Metal Roofing Over Existing Asphalt Shingles

Metal roofing weighs less than one pound per square foot.

Metal roofing over existing asphalt shingles.

The low weight of metal roofing is one thing that encourages this. The current roof must be in stable condition with no rot significant dips or severe crowning. You have to in order to comply with local building codes. The vast majority of installations of the metal roofing systems produced by my company are over existing shingles.

Asphalt shingles can weigh up to four pounds per square foot depending on the brand. If you don t want to take our word for it check with your local building department. Your metal roof warranty will be void by installing over asphalt shingles. Local building code in some areas you can install over asphalt shingles but some building codes do not allow it.

It s in compliance with your local building code. Building officials in some areas will only allow a re roof over one layer of shingles while officials in other places may allow you to place the roof over two layers of shingles. As long as the plywood under the shingle roof is in good condition this way can provide many benefits. Steel shingles weigh about 1 4 what asphalt shingles weigh and aluminum shingles weigh about 1 8 what standard shingles weigh.

However to do so you must meet the following requirements. Other issues include venting the eaves and the ridge. When choosing to install a metal roof homeowners need to take into account several trade offs involving cost and performance. It depends on the situation.

Most codes allow only two layers of roofing before requiring a complete tear off. You are using roofing underlayment and vented ridge cap to prevent moisture buildup. Yes you can install a metal roof over shingles. You may decide to install a metal roof over old asphalt shingle roof when.

You shouldn t attach the metal directly to the osb roofing deck. This is by far the most common way to install a metal roof. Metal roofing can be installed directly on top of asphalt shingles. However you ll want to check with your local building department before you make any decisions.

3 install 1 4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1 4 purlins over the shingle roof. In some areas building officials only allow a re roof over one layer of shingles. The metal used for the roof can be tin copper aluminum or steel. Installing metal roofing over shingles is the best solution.