Mer-ko by Westcoat has received IAPMO Class A and 1 Hour Fire Rating

Posted in News  |  September 21, 2017

Outdoor deck

We are excited to announce that Mer-ko by Westcoat has received Class A and 1 Hour Fire Rating IAPMO Listings. These listings will replace the former expired ICC listings for Shur Deck (#3200) and Weather Deck (#2009). The Uniform Evaluation Report ER-517, for Mer-Ko by Westcoat, was issued on July 27, 2017. Both of the Mer-ko systems Mer-ko Shur Deck and Mer-ko Weather Deck systems received the Class A and 1 Hour fire ratings. These systems were evaluated for use as the walking deck (Div 07 18 13) and roof covering systems (Div 07 50 00). As of December 8, 2017, the listing also includes supplements for California (meets 2016/2013 California Building / Residential Code) and City of Los Angeles (meets 2017 LABC / LARC code). You can find the full listing here on the Mer-ko site.

What is a Class A Fire Rating?

A Class A Fire rating is when a combustible material is put through a performance test and has been indexed by a numeric value less than 25 for the flame spread. Most commercial wood species have a flame spread index between 90 and 160 (Forest Products Laboratory, 1999).

What is a 1 Hour Fire Rating?

A “one-hour” fire rating is given to various building materials that can resist the exposure of a standardized fire for one hour. The rating was created to evaluate the performance of building elements, such as walls, floor, or roof systems during fire exposure. The test follows standard procedures that specify the rate at which the temperature increases over the course of the test.

Interested in learning more about our systems?

Please contact Robert Ryan our Sales representative who can answer your waterproofing questions, he can be reached at or via our Contact Us page.