View Single Post
 
Old 6/2/18, 11:04 PM
blee2 blee2 is offline
Certified Professional Inspector (CPI) ®
 
Join Date: May 2015
Location: Portland Oregon
Posts: 90
Default Re: Mystery Black Substance: Not Mold, need help !

That's thermal bridging from outside which makes that area a little colder and it will condense water vapor which collects dust, ash and debris.
Reply With Quote