Coatings for Flat Roofs: A Guide to The Different Roofing Materials

Roofing contractors of Napa, California, share the basics of roof coatings as a solution for roof leaks.
What Types of Roof Coatings are Best for Flat Roofs?
Though roofs are most often sloped, especially in the realm of residential roofing contractors, flat roofs have become a staple of commercial roofing and multiple-family housing, such as apartment buildings and the like. This extra square footage can be worth a great deal when space is at a premium in crowded city areas. Unlike sloped roofs, flat roofs can be used to expand usable space, but they have common problems with water pooling.
Preventing this water from making its way into the structure is important to roof functioning. Flat roof coatings can help.
There are five main types of roof coatings that help preserve the integrity of flat roofs, and we will discuss the advantages and disadvantages of each one.
An Overview of Roof Coatings
Roof coatings are a protective shield that can actually serve to prevent roof replacement. Some coatings wear down and need to be redone regularly. Others are a more permanent solution. Coatings add protection against the elements such as dirt, UV rays, and water or ice. This equals better energy efficiency and extends the life of the flat roof. As previously stated, there are five main types of coatings. They are:
- Acrylic
- Polyurethane
- Silicone
- Spray foam
- Thermoplastic
Just as not every roof is the same, not all coatings are either. They serve slightly different functions and need different preparation and training for installation.
Acrylic Roof Coatings
These environmentally-friendly, water-based roof coatings are inexpensive and easy to apply. The high reflectivity of the coating promotes energy efficiency and protects against UV light damage. It can be used on almost any roofing material. Though the versatility and price point make it attractive to many buyers, acrylic coatings often crack in a few years and need regular reapplication in order to maintain full coverage.
Polyurethane Roof Coatings
Polyurethane is a common product in construction due to its resistance to physical damage. In roofing, it is known for its ability to hold up against water and heavy foot traffic, which makes it a good choice for flat roofs that are frequently used and walked on. There are two main types of polyurethane coating: aromatic and aliphatic polyurethane.
- Aromatic: This polyurethane coating is less stable against the ravages of UV rays, but it is less expensive.
- Aliphatic: This coating is more stable but also more expensive.
These coatings can be affected by moisture when they are applied, so the roofing company must be careful about when the coating is applied.
Silicone Roof Coatings
Silicone is a widely used material in everything from hair products to baking to roofing. This material requires certain special prep when installing, and only a qualified roofer should install it. It is expensive, but because silicone is an inert material (that is, it does not respond to chemical corrosion or reactions), it is incredibly durable and maintains its ability to reflect UV rays throughout its life. It has a very long lifespan and doesn’t degrade with long exposure to the pooling water that is common on flat roofing, butit does tend to attract dirt and can become slippery in wet conditions.
Spray Foam Roof Coatings
This product is a form of polyurethane and is used for both insulation and roof coatings. While this does provide an excellent waterproof and insulating surface, there are several particulars to be aware of when dealing with spray foam. It requires a protective top coat to protect against UV rays and physical damage. It requires qualified professional installation.
Thermoplastic Roof Coatings
This is perhaps the most durable and complicated form of roof coating. Qualified roofers with heat welding equipment are required for this particular type of coating. There are several different roofing types that will fall under the heading of thermoplastic coating. The most notable of which are PVC and TPO. PVC stands for Polyvinyl Chloride, and TPO stands for Thermoplastic Olefin. Once installed they require very little roofing maintenance and are quite durable, making them perfect for commercial roofing.
Other Roof Coatings
There are a couple of other roof coating types that are worth mentioning. Bitumen or asphaltic coating is one type that uses materials similar to those used in traditional asphalt shingles that are the most common roofing material for traditional sloped roofs.
Another roof coating is EPDM coating or ethylene propylene diene monomer. This is specifically used with EPDM rubber roofing. These roofing materials are used in specific situations.
Choosing the Right Roof Coating
Choosing a roof coating is not as easy as picking a new coat off the rack and putting it on. If the roof is older, it must first be determined whether or not roofing repair or roofing replacement is required. Some roof leaks can be prevented through coatings, but if a leak has already happened, roof leak repair needs to happen first to prevent mold and mildew from setting in.
After an initial roof inspection, a reputable roofer will be able to recommend what the next steps are. If the roof is ready for coating, then several things need to be considered. The climate or the general weather in the area must be analyzed using the coating that will work best. Lots of sun or lots of rain might put certain coatings lower on the preference list. Another thing to consider is the roofing material and whether or not it is compatible with a particular coating. The method of application and maintenance requirements should also be a part of making the final decision.
It is also important to find a reliable roofing contractor to do the roof coating for such an integral part of the building. Incorrect installation could be devastating to the structure and interior of a building. Find a roofer with a good reputation and years of experience in the business. Roof coatings can seriously extend the life of the flat roof, but need to be installed by a trained and experienced roofing contractor.
About Modern Method Roofing
With more than 60 years of experience, Modern Method Roofing offers not only years of experience but also 100% financing and senior discounts. Call today for a free estimate in Napa, California, and the surrounding areas.
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