Vermiculite spray is a tough, hard and highly stable passive fire protection coating applied to structural steel members by spray application. It can be also applied by troweling, when necessary. It consists of factory produced blend of exfoliated vermiculite, cementitious binders and rheological and mix dispersing agents supplied as a dry mix to which clean water is added on site. It does not respond to any form of expansion, foaming or chemical reaction to impart its fire protection properties.
Available in 2 grades:
Internal Grade – robust, economic coating for internal use
External Grade – tough coating for external use, resistant to variety of climatic conditions
Both grades are designed for installation by spray techniques. It can be applied to bare steel surfaces in the thickness of up to 30 mm at a time. The surface of the steel should be dry and free of dirt, oil, loose mill scale, flaking paint and loose rust.
As applied, both grades of spray are rated “Non-combustible” to BS476 Part 4:1970 and comply with performance requirements of “Class O” as defined in Building Regulations.
Both grades have been fully tested on structural steel beams and columns for up to 4hours fire resistance in accordance with BS476 Part21: 1987.
The Thickness of the fire protection material required for a given period of fire resistant is dependent upon the surface area of the steel member exposed to fire and its equivalent cross sectional area (Hp/A) value for the section. Detailed information on the required thickness for SLV is available upon request.