Elastomeric coatings are a common and popular type of coating for commercial roofing systems. These coatings are similar to rubber, and most types are water-based. Elastomerics can be applied to many different sloped, slanted and flat commercial roofing types and protect roof materials in San Antonio, TX, from thermal heat damage. Most elastomeric coatings are applied in at least two coats, and a third coat is recommended in certain circumstances.
Butyl elastomeric roof coatings are liquid sealants. They work well over flat, metal, and single-ply membrane roofing systems. The sealant protects your roof from the elements and lengthens the roof’s functional lifetime.
Isobutylene was first discovered in 1825 and it was developed into butyl rubber by 1937. Butyl rubber is a synthetic rubber, or elastomer. It is very flexible and impermeable to air. Common uses of butyl rubber include solvents, adhesives, fiber optics, fuel additives, sports equipment and window insulation.
Butyl elastomeric commercial roofing coatings adhere securely to many types of substrates, including metal, modified bitumen, built-up roofing, concrete, polyurethane foam, concrete and single-ply TPO, PVC or EPDM. The coating forms a seamless, waterproof membrane that is very flexible. This synthetic rubber sealant stretches during high temperatures and maintains its original shape in cold weather. These properties let butyl sealants resist cracking and shrinkage.
A sealing coat can be applied to the entire commercial roofing system and joints. Butyl coatings reflect UV rays to prevent roof degradation and reduce or prevent further leaking and degradation of weathered roofs. Some butyl coatings contain pesticides and mildewcides.
Perhaps the most recognizable type of acrylic plastic is Plexiglass. It is often used for bullet-proof windows due to its high impact resistance. Plexiglas is an all-acrylic material, but most acrylics are produced to blend with other materials. Blended acrylics are used to make numerous products, such as paint, caulk and adhesives. The greatest advantage of acrylic polymers is their versatility.
Acrylic polymers are formulated to possess various qualities for specific purposes. Some acrylic polymers are tough, hard and flexible, while others are elastic and flexible with a high tolerance of low temperatures. Acrylic polymers capable of waterborne emulsion were developed in the mid-1950s. This development led to acrylic latex house paint. Waterborne acrylic paint is extremely durable, and it is now one of the most commonly used types of house paint.
Acrylic polymers designed for roofing coats are applied as a liquid with a brush or spray mechanism. The liquid polymers form a tough, durable and seamless membrane that fully adheres to roof substrates. Acrylic elastomeric roof coatings reflect UV-rays, resist ponding, retain flexibility at low temperatures, and expand or contract without cracking.
These properties help coatings stand up to thermal expansion in San Antonio, TX, and seismic expansion caused by snow or rain. Commercial roofing coatings also need to withstand regular foot traffic due to routine tasks such as servicing HVAC units, maintaining satellite dish antennas, and caring for other types of equipment related to specific businesses. Acrylic polymers do not absorb ultraviolet radiation, and acrylic coatings contain UV blocking pigments to protect roof substrate as well. Most acrylic coatings are white and reflect up to 85% of sunlight to reduce roof temperatures and minimize heat transfer to the building.
Polyurethane roof coatings, also known as urethane coatings, are some of the most durable and rugged of all elastomeric coatings. They adhere strongly to numerous roofing substrates including modified bitumen, single-ply, EPDM, smooth and gravel BUR, concrete roof decks. Some polyurethane coatings are used for sprayed-in-place polyurethane foam insulation. Polyurethane coatings are resistant to ponding and extremely flexible to withstand thermal expansion and contraction. They are also exceptionally impact-resistant compared to many other coating types, so they are often used on roofs with high-traffic areas.
Polyurethane coatings are categorized as aliphatic or aromatic. Aliphatic coatings are UV stable and highly reflective, so they are very useful for preserving colors. These properties also reduce heat transfer during summer months and reduce coolings costs. Aliphatics are normally applied as a top coat due to UV stability and their ability to resist dirt. Aromatic coatings are less UV stable and usually function as base coats.
There are also several disadvantages of polyurethane commercial roofing coatings, which explain why polyurethane is not universally used despite many strongly positive characteristics. Polyurethane produces a strong, unpleasant xylene-based odor. The vapor is not dangerous, but it is pervasive and most people strongly dislike the smell. Buildings with fresh air intake HVAC systems should take precautions before and immediately after polyurethane coating application. Set the system to recirculate air within the building or turn the system off completely until the coating has finished drying.
Polyurethane coatings are also solvent-based, which causes difficulty during application. The urethane liquid wears out hydraulic spray equipment quickly and leads to frequent repairs. The spray equipment must be carefully cleaned and maintained during and after use. Single-component urethane coating liquids are constantly curing, even in the original product container. Plural-component urethane does not start curing until it is mixed.
Silicone commercial roofing coatings contain more solid components than most coatings, so they are usually applied in a single coat. Silicone is one of the easiest types of coating to apply. These coatings dry quickly and they can be applied regardless of outdoor temperatures. Silicone-based coatings are solvent-free with very minimal VOC levels.
One positive aspect of silicone coatings is also a negative in some circumstances. Silicone repels most dirt and liquids. This will keep your roof nice and clean, which is especially helpful in high-traffic areas, but other things you may want to apply are not going to stick either. For example, spray foam will not adhere to silicone. You would need to remove the silicone layer and reapply it afterwards to add spray foam.
Contact Longhorn Commercial Roofing in San Antonio, TX, with any commercial roofing questions and inquiries concerning roof coatings. The skilled technicians at Longhorn can offer advice on protecting your building’s roof.
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