Spray Foam Insulation Chicago, Spray Foam Insulation Illinois

 Spray foam insulation fact and fiction

Fiction: Closed-cell spray foam insulation installed to the underside of wood roof decks will rot the deck because roof leaks go undetected due to the water resistance of the foam.
Fact: Closed-cell spray foam insulation has been installed to the underside of roof decks for more than 40 years with great results.  This is no historical record of SPF installed to the underside of wood decking causing deterioration from roof leaks. To the contrary, closed-cell spray foam insulation is water resistant and will repel liquid water.  It seals cracks and crevices in the wood deck so any water that gets past the roofing system stays on top of the wood deck and gravity takes it down to the edge of the building and off the roof. In colder climates, the SPF keeps the roof deck cold, so that ice damming is less likely to occur, further reducing the chance of water damage to the building.
Fiction: Closed-cell spray foam insulation is vapor retarder and cannot be used in warm, humid climates because it does not allow water vapor to go into and out of an assembly.
Fact: Closed-cell spray foam insulation has a perm rating of approximately 1.5 per inch to 3 per inch and an R-value of approximately 6 per inch.  This combination allows a controlled moisture vapor flow while separating the inside and outside temperature.  The result is better control of condensation within the building envelope, so long as there is sufficient SPF insulation to prevent condensation.  In most applications a half-inch to 1 inch of SPF will suffice in warm and mixed climates and 1 inch to 2 ½ inches in colder climates.
Fiction: lf the wood is wet when closed-cell spray foam insulation is installed, it will not allow the wood to dry.
Fact: The SPF industry, just like the painting industry recommends installing spray foam insulation to relatively dry substrates. But research has been conducted on installing SPF to wet lumber. D.M. Onysko and S.K. Jones reported in the Journal of Thermal Insulation 1992 that closed-cell spray foam will slow down the drying of wet lumber, but the lumber eventually dries with no deteriorating effects under typical building conditions and with the air-sealing qualities of the wall intact. Onysko and Jones did report that if closed-cell spray foam is installed to the cold side of a wall with a constant thermal gradient (which would cause a moisture drive always in one direction, such as cold storage facilities or extreme north climates), drying may be slowed sufficiently to cause wood decay.

The SPF industry does not recommend spraying open- or closed-cell foam on wet or damp surfaces because the spray foam adhesion will be affected.  Similar to painting, substrates to receive spray foam insulation of all types should be relatively dry wood (18 percent moisture content max). This can be checked very easily with a Delmhorst moisture probe. Installers know instantly if the wood surface is wet because the liquid reacts with the moisture, causing a color variation and poor rise of the foam.
Fiction: Spray foam insulation releases toxic gases such as formaldehyde, after it cures.  Closed-cell foam blowing agents contribute to poor indoor air quality.
Fact: SPF docs not and never has had formaldehyde in its formulas. Additionally, there is no evidence to suggest that polyurethane foam of any type contributes to poor indoor air quality by releasing toxic gases to the building.  Indoor air quality-testing of spray foam insulation both closed-cell spray foam and open-cell spray foam indicate that soon after installation (within hours or days) monitoring equipment fails to detect emissions of any type.

The blowing agents used in closed-cell spray foam up until 2005 had slight ozone depleting characteristics, which of released for the foam, could damage the ozone layer in the upper atmosphere. It was replaced with non-ozone depleting blowing agents (such as Honeywell™ HFC 245fa) in 2005.  Neither blowing agents have ever been considered an indoor pollutant.  They are not considered a toxic chemical, do not have irritating odors or contribute to allergic conditions.

Download:  Fact and Fiction Article by Mason Knowles