I am building a vacation home with a self-supporting ridge beam roof structure, and I have sized the interior walls to 70mm + plywood + drywall throughout. I want to build a loft above a central bathroom that will be 3.2x2.4 meters. The span of 2.4 meters is not a problem, but I do not want to thicken the load-bearing walls. The walls should therefore only support the loads from the loft, and not roof loads, as the roof is self-supporting.
My question is, is it possible to construct the interior walls so that they can handle the load from the loft with the maintained thickness of 70mm + double boards? Since it is a wet room under the loft, at least C/C 450 is required according to säker vatten, is this sufficient, or will there be too much deformation?
My question is, is it possible to construct the interior walls so that they can handle the load from the loft with the maintained thickness of 70mm + double boards? Since it is a wet room under the loft, at least C/C 450 is required according to säker vatten, is this sufficient, or will there be too much deformation?
Best answer
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If the width of the loft is 2.4 meters, your 70 mm wall is sufficient. Ideally, the studs in the wall should be of strength class C 24, but C 14 is sufficient even if the margins are worse. The requirement for c/c 450 applies to the wet room's floor joists, not the floor above. It is, moreover, an industry rule, not a standard requirement. If the loft's floor joists have a total length of 2.4 meters, with a wall in the middle under these, you can basically use any dimension.
If the width of the loft is 2.4 meters, your 70 mm wall is sufficient. Ideally, the studs in the wall should be of strength class C 24, but C 14 is sufficient even if the margins are worse. The requirement for c/c 450 applies to the wet room's floor joists, not the floor above. It is, moreover, an industry rule, not a standard requirement. If the loft's floor joists have a total length of 2.4 meters, with a wall in the middle under these, you can basically use any dimension.