Risks Associated with Poor Spray-Foam Installations


‘Leathery’ spray foam has lost it’s air pockets and is no longer effective. Is it inert in this condition?

A few months ago, I posed a question about spray foam installations and wet wood to some of the forums I belong to.

I got an astounding response — some of it snarky, most of it super helpful. I’m still editing a longer piece that will cover the responses, but in the meantime I ran into this:

Squishy, deflated, leathery 2lb foam. This was installed on the leaky concrete wall of a basement stairwell with a partial foundation, with a connection to an unflashed framed wall above. The house was built in 1836, while the stairwell was obviously a much later addition. The foundation is very wet, the tidelines on the mechanical equipment hitting the 8″ mark, and obvious water markings on the exposed part of the original rubble foundation. After reading all the comments from my original question about spray foam installations and the considered responses, I have to ask myself what spray foam contractor worth their salt would install in such conditions?

The water damage is easily seen throughout the rubble basement walls. The insulation was sprayed onto the top 24 to 36″ of the rubble wall, but has lots of voids and cracks. There is also a wide range of spray consistencies visible — some of the foam looks positively cumulous, while other parts look like smooth lava. Rookie installer? D-I-Y install from a kit system? Who knows — the homeowners purchased this spring and have no records.

From a cursory walk around the perimeter of the house, I knew there would be one fixable source of water leakage into the foundation: over the 175 years, the grade had settled (dramatically in some places), and snow melt and rain water were caught and funneled down into the rubble wall. Straightforward solution to that cause: regrade. Other problems with the foundation, not so straightforward, but we’ll see.


Water is getting through the spray foam…that’s a crappy installation with all those of voids.

The state of this spray foam made me wonder about health issues, because it had so obviously perished and was dripping this ghastly caramel coloured ooze. There is some field research being done to look at the risks associated with installing spray foam (Field Research to Provide Deeper Look at Spray-Foam Risks – BuildingGreen), but I am not familiar with any studies published on long-term health risks to occupants as a result of crap installations like this one. There are substantiated issues with offgassing immediately after installation, yes, but let’s assume that the product performs as its data sheet indicates, and 24 hours sees most of the offgassing dissipate in a properly done installation.

Water penetration in walls is a problem, period, regardless of the type of insulation that is used, so I’m not freaking out on one type of insulation. From many, many problematic basements, we know what is likely to happen in below-grade frame wall cavities filled with fiberglass batt insulation. When the fiberglass gets wet, it doesn’t drain well or dry out and so causes mold growth given enough warmth. That causes health problems. Cellulose is a total no-go below grade for the same reason. As far as I’m concerned, rockwool is the best option for fibrous insulation below grade. Or spray foam. But only once the foundation is dry. There are so many indoor air quality and eventual structural problems that can be minimized or eliminated by eliminating water leakage into the foundation, and so many that can become exponentially worse by NOT eliminating water leakage into the foundation.