If you have a foam roof on top of your business, then you should know that this type of roof requires maintenance and the occasional repair like any other roofing material. If you notice bubbles on your flat roof, then it is time for some serious maintenance to be performed. Keep reading to understand how these bubbles form and how you can go about repairing them.

Why Do Bubbles Form?

Bubbles across your foam roof will look like small or large rounded domes that stick up from the surface. These bubbles are often referred to as blisters and they are a sign that moisture has reached the inner layers of the polyurethane material. Foam roofs are made from spray foam polyurethane by mixing two different materials together. These materials are called isocyanate and polyol and the finished product is similar to the spray foam used for home and business insulation. The roofing material is a closed-cell foam. This means that air bubbles are locked into the foam, and moisture can gather in these open areas. Moisture will need to work through the elastomeric coating that sits on top of the foam first. This coating is typically a rubberized sealer that is acrylic-based. 

The elastomeric coating that sits over the polyurethane will wear away over time and need replacement. Recoating will generally need to occur about every five to ten years. If you allow the sealer to wear away without replacing it, then it will thin. Moisture will end up in the air pockets and the pockets will expand to create the blisters. This means that blisters need to be repaired and the entire surface of the roof will need to be sealed. A roofing contractor should be contacted to add the sealer, but you can repair the blisters first. 

How Do You Repair Blistered Areas?

Before you begin making your repairs, identify all of the blisters across the roof. You will need to remove the damaged areas with a razor knife and fill them in with polyurethane caulking material. Use the knife to gentle scrape away the sealer over the top of the blister. Use the knife to pop the blister and feel inside with your finger. If the area feels wet, then use your knife to cut a square around the blister that is about one-half inch larger than the blister on all sides. Use a putty knife to pry up the blister. Inspect the damaged area for any moisture and continue cutting away damaged foam until only strong and dry foam remains.

Use your polyurethane caulk to fill in the opening where the blister was removed. The polyurethane will need to cure before you seal the repair. It can take up to 10 days for the curing process to complete, so wait about 10 days for the material to dry completely. If you seal the caulk before it has had a chance to dry fully, the material may form its own blister due to the trapping of moisture against the foam. 

After you wait 10 days, you should cover the repair with acrylic elastomeric roofing sealer. You can purchase this material from your local home store. Use a roller to apply the sealer. While this is the same type of sealer that your roofing contractor will use to seal the roof, it is not wise to cover all the foam at this time. Sprayers are typically used to create a thick and level surface. Also, the roof will be cleaned thoroughly first. If the coating is secured over a dirty surface, it can pull away from the foam and possibly peel away from the roof.

If you currently have a foam roof and you notice protrusions or blisters, then you should consider fixing your roof fairly quickly. For more insight or assistance, contact services like Specialty Commercial Contractors LLC.

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