Handi-Foam® E84 Class 1 Two-Component Polyurethane Foam is one of a family of fire-rated products available from Fomo Products, Inc. This Technical Bulletin serves to clarify the various issues relating to the use of Class 1 foam in construction practices.
ASTM E84, “Standard Test Method for Surface Burning Characteristics of Building Materials,” is a widely recognized standard used to classify the surface burning behavior of building materials such as insulation, paneling, flooring, etc. A summary of this test method, which is also sometimes referred to as “UL 723” or the “Steiner Tunnel Test,” is described below. Most of the major building codes in the United States reference ASTM E84, which rates a product for its “Flame Spread” and “Smoke Development.”
Note: These numerical flame-spread ratings are not meant to represent a time rating and are not intended to reflect performance under actual fire conditions (see below for further information about what these ratings mean).
ASTM E84 is a large-scale fire test that involves exposing a sample of the foam that is 24 feet long and two feet wide to an open flame at one end. The Flame Spread number is a calculation, not a direct measurement, which takes into account the time of ignition, rate and extent of burn, and is a comparison of the tested material relative to a totally noncombustible material (e.g., inorganic cement with a Flame Spread of zero and untreated red oak, which has a defined Flame Spread of 100). As indicated above, the Flame Spread is not a time rating. A photovoltaic eye measures smoke density and the number value should be equal to or less than 450 for a Class 1 designation. This smoke number is a direct measurement.
The term “Class 1” refers to a material that exhibits a Flame Spread of 25 or less and a Smoke Development of 450 or less, when tested according to ASTM E84. The term “Class 2” refers to a material that exhibits a Flame Spread of 75 or less and a Smoke Development of 450 or less. Most residential building codes require all insulation (regardless of whether it is a Class 1 or 2 polyurethane foam or faced fiberglass insulation bats) to be covered by a 15-minute “thermal barrier,” such as drywall, between the wall insulation and any habitable living space. In traditional nonhabitable areas or locations within a building (e.g., sill plates, attic eaves, crawl spaces, etc.), it is up to the local building official (the “Authority Having Jurisdiction”) to decide whether a thermal barrier is required directly over the insulation.
Handi-Foam E84 Class 1 meets the above mentioned criteria for a “Class 1 Foam.” Other fire-rated products available from Fomo may be tested according to other defined small-scale fire tests, depending on the intended application of the product. For example, Silent Seal Two-Component Mine Ventilation Sealant is tested according to the specific small-scale and/or large-scale fire tests that are mandated by the Authority Having Jurisdiction for underground mining (i.e., MSHA).
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.