Modified Bitumen, also commonly known as just “Modified” or “APP or SBS Membranes”. At Summers Roofing we mainly use GAF® Ruberoid®, however, we are also certified installers of Firestone, Mule-Hide, and CertainTeed. For purposes of this web page we’ll be showcasing all GAF® products.
What exactly is Modified Bitumen?
Essentially modified bitumen is base and cap sheets that can be hot asphalt applied, torch applied, or cold process applied (mop down). Your base sheet is usually determined by the type of cap sheet you choose, and just like shingles there are several different types of cap sheets to choose from. Examples below. For a number of years now we have seen architects start to lean more towards the torch applied system, therefore that’s what we are going to discuss on this page.
Types – Torch Down Modified
Several other product types are available by a wide range of manufacturers. Here are a couple of the most used by Summers Roofing.
There are other products on the market for these uses, but Ruberoid® Torch Membrane is among the thickest at 0.148″, making is harder to fully puncture than most alternative products.
- Decks – Modified is a great choice under floating decks.
- Crickets and Dead Valleys
- Flat Roof Systems
- Low Sloped Roofs – If your roof doesn’t have enough pitch for shingles then modified would be a good option, particularly Granulated due to its finished look in a variety of colors.