What are Elastomeric Coatings?

Elastomeric coatings are fluid-applied roofing membranes with elastic properties that allow it to expand and contract with the substrate.

Elongation is important because roofs expand and contract and this allows the roof coating to move with the substrate. It ranges from 300% to 800% depending on the type of roof coating.

Types of Elastomeric Coatings

Water Based

Water-based, acrylic elastomeric roof coatings are widely used over metal and spray foam roofs by contractors and building owners performing DIY restorations. They are best used on roofs that don’t have ponding water.

Solvent Based

Solvent-based elastomeric coatings have higher ponding water resistance and is more suitable for low slope or flat roofs. Solvent-based roof coatings have much better ponding water resistance than acrylic roof coatings.

Check out our full line of Lexis Roof Coating Products.

Application Methods

Airless Sprayer

Airless spray equipment provide quick application and even coverage over uneven roofs with lots of penetrations and rooftop equipment.

Coating Spreader

Roof coating spreaders offer low cost, quick application and clean up over smooth surfaces. They can cover 1200SF a minute. Special profile rollers are available for metal roofs. Spreaders are especially useful on projects where overspray is a concern.

Roller / Power Roller

Foam rollers can be used over flat roofs when applying primers. Long nap rollers are recommended for base coats and finish coats. An power roller can speed up the process.

Membrane Thickness

Proper film thickness is essential to achieve the desired performance in elastomeric roof coatings. In general, elastomeric roof coatings should be applied at a minimum of 20 mils dry film thickness (DFT) to meet the physical properties in the technical data sheet.

Correct film thickness is key to effectively protecting the substrate from UV degradation. A thin coat will not have enough UV blocking and crack bridging capability. This is one of the reasons why we tint our primers to a dark color. A dark surface will show through a thin and uneven coat and make a white coating look gray.

Oftentimes, contractors will sell a 2-coat system but fail to specify the total dry film thickness of the installed membrane. If in doubt, please ask us for details and clarification. Unless specified, they should strive to put down at least 30 dry mils to ensure they are getting at least 25 dry mils on any thin areas.