Why does it take more than one coat of roof coating to properly seal a commercial roof?

Good question. It is difficult, if not impossible to spray one coat evenly on your commercial roof. When you apply just one coat of roof coating you invite too much risk that some areas will be too thin. Since a chain is only as strong as its weakest link, most roof coating manufacturers recommend 2 coats be applied to a commercial roof. Also, if a roof coating is applied too thick in some instances it will sag before it dries or result in other defects. If you’ve ever painted a wall and applied the finish too thick you will see this with either tiny bubbles or even “mud cracking” in some circumstances.