Thermal barriers come in the form of 1/2-inch gypsum drywall or any material that is proven to have an equal fire resistance to gypsum wallboard. Additionally, alternate assemblies can be used if they have been tested in a laboratory and approved. Ignition barriers are a lower standard to meet, and can be satisfied with a number of different materials. Like thermal barriers, they can be substituted with equivalent fire resistant materials and alternate assemblies, such as an intumescent coating.
There have been a few mentions of intumescent coatingsabove, and it would be helpful to elaborate on them. Intumescent coating is a type of paint that will bubble when it is exposed to heat or flames. The bubbles act as a barrier that is relatively flame resistant. The bubbled coating delays the ignition of the spray foaminsulation. Because of this, intumescent coatings have become more common in building and construction.
With all good DIY projects, you need to start with quality products to get the job done right. Krylon spray paints can cover anything from plastic and metal to cement and more. Use Krylon blue spray paint, Krylon green spray paint or Krylon yellow spray paint in a stained-glass finish to make a new table centerpiece. Krylon red spray paint, Krylon purple spray paint and Krylon orange spray paint can revitalize old patio décor into a vibrant outdoor space. Breathe new life into patio planters with Krylon brown spray paint. It’s easy to stay on trend with Krylon pink spray paint or get creative with Krylon metallic spray paint. With all these colors, the possibilities are endless. For projects that need just the basics, Krylon white spray paint, Krylon black spray paint and Krylon gray spray paint can help you tackle any job.
Ignition barriers include six permissible materials. An ignition barrier can be 1/4-inch plywood or structural panels, 1 1/2-inch mineral fiber insulation, 1/4 inch hardboard, corrosion resistant steel at least .016 inches thick, 3/8-inch gypsum board, or 3/8- inch particle board. These sizes are the minimum; code officials will approve of thicker versions of any of these six materials as ignition barriers. Like thermal barriers, equivalent materials that have been shown to have equivalent fire resistance are acceptable. Additionally, an alternate assembly can be used if the assembly has been tested by a laboratory and meets certain criteria. Insulation Spray Coating

Spray foam is available in two different types: open-cell spray foam which is usually $0.44 to $0.65 per board foot and closed-cell spray foam which is about $1 to $1.50 per board foot. The average cost to have spray foam professionally installed is about $2,347. This number can vary depending on whether the home being insulated is newly constructed. However, finished homes are not a good candidate for spray foam insulation but great for weatherization or an energy audit.  
Building code regulations typically call for the use of thermal barriers when spray polyurethane foam is installed. The code requires that the foam is separated from any living spaces by a layer of 1/2-inch drywall. As discussed earlier, any material that has been approved as being as equally fire resistant as the gypsum drywall can be substituted as a thermal barrier. Spray Coating