DIY Frequently Asked Questions / Can I install an EPDM rubber roof over an existing roof?
You cannot install an EPDM rubber roof directly over asphalt, tar, shingles or felt paper. Install on 5/8” plywood or OSB. You can install it over existing roofing only if you first place the plywood or OSB decking over the existing roof. Oils in the asphalt and tar roofing will cause problems in the EPDM.