FLAME AND SMOKE RATING

PESTAN pipe systems do not produce toxic byproducts during a fully developed fire. PP-R(CT) are similar to other natural combustible materials, like wood and paper, in that they can produce trace amounts of CO in an under developed fire. PESTAN adheres to local code requirements that focus on the volume and opacity of the smoke. Such codes require a flame spread index of 25 or less and smoke development index of 50 or less. Requirements can be referenced in codes ASTM E84 in the United States and CAN/ULC S-102.2 in Canada. Pipe insulation is considered fire rated material because, according to the IMC and UMC building codes, they are not exposed within the plenum. PESTAN recommends the following solutions for applications to meet the required FSI of 25 and SDI of 50:

  • The pipe should be encased in insulation that meets the 25/50 flame spread and smoke development index. Subject to IMC codes, UMC codes and local authorities, the fittings should be insulated or the pipe can be enclosed in a fire-rated chase.
  • Use ducted or dedicated outdoor air instead of ceiling return air plenums. Return air plenums pose health and safety risks as well as requiring large amounts of fire-retardant chemicals be used. Flame spread and smoke development requirements are generally irrelevant to pipes outside a return air plenum.

These options should help the engineer comply with local flame spread and smoke development codes.

Using the I-Codes

Under the IMC, materials exposed within plenums are required to meet the ASTM E 84 test for flame spread and smoke development. As given in the 2006 edition:

602.2.1 Materials exposed within plenums. Except as required by Sections 602.2.1.1 through 602.2.1.5, materials within plenums shall be noncombustible or shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 50 when tested in accordance with ASTME 84

Exceptions:

5. Combustible materials enclosed in noncombustible raceways or enclosures, approved gypsum board assemblies or enclosed in materials listed and labeled for such application.

Exception 5 excluded materials that were enclosed within noncombustible (or otherwise approved) materials, as the enclosed materials are technically concealed, rather than exposed. This exception was further detailed in the 2012 edition, making the intent of the previous editions expressly clear:

602.2.1 Materials exposed within plenums. Except as required by Sections 602.2.1.1 through 602.2.1.5, materials within plenums shall be noncombustible or shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 50 when tested in accordance with ASTM E 84 or UL 723

Exceptions:

5. Combustible materials fully enclosed within one of the following:

5.1 Continuous noncombustible raceways or enclosures

5.2 Approved gypsum board assemblies

5.3 Materials listed and labeled for installation within a plenum.

If pipe and fittings are enclosed in the insulation that abide by ASTM E 84 requirements, PESTAN pipe may be installed in the plenum because insulated pipes are no longer exposed inside the plenum. Plenum-rated wraps would be an adequate alternative where insulation is not needed.

Using the IAPMO codes

The UMC contains similar requirements to the IMC in regards to plenums. In turn, the exceptions are similar, although the UMC does not offer as detailed of an exception. In the 2009 edition, it reads:

602.2 Combustibles within Ducts or Plenums Materials exposed within ducts or plenums shall be noncombustible or shall have a flame spread index not greater than twenty five (25) and a smoke developed index not greater than fifty (50), when tested as a composite product in accordance with one of the following test methods: NFPA 255, Method of Test of Surface Burning Characteristics of Building Materials, ASTM E 84, Surface Burning Characteristics of Building Materials, or UL 723, Test for Surface Burning Characteristics of Building Materials except as indicated below.

Exposed materials must meet flame spread and smoke development requirements or be non-combustible. IMC intends for unexposed materials in the plenum to be excluded from this requirement.

In the 2012 edition the associated test methods are simplified but maintain this language.

602.2 Combustibles within Ducts or Plenums Materials exposed within ducts or plenums shall be noncombustible or shall have a flame spread index not greater than twenty five (25) and a smoke developed index not greater than fifty (50), when tested as a composite product in accordance with ASTM E 84 or UL 723, except as indicated below.

Consequently, as long as the pipe remains excluded from the plenum space, PESTAN pipe may be installed. This may be achieved by enclosing the pipe and fittings in a plenum-rated insulation, or plenum-rated wrap where insulation is not required.

If you are in need of additional options that were not addressed above, please contact Pestan Engineering Support department in Titusville, PA via email Engineering@PestanPipes.com  or by phone 1-800-486-7473.