Hello
I was thinking of switching from metal roofing to concrete tiles on our summer cottage. I've been in the attic to check what the rafters look like and whether they can handle this extra weight.
The rafters are from 1960 and measure 125x50 in the upper arms, with a span of about 5.15m on the lower arm, and the roof pitch is 36 degrees. The rafters are spaced between 105 and 110cm apart. The cottage is in snow zone 2.
Can these handle the load of a heavy concrete tile roof?
If strengthening is needed, how would one do it most efficiently? Alt1: Screw a 75X50 beam under and along the existing upper arms, then place plywood on the side of the existing rafter with glue and screws. This would make them a total of 200mm high.
Alt 2: Place new rafters between the existing ones, dimension 145x45, attached to the wall plate with nail plates and use plywood at the ridge where they are joined. Simply skip the lower arm on this reinforcement.
