Specification History

SWS Version Created Specification ID Title Specification Objective Supporting Materials Rationale Status
Version 2025 09/24/2023 - 17:16 4.0402.1b Material selection

Select insulation that:

has a flame spread/smoke development index of 25/450 or less when tested in accordance with ASTM E 84 or UL 723

is, or include a facing that is, a class II vapor retarder

is not water absorbent

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Select fire safe and hydrophobic materials

, basic_html		 Regardless of Appendix A which doesn't specify where the insulation types are to be installed, this is about preventing moist air from moving from inside a conditioned space to the exterior surface and condensing. Previously, the committees debated whether or not any drying to the inside was desirable and determined the answer was no. The other specs mentioned in the justification are relating to conditioned basements, which typically have more connection to the main body of the house, and are better conditioned. Red Line
Version 2025 09/24/2023 - 17:16 4.0402.1b Material selection

Select insulation that:

has a flame spread/smoke development index of 25/450 or less when tested in accordance with ASTM E 84 or UL 723

is, or include a facing that is, a class II vapor retarder

is not water absorbent

Select fire safe and moisture resistant materials

 Regardless of Appendix A which doesn't specify where the insulation types are to be installed, this is about preventing moist air from moving from inside a conditioned space to the exterior surface and condensing. Previously, the committees debated whether or not any drying to the inside was desirable and determined the answer was no. The other specs mentioned in the justification are relating to conditioned basements, which typically have more connection to the main body of the house, and are better conditioned. Red Line
Version 2020 08/14/2020 - 14:25 4.0402.1b Material selection

Select insulation that:

has a flame spread/smoke development index of 25/450 or less when tested in accordance with ASTM E 84 or UL 723

is, or include a facing that is, a class II vapor retarder

is non-absorbent

Select fire safe and moisture resistant materials

 Black Line
Version 2020 08/14/2020 - 14:25 4.0402.1b Material selection

Select insulation that:

has a flame spread/smoke development index of 25/450 or less when tested in accordance with ASTM E 84 or UL 723

is, or include a facing that is, a class II vapor retarder

is non-absorbent

Select fire safe and moisture resistant materials

 Black Line