June, 2006

Subject: Polyurethane Foam Fireblock vs. Traditional Fireblock Caulks.

Polyurethane foam sealants are used extensively for a variety of gap filling, air sealing and adhesive applications because of the many advantages that this product provides. One such application that is gaining in popularity throughout the U.S. is the use of expanding polyurethane foam for "Fireblocking" in Type V residential construction.

The use of PU foam in this application has been extensively tested and evaluated by ICC-ES (International Code Council Evaluation Services), and is recognized as an alternative to the methods prescribed by the code for maintaining the integrity of penetrations of fireblocking. While it is true that polyurethane foam is an organic material, and therefore will burn when subjected to the appropriate fire conditions, it has been shown through laboratory testing, including ASTM E 814, as required and modified by ICC-ES, that the polyurethane foam will perform equivalently, at least, to the other prescribed fireblocking methods. Furthermore, when PU foam is burned, it will not give off any more toxic gasses than would be given off by other organic building materials (such as wood, paper, etc.).

Technically, one of the intended purposes of a Fireblock material is to block the spread of smoke, and for this purpose polyurethane foam is an excellent material. However, one of the ironies of some of the older building codes and practices is that the use of "non-combustible" materials was called for, and most of these non-combustible products (usually sold in caulk/sausage tubes) are rock-hard materials which may, in fact, be less effective over time at stopping the spread of smoke as the one component polyurethane foams. Therefore, both the IBC and IRC (in Section R602.8) have eliminated the "noncombustible" requirements pertaining to fireblocks, and are revised to read "approved material to resist the free passage of flame and the products of combustion". (Although no code states this, reason would dictate that in combustible construction it is not logical to require noncombustible fireblocking materials on items that penetrate a wood plate drilled to provide a tight fit).

Handi-Foam Fireblock is covered under ICC-ES Report Number ESR-1868. Fomo Products, Inc. is a member of the FLM Group of companies, the world's largest manufacturer of one and two-component polyurethane foam systems in pressurized containers. For additional information, visit
www.fomo.com. 

This information is provided as a service, and is not necessarily meant to reflect any recommendation, guideline or position of Fomo Products, Inc. Each individual user must determine product suitability for any particular purpose.