FAQ

When it comes to wildfires, roofs, eaves, and exterior siding are the most vulnerable due to their prolonged exposure to the elements, specifically embers during wildfires.

Stucco doesn’t actually burn, however it has what’s called a spalling effect which causes the trapped oxygen within the porosity of the stucco to explode, thus leaving what is behind it (usually wood) to burn.

Fire ratings rank a material’s surface burning characteristics according to how fast flames spread and how much smoke they produce, according to ASTM (American Society for Testing and Materials). The most common test for determining a fire rating is the Test Method E-84, or the tunnel test, which measures how far and fast flames spread across the surface of a given sample material. The results are then classified into three flame spread rating (FSR) groups, Class A-C. Cement would be considered Class A with 0-25 FSR, and untreated oak plywood ranks at class C with 125-185 FSR.

Is there an Extended Class A Flame Spread Rating?

Yes, the test for Extended Class A Ratings are designated as E-2768.  Wood siding treated by Sun FireDefense earned an Extended Class A Flame Spread Rating from Guardian Fire Testing Laboratories (see report here).

Intumescent coatings, which passively help increase a building’s resistance to fire, and standard flame resistant paints, work differently when reacting to heat. When heated, solutions mixed with intumescent coating expand and harden on top of whatever material it is covering. Once activated, it hardens and renders the treated material, especially wood, unsalvageable and damaged. Alternatively, once activated by heat, standard fire resistant paint expands into the material it is covering, extinguishing fires by preventing oxygen from feeding the flames. Once the heat is removed, most paints contract to their original state without damage to the treated surfaces.

Intumescent coatings are also mostly used on commercial buildings. The solution is more expensive and requires more product per application as it needs a 15-20 ML thick coating to be effective vs. 3-5 ML with standard fire resistant paints. Sun FireDefense’s paint solutions will also typically last through several extreme heat and fire events, whereas once intumescent coatings are activated, they need to be reapplied.

Treating a 5000 sqft home with fire resistant paint would take approximately 3 – 5 days depending on the prep work required to mask windows and cover shrubs and plants. 

Standard paints work best on wood, stucco, and fiberglass siding; plus, wood and composite roof shingles. These materials have porous qualities that allow the paint to expand into whatever it is coating to block oxygen to the substrates and extinguish flames.