The technical name for Spray Applied Fireproofing is Sprayed Fire-Resistive Material (SFRM). It is used as part of a building’s passive fireproofing strategy. Spray applied fireproofing has thermal and acoustical properties and controls condensation. Spray applied fireproofing is primarily used to protect rigid structural elements including columns, beams, metal decking, and some steel joists from the effects of heat generated during a fire.
SFRM is composed of cement or gypsum and often contains other materials like mineral wool, quartz, perlite, or vermiculite. The gypsum or cement makes up the majority of the solution and is selected because it hardens as it dries. The other materials are used to help lighten the solution or to add air as in insulator. Chemical hardeners are sometimes used to either speed up hardening or to make the final fireproofing harder than normal. Passive fire protection products, such as fireproofing, is used to delay (or even prevent) the failure of steel and concrete structures that are exposed to the high temperatures found during a fire. They do this by thermally insulating the structural members to keep them below the temperatures that cause failure.
There are three key properties of SFRMs: density, bond strength, and application thickness.
Traditionally SFRMs have been divided into three distinct density product groups:
Low, standard, or commercial density contain gypsum as the binder. Low density SFRMs often provide higher yields and have faster coverage rates when compared with medium density products, which can reduce cost.
Medium density generally contains a binder made from cement or a mixture of gypsum and cement. This provides a much more stable product that can withstand air movement and minor bumps and scrapes.
High density usually made with a cement binder, which provides the hardest fireproofing product. High density is usually used in mechanical rooms and parking garages since it can withstand bumps and scrapes better than the lower densities.