I have been dealing with a spray foam nightmare for several years now. I had closed cell foam installed in my crawl space and rim joists by a contractor who later revealed himself to be an unprofessional scam artist. The foam did not cure properly as there continued to be a lingering sweet smell months after the install. With good ventilation and as the weather cooled, the smell dissipated.

It came back the next spring so I called the contractor to have him come inspect and remove it. He ultimately stopped responding to my calls and took his webpage down. I made a major mistake in not vetting him and not having a formal contract, and now have no way of tracking him down.

I ended up removing as much of the foam as I could myself but there are still some spots behind duct work and crevices of the joists that I cannot fully access without tearing ducts and joists out. The smell has significantly improved and is not noticeable at all for most of the year, and I have never smelled it in the living areas of the home.

Unfortunately the smell came back this May as the temps heated up. I’m able to manage it by venting air out through an air scrubber. I’m planning to try to remove even more of the stuff and tear out ducts if needed to get the last of it. I’m worried that there may be a forever lingering smell even if I take it all out though, as the off gassing has likely infiltrated the wood.

My question is, would an ERV be worth exploring to aid in continual ventilation and bringing in of fresh air? I am in Maryland so I think ERV is more appropriate than HRV for the summer months. I’ve read that VOCs may not be fully vented out as they can transfer from the outlet to inlet within the ERV core, do you know if this would be the same for isocyanates? And if we did go the ERV route, would it be best to have air drawn out of the basement directly rather than from the HVAC system?

My house was built in 1927 so is definitely not airtight. My family all deal with indoor and outdoor allergies, so the possible improvement in IAQ is promising. Thanks for any guidance you have.