Can Metal Roofing Be Installed Over Shingles?
Re-Roofing With Metal Roofing We obtain requested this constantly: Can metal roofing could be installed over old fiberglass or asphalt shingles?
The reply is: “Yes it may.” And in so doing, it will save you within the labor and need for tearing from the old roof and also you will not be adding to filling our landfills. Another additional advantage would be that the layers of the old roof will further insulate your house. Metal is the greatest choice because of its really low weight per sq . ft . and it is unique design. Metal roofing weighs under 1 lb per sq . ft .. Asphalt shingles can consider to four pounds per sq . ft . with respect to the brand.
If you won’t want to take our word for this seek advice from the local building department. In certain areas building officials only allow a re-roof more than one layer of shingles. Other locations will help you to re-roof over two layers. Generally it isn’t even a problem if you’re only groing through one layer of shingles.
Referencing Section R907.three of the 2006 Worldwide Residential Code Book® best solutions this, it reads the following:
“Complete and separate roofing systems, for example standing seam metal roof systems, that can transmit the rooftop loads directly the structures structural systems and that don’t depend on existing roofs and roof coverings for support, shall not want removing existing roof coverings.”
When you’re going ahead with this particular project there are a handful of safeguards concerning the underlying material:
Should there be any existing roof leaks, you have to address them and replace any rotten sheeting or rafters. Should there be any indications of problems from the prior roofing weighing an excessive amount of, they have to be also addressed. This might can consist of sagging decking or buckling trusses.
A few options:
A layer of underlayment installed on the top from the existing shingles can help keep your granules from the old shingles from rubbing against the rear of the metal and causing possible corrosion. The standard for underlayment is frequently regarded as felt paper (tar paper) but there’s also many newer synthetic underlayments that can fully trust metal roofing. Standard tar paper includes a inclination that you follow the rear of metal roofing. This could make the paper to tear once the metal roofing expands or contracts because it is made to do. The brand new synthetic underlayments don’t have this issue his or her design exceeds the felt paper standards.
“E-Foil” or foil faced, bubble-wrap type, reflective barrier insulation may also be used like a cushion between your existing roof and also the new metal roofing. The reflective barrier insulation may also lower your cooling cost throughout the summer time several weeks by reflecting heat from your homes roof. Radiant barrier insulation will work the very best when combined with a corrugated panel which has a built-in airspace because of the corrugation. The airspace may also allow natural venting to occur.
I really hope this information has been useful. But here’s yet another factor that you should consider: Are you aware that if you choose metal roofing that this would function as the last decision you are making concerning the roof of your house?