I have built the frame for the garage and will now lay the roof decking: 95 x 22. It is end-jointed. Does this mean I can place the joints between the rafters and still get good strength if, for example, I need to go up on the roof? Or should the joints still be on the rafters?
No, you don't need to place the joint on the rafters, but you should ensure that it doesn't become a generalskarv, meaning that the end joints do not end up in the same place.
It is probably standard practice to join the tongue and groove between rafters even if it is not end matched.
Just went up in the attic to check. Yes indeed.
Joining over the rafters means nailing very close to the board edge, with a very high risk of the boards splitting.
That’s not ideal either.
But as mentioned, the joints should be spread out so they don’t all end up in the same "bay."
Joining a maximum of every fourth board in the same bay, I believe, is a good guideline.
Just went up in the attic to check. Yes indeed.
Joining over the rafters means nailing very close to the board edge, with a very high risk of the boards splitting.
That’s not ideal either.
But as mentioned, the joints should be spread out so they don’t all end up in the same "bay."
Joining a maximum of every fourth board in the same bay, I believe, is a good guideline.
This means the boards need to be around 4.80 long to avoid joints within the same bay more often than every fourth row.KnockOnWood said:
I think you can join more frequently than that within the same bay. Just make sure to spread the joints within the bay at least 30 cm apart.
You might be right, Vojma!
When I've bought raw boards for my roofs, I've bought a couple of different lengths, 4.8 and 3.6 meters. Then varied the order in which they've been laid so that the seams are spread out.
Update
Now I've been out and looked at the garage roof. The roof overhang is about ten meters. In one truss bay, there's a seam every sixth board. In the other three, there's a seam every third board.
When I've bought raw boards for my roofs, I've bought a couple of different lengths, 4.8 and 3.6 meters. Then varied the order in which they've been laid so that the seams are spread out.
Update
Now I've been out and looked at the garage roof. The roof overhang is about ten meters. In one truss bay, there's a seam every sixth board. In the other three, there's a seam every third board.
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Now I have laid half the roof (= 30 sqm) with seams randomly spread between the rafters. I have also crawled around and laid the under roofing felt and there are no signs of weaknesses at any points. So it's perfectly fine to seam between the rafters. Thanks for all the responses.