Whether or not an intumescent coating, or even a thermal or ignition barrier, is needed often depends on the type of spray foaminsulation that builders use. Many closed cell foam sprays are already sufficiently fire resistant and need no additional barriers. Ultimately, whether or not you need an ignition barrier or thermal barrier varies depending on location and materials. You should check with your local code official to ensure that your insulation work is up to code. Spray Coating E/M Coating Services has over 40 years of experience in applying critical tolerance coatings, and is a pioneer in the development and application of solid film lubricant (SFL) coatings. With its network of five U.S. facilities, E/M Coating Services is the largest applicator of solid film lubricant coatings in North America. Additional facilities in Evesham, U.K.; Unna, Germany and Tianjin & Suzhou, China apply a broad range of SFL and other coatings to steel, titanium and aluminum substrates.
As this example illustrates, it's important to seal the envelope completely. One of spray foam's biggest selling points is its air-sealing ability, but it can't seal places where it's not sprayed. One of the nice things about using spray foam in new construction is that you can do a Blower Door test before the drywall goes in. Even better, you can test for leaks with a fog machine. Spray Coating