Commercial Roofing Terminology 101

As in any industry, roofers like to throw around specific terminology when they talk about their craft. Because roofing is so complex and specialized, roofers need to use this language, but it can be difficult for customers that are unfamiliar with the industry to understand.

Before you start working with a roofing company, it’s good to brush up on some basic terminology. Here are some of the most useful roofing terms and their definitions:

Roofing Materials and Components

Bitumen—Bitumen is a component of asphalt or coal tar, which keeps the roof waterproof. And while it is flammable, it does have a decent fire rating.

Built-Up Roof Membrane—Known as BUR for short, built-up roofing has been around for more than 100 years and uses multiple layers of bitumen in order to increase waterproofing and durability. BUR is not as popular in today’s construction, due to costs. Single-ply membranes are much more cost-effective than BUR installation.

Curb—This is a raised roofing component that is used to raise equipment above a roof surface. These typically surround things like fans, HVAC units, vents, or skylights. Curbs need to be regularly inspected and maintained to ensure that they remain in good condition.

Deck—The roof deck is the surface that everything else goes on top of. It’s the first layer that sits right on the joists. This material is often made of concrete, metal, or plywood. Protecting the roof deck is critical for the health of a commercial roof.

Envelope—The envelope refers to the waterproof seal that protects the base of a roof and a building. A building’s envelope is adhered onto a roof itself and is a crucial component of any roofing system.

Ethylene Propylene Diene Monomer—Also known as EPDM or rubber roofing, Ethylene Propylene Diene Monomer roofs are a cost-effective approach to a new roof system and are composed of recyclable materials. Though cost-effective, EPDM is not necessarily known for its durability in the same way as BUR roofs.

Flashing—Usually made of sheet metal, flashing is used on the edge of roofs to keep it covered and weatherproofed. Flashing is also used around roofing equipment like HVACs or near drains and skylights to keep those areas watertight.

Galvanized Steel—Iron in steel will rust if it isn’t coated. Galvanized steel is coated in zinc so that it does not corrode or rust. Many metal roofs use galvanized steel due to its strength and durability.

Polyvinyl Chloride—Also known as PVC, polyvinyl chloride roofs are a plastic material that sits on top of a roof and has some of the highest ratings for durability, fire-resistance, longevity, and waterproofing. These types of roofing systems tend to be more expensive than other options. PVC is valuable on roofs that contain grease emissions, as the grease will not eat through the membrane like other single-ply roof systems.

TPO—Short for short for Thermoplastic polyolefin, TPO is one of three single-ply roof systems, along with EPDM and PVC (mentioned above). TPO is a more cost-effective alternative with potentially high-energy ratings due to its white reflectivity.

Vents—Vents are any opening used to allow air or vapor to leave a building. Vents should be carefully planned out with roofing contractors, so they don’t become blocked or made ineffective.

Roof Problems

Ice Dam—Ice dams are walls of ice that form on a roof when water or snow freezes. They can cause leaks in a building if left unmanaged.

Thermal Stress—When temperature changes, roof components will expand and contract. This can lead to damage over time.

Water Infiltration—When water or even a small amount of moisture gets into your building, it’s called water infiltration. These leaks require immediate attention.

Wind Uplift—Strong winds can cause a section of a roof to rise. If the roof is not properly sealed, it can cause a section of the roof to blow off.

Your Roofing Terminology Interpreters

Roofing terminology can be useful to anyone investing in a commercial roofing system, but the  Maxwell Roofing & Sheet Metal, Inc. team is happy to walk you through every component of your roof in more accessible terms. To learn more about how we can help get you acquainted with the roofing business, contact us today.