Foam questions

[AHI in AR]

I came across this insulation in a house today which was built in 2006. The insulation was used on the back side of the second-story walls common to the attic as well as on the ceilings exposed to the attic. It was also used on the foundation stem walls above the concrete block. It looks like icynene, but because it is extremely rare here I don't know for sure. In 14 years of doing inspections here this is the first home I've seen with this product. My questions concern appropriate thickness and whether there are any known problems with this. It was not sprayed on the underside of the roof deck. What is the R value per inch? It was only about 4 inches thick on the ceilings on average, and the thickness varied significantly.

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[Marc]

SPF. Spray Polyurethane Foam.

R value/inch varies with density of the product.

Marc

[Tom Raymond]

It looks like closed cell. The applicator was fairly inexperienced, ccSPF is never smooth but it should not be that lumpy. It might even be DIY from a froth pack.

ccSPF is generally between R-4 and R-6 per inch depending on density. For that application average the depth to get an idea of R-value.

The area in your pic would be considered accessible and should be coated with an ignition barrier. There are several coatings that can be painted on, or it can be covered with drywall.

Are water heaters routinely installed in unconditioned space in your area?

[AHI in AR]

Thanks for the info guys. I just couldn't see that 4" was adequate on the ceilings.

Yes, Tom, water heaters are routinely installed in attics. It just doesn't get that cold or stay cold here for long. In the summer tank-types barely have to run since the attics stay so hot!

[JEuriech]

Low density, open cell SPF weighs between 0.4 to 0.6 lbs per cubic ft when fully cured. The SPF has an R-value around 3.5 per inch.

Closed cell SPF weighs between 1.5 to 2 lbs per cubic ft when fully cured. The SPF has an R-value of around 6.0 per inch (aged R-value)

See some of the following web sites for more information:

http://www.sprayfoam.org/

http://www.sprayfoam.com/

Jeff Euriech

Arizona Prime Property Inspection LLC