IDENTIFYING COMMERCIAL ROOF TYPES
Sprayed polyurethane foam a.k.a. SPF is applied by spraying separate layers with time needed in between applications to allow the previous layer time to dry. The amount of layers vary depending on the R value (thickness) required for each roof. This material can be applied over almost any sub straight or previously installed roofing material. It is easy to identify due to the course texture and bubbles that may appear due to over spraying, or if the foam doesn’t fully adhere to the surface it was applied to.
Different applications
Modified Bitumen a.k.a. Mod Bit. Typically manufactured in thirty-nine inch wide rolls which makes it fairly easy to identify compared to other flat roofing materials. Mod Bit can have three different appearances; no factory coating (looks like thick rubber and is usually topped with a flood coat), granule coated (like an asphalt shingle) and foil surfaced. If you are not sure if you are inspecting Mod Bit or rolled roofing, the best test is to bend an exposed corner. Rolled roofing will begin to tear as the bitumen roof will not. Cap and Base is very similar to modified bitumen in appearance but requires a base sheet that adheres to the sub straight and the bitumen adheres to the base sheet.
Different applications
Built up Roof a.k.a. BUR is one of the oldest and most common flat roofing systems. A BUR consists of several layers or plies of asphalt infused fiberglass felt or ‘ply sheets’ that are hot mopped together using hot asphalt, bitumen or cold applied asphalt and topped with gravel ballast, modified bitumen, or a roof coating such as asphalt (flood coat) or a reflective coating.
Different applications
Ethylene propylene diene monomer a.k.a. EPDM roofing is a single layer rubber membrane. EPDM comes in wider rolls than modified bitumen which is the easiest way to tell them apart. EPDM has more stretch to it than any other flat roofing material and feels softer to the touch.
Different applications
TPO and PVC are different roofing materials but they are difficult to tell apart after installation, aside from markings that may be found near the seams or close to penetrations on the roof. Both of these roof types are single ply membrane. TPO is more durable and impact resistant than PVC. PVC has been around much longer than TPO. They both a have a consistency similar to a swimming pool liner. They are most commonly white but are available in other colors.
Different applications
Common Flat roof coatings
