Closed-Cell Spray Foam Pulling Away from Foundation Walls in Crawlspace
We are currently building a new custom home in upstate NY (zone 6) with open-cell spray foam insulation above grade and closed-cell in the crawlspace.
The installation in the crawlspace was done on two separate occasions because the first time it was only R14 when R23 is called in the spec so the crew needed to come back and add an additional layer.
During the installation in late April, the condition in the crawlspace was cold (48F) and humid, wet foundation walls to a point mold had formed in certain areas – relative humidity at 98% (measured by a hygrometer). There was also sitting water (a puddle) from earlier in the process that was never fully drained through the foundation drain.
After the spray foam installation, everything seemed fine until it got warmer outside and a dehumidifier was installed by the crew. Recently, we noticed the insulation coming off the foundation walls at the base around the perimeter of the foundation. See photos. The relative humidity is now at ~45% w/ 70F with the dehumidifier running non-stop. The house is still under construction but in the final phases.
Has anyone ever seen this and can reflect on the severity of this issue and to what extent it compromises the insulation properties?
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