Although asphalt shingles are a still popular roofing choice, homeowners with flat roofs often opt for the elastomeric membrane.

While it has many advantages, elastomeric membrane roofing still isn't as well known as other roofing options available on the market.

And, that's why we've decided to list the 7 things you should know about this type of roofing.

Everything About Elastomeric Membrane Roofing

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1- It’s expensive

Since renovation material choices are closely linked to your planned budget, it’s difficult to ignore this aspect. Thus, it’s important to mention that elastomeric membrane roofing costs between $9.50 and $15 per square foot, a price that’s comparable to sheet metal.

Therefore, this roof covering is more expensive than traditional asphalt shingles. However, it should still be emphasized that the elastomeric membrane has a long service life if it's properly maintained. More specifically, its durability is estimated between 25 to 40 years.

2- It's made up of 2 layers

The elastomeric membrane is actually made up of two layers, which is why it’s categorized as being bilayer. More specifically, it can be said that the elastomeric membrane has a base membrane as well as another layer that acts as a finishing coat.

The latter consists of very fine ceramic grains which give it its final colour, which is often gray or white. Note that it's also available in green, beige or brown gravel.

3- It can be installed in two different ways

Unlike most materials that have a well-defined installation technique, elastomeric membrane roofing is done in whichever two ways. As a matter of fact, it can be installed by torch, which allows the two coats (the main coat and the topcoat) to adhere together. And, since the joints are fusion welded, this method ensures the roofing is properly sealed.

Subsequently, note that elastomeric membrane roofing can also be installed using sections of membrane fitted with self-adhesive strips, allowing the different parts to bind together. This cold-laying technique limits the risks of fires posed by the first suggested method.

In either case, it’s essential to hire expert hands to ensure that the membrane is installed correctly. Otherwise, the seal could be compromised. Moreover, note that certified roofers have the knowledge required to prevent fires from occurring if the membrane is installed using a torch.

In addition, keep in mind that forgetting certain welds (around ventilation devices, skylights or plumbing vents) can compromise both the membrane's seal and its durability.

4- It has numerous advantages

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Right off the bat, let's just say that elastomeric membrane roofing is very resistant to impact, temperature variations, and ultraviolet rays. Why's that? Well, first, because it has a granulated topcoat, which is a very effective form of protection, and second because it has remarkable elasticity. Due to this material’s strength, the elastomeric membrane requires little repair to remain in good condition.

Generally speaking, note that elastomeric membrane roofing requires little maintenance. On that note, it’s especially recommended that you inspect your roof once a year to ensure that certain areas don't need to be repaired. Also, it’s essential to ensure that the roof drain functions properly so that it can effectively evacuate water from the roof when needed.

5- Water can damage and shorten its service life

Despite its durability, elastomeric membrane roofing can't withstand the presence of stagnant water on its surface. Thus, ice, as well as algae, can deteriorate the aggregate if these substances remain on the roof for an extended period. This is why we strongly recommend installing a drain that's at least 4 inches wide on the roof to drain any stagnant water.

6- It’s mostly used on flat roofs

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Typically, this type of roofing is used on flat or very low-slope roofs, most often on commercial or institutional buildings. Although, it can be used on sloping roofs as an underlayment.

7- It’s not an eco-friendly choice

Unfortunately, since elastomeric membrane roofing is a derivative of asphalt, and strictly speaking, it’s not an eco-responsible choice. In fact, right now, this type of roofing isn’t recyclable in Quebec.

Need more information on the subject? Check out these articles:

• Flat roof maintenance: what you need to know

• Renovation Guide: fixing your roof 

• Why regular roof maintenance is essential

Want a cost estimate for your roof renovation project? Try our cost calculator!