Framing A New Roof Over An Old Roof

While it might look possible to use the old ceiling joists they would need to be grade checked to make sure they meet the present code.

Framing a new roof over an old roof.

And the variables of design don t stop there the builder must determine the pitch or slope of the roof and use that measurement to figure the total rise from the wall s cap plate to the roof ridge. The exposed edges of the 3 layers of rigid insulation are no longer exposed. You re better off removing the old roof. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option a properly installed layover roof can look and function as well.

This new roof with a higher pitch can be accomplished with premade roof trusses and typical asphalt shingles. You can frame a new roof over the old but it will need to be designed for the span and pitch. Installing new roof shingles over old effectively doubles the weight of the roofing so you have to make sure your roof structure can handle the extra load. A layer of old deteriorating shingles can make your new roof look bad.

Replacing a roof can be expensive but if a roof contains only a small slope it s possible to raise the roof pitch of a house by building a roof over the old one. A roof over a mobile home can also help prevent damage from falling tree limbs as well as cut down on the annoying noise of hearing heavy raindrops falling on the roof. Box beam gable framing new gable overhang is framed in the form of a box beam hanging off of a new layer of roof plywood roof sheathing cantilevered over the top of the 3 layers of rigid insulation. That s also why building codes commonly limit re roofing to no more than two layers.

When necessary to tie the new rafters into the house framing the workers cut into the old roof to make the secure connections. Your roof leaks when it rains if your roof is leaking it s usually better to get rid of the old roof so you can find the source of the problems and fix them. Putting a new roof over a leaking roof won t remove the leaks. But if the current roof is curling this isn t possible.

If your existing roof is fairly old there s a good chance the shingles are damaged. However building the roof will be easier if there are two people working on the roof together.