One of the most popular choices in roof coatings are actually roof sealants. These materials are designed to address specific needs, including the type of roof, the conditions to which they are subjected, and they can provide weatherproofing and reflectivity. Knowing what kinds of roof coatings are available is an important part of determining which option will work best for your situation. The following are some of the most widely used roof sealants.
Roof coating manufacturers have been creating polyurethane-based sealants since the early 1960s, and they have certainly come a long way since that time. These sealants are available in systems that use one and two part moisture-cure and oxygen-cure processes. These roof coatings are most popular for use with EPDM membranes, especially in areas around flashing, coping, pitch pans, and termination bars, as they provide a water resistant seal. Urethane sealants range in price, but the lower end options tend to have very poor resistance to UV exposure. Additionally, they cannot stand up to anything other than very minimal dampness at the time of application, as the added moisture results in outgassing. When this occurs, the expansion and frothing that occurs results in extensive damage to the coating.
Silicone is another popular option for roof coatings, and there is a wide range of formulations. There are acetoxy-cure formulations, which are generally the cheapest, and the more expensive oxime-cure formulations. Acetoxy roof sealants can’t be used on metal surfaces due to corrosion, but they do resist discoloring due to UV exposure. Oxime-cure silicones work well with metals, provide better adhesion, and resist weather, but they do tend to discolor after UV exposure. These roof coatings are not a good option for areas that have substrates that release heat and oil, as this tends to loosen adhesion.
Polysulfide Roof Sealants
Polysulfide sealants have a long history of use, and they are elastomeric in nature. They tend to be more expensive than other options, but they provide excellent resistance to weather exposure, allowing for a long life of around 20 years before cracking occurs. This sealant will generally need to be applied over primed surfaces, and it has longer curing periods.
Polyether roof coatings are moisture-cure, and provide increased durability over some of the other roof sealants available. These sealants have a good rate of adhesion, and can be applied in colder temperatures without compromising the material. They provide good weather resistance, are environmentally friendly, and are highly OSHA complaint. They are easy to apply, fast curing, and typically last for 20 to 30 years when applied properly.
When it comes to choosing the right roof coating manufacturer, your best option is to make sure to compare products. Some of these sealants are better for certain jobs than others are, and making sure to understand the best applications will improve the life of whichever roof coating you choose. By paying close attention to the choices, you will be able to choose the material that best meets your needs.