There are TWO basic types of Fireproofing used in Construction. Sprayed Fire-Resistive Materials (SFRM) and Thin-Film Intumescent Fire-Resistive Materials (TFIFRM), they can be applied to steel components such as columns, joists, beams and decking. These materials encapsulate, or coat the structural steel components to protect from fire damage.
There are two common types of SFRM: Cementitious and Sprayed Mineral Fiber’s. Cementitious fireproofing is made from Portland Cement or Gypsum Plaster. Both types are mixed with water and sprayed into place, forming a uniform, monolithic finish. Sprayed mineral fiber is blown onto the component through a hose, forming a thick coating that is fluffy in appearance. Both of these SFRMs are designed to be hidden behind interior or exterior finishes, such as drywall, precast panels and false ceilings.
Photos shows both types of products, 1. Cafco Blaze shield2 (Mineral Fiber). 2 Monokote MK-6HY (Gyosum Plaster)
TFIFRM is a water or solvent-based thin film of intumescent paint. It is typically applied by spraying and is virtually invisible. In the intense heat of a blaze, this film will soften up and expand to form a thick meringue-like layer that insulates the steel for a period of time, generally up to two hours. Intumescent coatings allows the engineers and architects to design their buildings with exposed structural steel, while still maintaining the level of fire protection that is required. It is also beneficial because the coating can be colored to match the surrounding architectural elements
When a contractor is using approved fireproofing materials, it is also important to have the materials inspected and tested to meet or exceed manufactures recommendations. Observation and Inspection confirms that the product was applied within the tolerance level specified in the contract documents and product specifications.
Inspection and Material Testing of the SFRM consists of thickness measurements, density testing and cohesion/adhesion tests.
Thickness Testing is determined by inserting a penetrating pin through the SFRM to the substrate. The higher the hour rating requirement is for a structural component, the thicker the SFRM should be. (Photo attached shows Engineers Thickness Requirements at different locations within the building and a standard thickness gauge).
Density Testing of the SFRM consists of removing a known volume of SFRM from a structural component and drying the material to a constant weight to determine the weight per volume. This is typically done in a laboratory setting. (Photo shows material being sampled for testing from a identified beam).
Cohesion and Adhesion Testing. This test is performed to determine the bond strength of the SFRM to the steel component. A plastic cap with a hook in the center is bonded to the SFRM, then using an force is applied until the SFRM has a cohesion or adhesion failure or until the product specifications are met. Fireproofing adhesion and cohesion kits that meet ASTM E736 (shown Below) can be purchase for accurate material sampling. The simple pull gauge records the actual fail point in lbs./ft.
Inspections and testing performed for the TFIFRM consists of Wet or Dry Thickness Measurements.
Dry thickness measurements are performed utilizing coating thickness gauge (shown below) that measures the non-magnetic coating applied to Columns, Beams and Decking.
Wet thickness measurements are performed using a wet paint gauge.
Association of the Wall and Ceiling Industry | AWCI.
AWCI, Technical Manual 12A and 12B.
AWCI link is attached below for more Information and Standards.