Fireproofing, a passive fire protection measure, refers to the act of making materials or structures more resistant to fire, or to those materials themselves, or the act of applying such materials. Applying a certified fireproofing system to certain structures allows these to have a fire-resistance rating. The term fireproof does not necessarily mean that an item cannot ever burn: It relates to measured performance under specific conditions of testing and evaluation. Fireproofing does not allow treated items to be entirely unaffected by any fire, as conventional materials are not immune to the effects of fire at a sufficient intensity and/or duration.
INTUMESCENT – Epoxy based fireproofing that helps with CUF that is applied direct to substrate which prevents air gaps between fireproofing & substrate. An intumescent is a substance that swells as a result of heat exposure, thus increasing in volume and decreasing in density. Intumescents are typically used in passive fire protection and, in the U.S., require listing and approval use and compliance in their installed configurations in order to comply with the law.
These intumescents produce a light char, which is a poor conductor of heat, thus retarding heat transfer. Typically, these materials contain a significant amount of hydrates. As the hydrates are spent, water vapor is released, which has a cooling effect. Once the water is spent, the insulation characteristics of the char that remains can slow down heat transfer from the exposed side to the unexposed side of an assembly. Soft char producers are typically used in thin film intumescents for fireproofing structural steel as well as in firestop pillows. Typically, the expansion pressure that is created for these products is very low, because the soft carbonaceous char has little substance, which is beneficial if the aim is to produce a layer of insulation.
Harder chars are produced with sodium silicates and graphite. These products are suitable for use in plastic pipe firestops as well as exterior steel fireproofing. In those applications, it is necessary to produce a more substantial char capable of exerting quantifiable expansion pressure. In the case of firestops, a melting, burning plastic pipe must be squeezed together and shut so that there will be no opening for fire to propagate to an otherwise fire-resistance rated wall or floor assembly. In the case of exterior fireproofing, a hydrocarbon fire must be held off with quite potentially more kinetic energy than a house fire. Intumescents that produce hard chars are unsuitable for interior spray fireproofing.
CEMENTITIOUS – Removal, repairs, & sealing of fireproofing
Cementitious fireproofing as defined by UL refers to the manner in which the material is pumped. Cementitious fireproofing products (Portland/gypsum) are pumped like concrete in slurry with air added at the nozzle to convey it onto the steel. It has absolutely nothing to do with product ingredients.
Cementitious products provide long term durability, high bond strength, excellent air erosion and overall superior performance.