Hello

This summer, I would made a metal roof with a slope of 7/12 for my house, since my actual roof do have a low slope of arround 3.5/12, and are cover with asphalt shingle.

The house are 20 feet large and width, and the roof 24 feet large and width.

I would build the new roof over the old roof without taking apart the old roof, I would build the new roof trusts (with the steel sheet on it) on the ground and made it raise over the old roof.

Do a finished metal roof (with the steel sheet fixed of the metal roof wood frame) can be lift without braking apart ?

Thank

Bye

Gaetan

You want to build the entire roof assembly on the ground, and then place it on the house? How are you going to pick it up?

I've done a similar project on a house I lived in that had a 2/12 roof. I had scissors trusses built, and cut off the overhangs of the old roof. The truss manufacturer was adamant that the new trusses NOT touch the existing roof except where they rested at the outer edge. I laid a 2X flat and attached it to the old roof deck. The new trusses (about 32' long) were put up by hand with a crew of six. They were then tied with metal fasteners to the original roof trusses to prevent uplift. The framing was then sheathed and roofed in the conventional manner.

Hello

Yes, I would build the entire roof assembly (including the metal sheet fixed on the trusts frame) on the ground, and then place it on the house

I would rent a crane to place it on the house.

Thank

Bye

Gaetan

I'd be concerned about the metal roofing bending or buckling. Lifting the roof as a unit will work provided it's well enough braced, but it probably will flex. No issue if it's covered with Ice and Water Shield, but metal does not flex well.

Hello

OK, I will not raise the finished metal roof, so I will build it step by step on the house old roof.

There is a membrane under the roof shingles, wen I will remove the old shingles, I could not build the truss and put the metal sheets in one day, if it's raining, do the nail holes in the membrane will let the water rain get through it ?

I'm in Canada.

Thank

Bye

Gaetan