Roof coating protects your building from the elements
A roof is one of the most important parts of a building. It protects the interior from the seasons, wind, sun, rain and even snow. Your roof needs to be a solid barrier between your building and the elements, and a roofing failure can lead to thousands of dollars of damage and repair or replacement work. The quality of your roofing system impacts your investment and assets. One way to protect it is with roof coating.
In the United States, liquid coatings are the fastest growing sector of the flat roof refurbishment market. Roof coating can not only waterproof and prevent deterioration, but also improve the cost and energy efficiency of your building. In this article we will outline the different types of roof coating, which is best for your needs, and where to find roof coating solutions in the US.
Roof coatings for all types of roofs
The coating type you choose for a roof project depends on the roofing material and the slope of the roof. Flat roofs and pitched roofs have different needs and there are different materials suitable for each. Windy, rainy, snow-prone or sunny environments all have different demands.
- FLAT ROOFS: These are more common for commercial and industrial buildings. They are the most cost efficient roof shape because they have a smaller surface area and so need less material. The danger with flat roofs is leaking and water pooling, so the main goal in coating them is to create a waterproof barrier. A roof coating on a flat roof is applied over the pre-existing membrane, usually asphalt or rubber.
- PITCHED ROOFS: These allow for shingles and tiling, meaning water and snow can easily drain and there is less risk of leaks. Tiling also has the benefit of allowing spot fixes, where fixing a leak may be a simple case of fixing the tile. When coating a tiled roof, the aim is to waterproof and provide UV protection for the tiles themselves, extending the life of the actual tiles.
Extra: If your project includes asbestos encapsulation, a liquid roof coating can provide you with the least difficult method of dealing with it. Attempted removal of asbestos can release the asbestosis-causing material, but with a liquid coating you can seal in the asbestos without having to disturb it, and protecting it from further interference.
Choose the best of the 4 roof coating options for you roof
Liquid roof coatings provide a seamless (“monolithic”), unbroken and smooth surface to your roof. They cure to a rubber-like waterproof membrane, which can be reinforced with additives or secondary materials for additional tensile strength or protective properties. Liquid roof coatings can be applied over most roof materials, including asphalt, concrete, metal, bitumen, felt, and more, though some may require priming. Each manufacturer and roofing contractor has their own formulation, but these are some of the basic roof coatings:
1. Polyurethane, polyurea and polymeric roof coatings
These coatings (also known as “cold liquid applied” roof coatings) are applied to a roof as a cold liquid, forming an elastomeric waterproof membrane. They are capable of stretching with the substrate without being damaged. Cold applied liquid coatings are rapid curing even in winter, have excellent adhesion to a variety of substrates, and are cost-effective. Polyurea in particular has outstanding physical properties and can resist permanent standing water conditions.
PROS: Excellent tensile strength, high resistance to temperatures (-40°F to 176°F), stretch with the substrate, chemical resistant, UV resistant, more traffic and impact resistant than other coatings. Good for ponding water conditions. Can be applied on roof tiles.
CONS: More expensive than acrylics, wear at the same rate as acrylics.
2. Bituminous and modified roof coatings
Also known as asphalt or coal-tar pitch, bituminous coatings are highly sticky and viscous organic liquids used for waterproofing a roof. Aluminum pigments can be added for reflectivity, and the bitumen can be modified with polymers for improved physical qualities.
PROS: Versatile, can be applied to asphalt. concrete, asbestos (for encapsulation), cement or metal sheeting, and built-up felt. With aluminum can deflect UV and heat from the roof.
CONS: Not as flexible as other coatings (unless modified), requires heat to cure. When modified can last 10 to 20 years. Mostly used as industrial roof paint.
3. Silicone roof coatings
Inorganic, moisture-cured coatings made of liquid silicone. Silicone coating can expand and contract with a substrate, providing thermal shock protection through temperature changes.
PROS: Silicone coating is highly UV resistant, elastomeric, impermeable, environmentally friendly, withstands ponding water, good weathering capabilities.
CONS: The most expensive coating option, and they lose their reflectivity over time. If the roof needs recoating it must be done with silicone or the previous silicone coating must be removed completely. Not resistant to tearing.
4. Water based acrylic roof paint
This is the most cost effective liquid waterproofing system. A single component system, water-based acrylics are applied 5-10 times thicker than a house paint. Titanium dioxide (TiO2) is added to make the coating more durable and reflective. The white colour reduces the temperature of the roof, reflects sunlight, and so reduces the temperature of the interior and air conditioning costs. By reducing temperature and UV radiation TiO2 also protects the roof from deterioration, increasing its life. A zinc oxide additive (ZnO) can also improve reflectivity, as well as resisting mildew and algae growth.
PROS: They are highly reflective, UV resistant, cost effective, and easy to work with.
CONS: Acrylics will lose thickness due to weathering, require temperatures above 50°F for application, and typically do not perform well in water-ponding situations.
Services in the US – industrial roof coating & commercial roof painting
Given the importance of roofing to the stability of a building, it is unsurprising that roof coating services are available from many providers across the States. There are also plenty of products available for those looking to protect their shingles from the elements. Flat roof coating, however, is a specialist application job, requiring the expertise and training of professionals. If you would like more information, or want to be connected with one of our coating partners, contact us! Our experts are here to help. Get in touch by clicking the “Request a quote” button at the bottom of this article.
DIY roof coating products on the US market
In the US there is a whole range of waterproof roof coatings, sealants and roof tile paints available. Whether you are looking to protect, decorate or repair your roof; there is a product to suit your needs. Keep in mind that a large roof coating job can be difficult without proper equipment, knowledge and preparation. If you’re not sure, we’ll recommend one of our partners approved applicators to come and do it for you! Take advantage of our 100% free quoting service by clicking the “Request a quote” button at the bottom of this article.
|Roof coating brand||Roof coating product||Price (MSRP)||Theoretical coverage||Substrates|
|Dyco Paints Inc||890 Roof Coat||$24.11 (1 qt)||200-300 sq. ft. per gallon||galvanized metal aluminum and asphaltic coatings|
|Dyco Paints Inc||Bulldog Elastomeric roof coat||$47.90||–|
|Henry||Tropi-Cool||$265.48 (4.75 gal.)||100 sq. ft. per 1.5 gallon||Aged asphalt roofs, including Built-Up Roofing (BUR) and Modified Bitumen (MB), Aged single-ply roofs, including EPDM, TPO, PVC, and Hypalon® roofs, Spray polyurethane foam (SPF) roofs, Metal roofs, Concrete roofs, Recoating previously coated roofs, RV, trailer, and mobile home roofs|
|Henry||Premium Aluminum Roof Coating||$79.00 (4.75 gal.)||1.25 – 2.0 gallons per 100 sq. ft.||For metal, smooth or mineral surface roll roofing, SBS and APP modified roofing, and evaporative coolers|
|Roof-Tec||Siliconized and Microcell Elastomeric White Roof Coating||$24.98 (1 gal.)||80-100 sq. ft. per gallon||Standing Seam and Corrugated Metal Roof, Concrete Roofs, Asphalt Roofs, Previously Coated Polyurethane Foam Roofs|