What is a Roof Membrane?

A roof membrane is a roofing system for flat and low-sloped roofs. They are often thin, single layers of material, but thicker, built-up roofs also fall into this category.

Roofing membranes are common in commercial spaces and on RVs, but you can also use them on residential roofs if the slope is less than 3:12. They provide a watertight seal and, depending on the material, can last up to 30 years.

What is a Roof Membrane?View in gallery

If you’re considering membrane roofing for your project, here’s what you should know about the different types, costs, and lifespan.

5 Types of Roof Membranes

Roof membranes aren’t one material – instead, they’re a system for flat roofs. Here are the 5 types to choose from:

  1. TPO Single-Ply Roof Membrane – TPO stands for thermoplastic polyolefin. It’s heat weldable and one of the most affordable single-ply roofing membranes for commercial buildings. TPO is also reflective, which can help cut air conditioning costs making it a good choice for hot climates.
  2. EPDM Membrane  – EPDM stands for ethylene propylene diene monomer. It’s a single-ply synthetic rubber roofing membrane that works well in cold, snowy areas. Since it’s elastic, it can freeze and thaw without cracking.
  3. PVC Roofing Membrane – PVC roofing is a strong roofing membrane that’s durable and puncture resistant. It helps reflect heat, making it ideal for warm climates. It’s typical in airports and restaurants.
  4. Built-Up Roofs (BUR)Built-Up Roofs, also known as tar and gravel roofs, consist of many layers of alternating material. At the base is a sheet of insulation followed by alternating layers of ply sheet and bitumen, topped with an aggregate such as stone or gravel. Thanks to the many layers, BURs are long-lasting.
  5. Modified Bitumen – Modified bitumen is a type of rolled roofing that combines asphalt with rubber and fiberglass reinforcements. Modified bitumen isn’t single-ply but is flexible and watertight.

How Much Does a Roof Membrane Cost?

The cost of a roof membrane varies by location, method of application, condition of the roof, and size. Here’s a look at the average cost of roof membranes, including installation:

  • TPO Roof Membrane: $4.50 – $14 per square foot
  • EPDM Membrane: $4.25 – $12 per square foot
  • PVC Membrane: $5.25 – $12.50 per square foot
  • Built-Up Roof: $3.50 – $7 per square foot
  • Modified Bitumen: $4 – $8 per square foot

According to Forbes, the average flat roof repair is $700. Some common flat roof repairs include fixing the drip edges, fixing seams, and repairing sags.

How Long Do Roof Membranes Last?

The length of time a roofing membrane will last depends on the type, maintenance, and climate. For example, a Built-Up Roof can last 15-30 years, while modified bitumen and PVC last 20 years. A TPO roof will last 7-15 years, and an EPDM roof will last about 15 years.

What’s the Difference Between Thermoset and Thermoplastic Roof Membranes?

A thermoset roof membrane refers to how the strips of roofing attach to each other. The strips chemically bond together, forming one large sheet rather than a roof with many seams. The most common type of thermoset roofing membrane is EPDM.

Thermoplastic roofing membranes are plastic. When attached to the roof, the sheets don’t chemically combine. Instead, the strips connect via heat or solvent. Two of the most popular thermoplastic roofing systems are TPO and PVC.

Frequently Asked Questions (FAQ)FAQ

What’s the best roofing membrane for an RV?

One of the best roof membranes for an RV is TPO. TPO is strong, and since it’s white, it doesn’t absorb heat. One of the biggest cons is that it can crack. Another popular option is rubber EPDM. But since this material isn’t puncture-resistant, low-hanging tree branches can cause issues.

Is PVC better than TPO roofing membrane?

While TPO and PVC are thermoplastic membranes with similar qualities, one of the main differences is that PVC provides more puncture resistance. TPO, on the other hand, is recyclable, while PVC isn’t. 

Is membrane roofing high-quality?

There are varying levels of quality in membrane roofs depending on materials and manufacturers. But overall, membrane roofing is a high-quality option for flat and low-pitched roofs.

How do you install roofing membranes?

Depending on the material and preference, you can install roofing membranes in many ways. Installation methods include heat, adhesive, and peel-and-stick options.

What membrane roofing is white?

TPO and PVC roofing membranes are white. You can also find some white rubber roofing for flat roofs, although most brands offer black EPDM roof membranes.

Final Thoughts

If you have a flat or low-pitched roof, there are many options for covering it. You want to select something appropriate for your climate, that’s watertight, and within your budget. If you live in a hot climate, look for a material with a reflective surface that will help save money on air conditioning.

A roof that can freeze and thaw without cracking is a priority for cold or snowy climates. EPDM is one example. Consult with a roofing contractor before making your final selection.