Putting Metal Roofing Over Old Roofing

Some roofers install a layer of waterproof shingle underlayment wsu over the existing shingles at the eave end as would be done for a roof laid on bare sheathing.

Putting metal roofing over old roofing.

Doesn t provide the flattest surface for the metal roofing to be installed over each course of shingles is about a 1 8 higher than the course just below it. March 11 2020 by safe harbor roofing. This provides added protection against ice dams. But is this a good idea.

To vent the roof holes are cut in the old roof detail 1 above the soffit which pulls air through the soffit vents underneath. 3 install 1x4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1x4 purlins over the shingle roof. Installing metal roofing over existing roofing material can usually be successfully. 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.

Pros and cons for metal roofing installation. Metal over metal retrofit considerations there are a number of issues a roofer will have to deal with when it comes to metal over metal retrofits but listed below are a few where the use of a roof hugger. Should you tear off the old roof and start over or simply remove the fasteners from the existing roof and install another roof over it. Be sure the larger edge is laid so that the small edge of the next panel will overlap it.

Reroofing is the practice that involves installing a new roof over an existing one. Align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof line. Should old shingles be removed before new installation. Cool outside air then travels under the shingles to the vented ridge detail 2 pulling out moisture and heat.

However installing new flashings including special drip edge flashings made for reroofing will ensure a tight seal and a long life. The installation of metal roofing is often easier and faster than other roof types and because of its simple design and generally large size can actually be installed directly on top of existing roofing materials like asphalt shingles and foam roofing.