While you may have read various claims that rubber roofing is perfectly fine when installed over existing shingles, the reality is that most self installed rubber roofing manufacturers will not honor the warranty on any roof which is not installed on a completely clean surface. So before you begin installing your rubber roofing, you'll have to tear up and dispose your existing shingles, and put down a fresh plywood underlayment if your roof requires it.
Advantages of Self Installed Rubber Roofing
Self installed rubber roofing comes in a variety of styles, in both rolls and shingles of different colors, but all of them are installed in a similar manner. Self installed rubber roofing, if laid correctly, will protect your roof for years in all kinds of weather, and will not be vulnerable to splitting nor cracking. Self installed rubber roofing is an ideal roofing material for large flat roofs.
Because self installed rubber roofing is flexible, it can "breathe" with your roof as the roof expands and contracts in response to changes in temperature. Because of this, self installed rubber roofing experiences much less stress than traditional asphalt roof shingles, and the first rubber roof which was installed in Wisconsin in 1980 is still performing perfectly after nearly three decades of Wisconsin winters!
All self installed rubber roofing, whether shingle or roll style, is attached to the roof's surface with adhesive. So the roof itself must be as clean as possible and have nothing protruding which could piece the rubber roofing when walked on.
The adhesive used to secure the self installed rubber roofing will not set up properly on a damp, dusty, or dirt surface so all water, oil, debris, and dirt should be scrubbed or cleaned up, with a leaf blower used to rid the roof of dust.
Installing The Rubber Roofing
The rubber roofing should then be unrolled onto the area being covered, and cut to fit around any pipes or vents. The roofing should be completely cut and shaped to the roof before adhesive is applied to it, and when it has been cut, the roofing should be rolled up approximately halfway and the adhesive applied thinly to the surface of the roof with a deep nap paint roller . The glue should be applied equally so that it dries flat, and then applied to the self installed rubber roof and given time to set up.
Once the glue has set for a few minutes, the rubber roofing can be rolled out onto the glued roof surface. It's essential to place the roofing material smoothly, because it will be nearly impossible to lift it once it is attached to the adhesive on the roof. Allow the first half of the self installed roofing to dry for an hour and repeat the entire process with the other half!