were no decent lengths available, only 390cm, so there will be some cutting, but I'm joining between the rafters and it feels stable.

But I'm a bit puzzled now that I've found several planks where the end tongue is mirrored; are there 2 different sides of råspont, or is it some kind of cutting error? I thought they only went one way, so I just picked without checking.

If they don't come from the same wood batch, the end tongue can vary; I believe it has to do with the manufacturer.

Sometimes the placement of the tongue and groove can vary in height from different manufacturers, which is also quite troublesome if you mix them.

I bought a couple of dozen 20x95 today myself; they were 5.5 meters long.

 

[Grillen]

Don't mind my little post about the ends being the wrong way. It was probably a case of sunstroke or something, of course, it's just a matter of turning them around *sigh*

 

[KnockOnWood]

Byggmax and K-rauta have, for example, 20x95, but is it too thin, or is it okay to use? The roof has hardly any slope if that matters.

You probably don't need to worry!
On our house, with a roof area of 190 m2, there is 17 mm raw board.
And it holds