Hi everyone, I could use some guidance.

I’ve been dealing with serious indoor air quality issues in my custom-built home since day one. The house is two years old, and from the first month, I noticed chemical and musty odors. We’ve already undergone extensive mold remediation inside the walls.

Now I’ve discovered that the open-cell spray foam insulation on the attic roof decking also has issues. The foam ranges from 5 to 12 inches thick, and in many areas over 100 sq foot that has been uncovered, there is 2–3 inches of brown staining where the foam contacts the OSB roof sheathing. These areas have strong odors, and lab tests have confirmed the presence of Stachybotrys and Aspergillus mold.

I’ve been in a 2 year-long dispute with the builder and subcontractors. Based on what we’re finding, I may need to remove all spray foam (about 10,000 sq ft), the OSB, and roofing materials.

My Questions:

1. If you had to remediate and re-insulate an attic like this (foam, OSB, and roof  being removed), what approach would you take?

2. If you were not planning to live in the home again and planned to sell it after remediation, what insulation and construction method would you use that balances code compliance, resale value, and cost-effectiveness?

I’d really appreciate insight from anyone who’s dealt with similar situations or professionals in building science, insulation, or real estate.