Commercial Roofing Liquid Applied Membranes

     The biggest advantage to using this type of material on your commercial flat roof will be its ability prevent leaks by itself; without having to put extra layers on top (though they will work better together).

     When used over existing surfaces such as tar or shingles, some problems may arise; but their biggest advantage is that they are not affected by weather conditions as much as other roofing products .

     Because this type of material offers great protection against water penetration and leaks, it does require some prep work like removing any damaged materials (leaving clean surfaces), removing dirt/grime from the material using a solvent based cleaner if necessary, and then applying a waterproof coating (but only when used over existing flat roofs) . It comes with a limited warranty from the manufacturer should you experience any issues during its lifespan.

     This particular type of product is made out of an organic material similar to felt; which means it will absorb moisture if ventilation beneath your commercial flat roof isn't properly managed. This could lead to problems further down the line, so make sure that when using this product, you properly ventilate and waterproof the roof.

     Commercial roofing liquid applied membrane products are a unique class of commercial roofing materials. They consist primarily of water-based, emulsified or encapsulated resins that meet ASTM C1048 Type I and III designations. As the name implies, they are more akin to a paint than a traditional liquid applied membrane system in which the polymer systems take major part of forming layers on deck and substrate—with resin content usually over 50% by weight.

     One segment is considered as “deposition” type (also called “sparadrap”). The other segment is considered “self-support” type (also referred to as "membrane" or "liner"). Other names used in the industry are “liquid membrane” or “water-based roofing system”. The terminology used can be confusing because the class of materials includes both the water-based emulsified and encapsulated systems, as well as those that contain non-emulsified resins or polymers where the resin content is relatively low (3% - 8%) by weight.

     The commercial liquid applied membrane products market represents a large segment of application area in roofing where it is estimated at over 70 million square metres / year globally. This application includes large home projects, and involves primarily metal and concrete substrates, with limited use on wood or masonry substrates. Asphalt shingle roofs represent a smaller share for this product type. Some manufacturers even produce a “shingle-grade” material to be used on asphalt shingle roofs. This application segment is considered as separate from the traditional, more established liquid applied membrane market which uses polymer systems based on either styrene-butadiene or acrylonitrile butadiene rubber (NBR) elastomer binders. For this reason some manufacturers have started to refer to the water-based emulsified and encapsulated resins as "commercial latex roofing membranes".

      The product type for commercial applications in roofing was developed by applying new technology commonly referred to as “encapsulation process” involving high shear mixing under controlled temperature condition, resulting in latex solution with performance characteristics similar to conventional styrene-butadiene rubber (SBR) based or acrylonitrile butadiene rubber (NBR) based polymer systems.

     These products tend to have lower initial modulus, higher elongation at break and are more sensitive to temperature changes thus will experience longer extension/sag time before reaching equilibrium. They are also highly flexible in cold temperatures and can be applied easily on a roof deck that had been sprayed with ice and snow—something that cannot be done with traditional liquid applied membrane materials. Some of the new water-based commercial latex membrane systems exhibit greater flexibility than even some type of asphalt shingle membranes.

     Using liquid applied membrane products on commercial metal roofing is not ideal. The commercial roofing maintenance membrane material is not considered as a long-term protection for metal substrates, such as galvanized steel, aluminum or copper. It has been shown that the water-based commercial membrane systems will likely have a service life of just over 10 years in some climates and less than that in more severe environments such as cold region (Canada, USA). In these conditions many manufacturers offer specially modified products for metal substrates with performance characteristics better suited to withstand freeze–thaw cycles under low temperatures. Even though there are still some reservations about the long-term durability of this product type on metal substrates, they are excellent alternatives to other types of roofing, such as asphalt shingles and concrete tiles.

     The first commercial application of liquid applied membrane technology began in early 1990s by one company—Shiel Sexton. The initial concept and formulation utilized a modified vinyl acetate-acrylate polymer and an acrylic latex.

     Some manufacturers started the development of products which were based on nylon 6 polymer, but it was soon discontinued as problems occurred with perforation of membranes resulting in leaks. Even though most membrane failures were due to improper application or installation procedures (not following manufacturer’s instructions), rather than material performance specifications, it triggered skepticism over the new product type in the market which still lingers till today among many contractors and specifiers. Due to this reputation, some companies started calling their water-based commercial membrane "self-support" or "membrane" products, to separate them from traditional liquid applied membranes. Find out more about Commercial Roofing Modified Bitumen Products.