Guest User
10/31/2004
WHEN INSTALLING METAL ROOF OVER EXISTING SHINGLES, WHAT IS THE PROPER WAY? SOME COMPANYS SAY STRIP WITH 2 X 4'S FOR AIR GAPS. SOME INSTALL FELT PAPER, AND SOME GO ONTOP OF THE SHINGLES. THE MANUFACTUER ONLY RECOMMENDS A MOISTURE BARRIER WHICH COULD BE THE EXISTING SHINGLES. WILL FIBERGLASS SHINGLES HARM THE METAL ROOF IF APPLIED DIRECTLY ONTOP???
Allan Reid
Dura-Loc Roofing Systems, Inc.
11/1/2004
The building code calls for a moisture barrier underlayment under the roof covering unless a product has been tested and approved without one. Each metal roofing system has differant installation criteria. Some are allowed directly over asphalt and some not and it varies between a vaulted roof assembly and an attic assembly. If you lay the metal over the existing roof, there is a good chance that the shingle stone and possibly the joints could telegragh through so if approved it is always best to lay a felt paper in between to help separate them much like a carpet underlayment. Best ask for their residential product approval report issued by the ICC and if they do not have one then that may be an indication and remeber vaulted roof assemblys require a minimum of 1" of vented air space under the roof covering.
Find a Contractor

Get Started Today

Take the first step to increasing the value of your home with a great looking, durable, fire resistant and energy efficient metal roof. Browse our list of qualified MRA Member Roofing Contractors in your area for a free consultation and estimate.