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Is this a type of mold, efflorscence? Please Help!

Is this a type of mold, efflorscence? Please Help!


  #1  
Old 08-19-16, 02:12 PM
C
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Is this a type of mold, efflorscence? Please Help!

Hey guys,

So I started renovating the basement in my house. It is a very dry and mold free basement with no water or leakage problems whatsoever. About two weeks ago I got an egress window cut out in the concrete foundation and around the same time I started insulating the concrete basement walls with rigid foam insulation. About a week ago I noticed on the floor in the basement just in few spots where the window an accumulation of some sort of weird looking stuff, its not wet, and it is very fragile when you touch it, it almost feels like tiny tiny crystal fibers from bat insulation (picture attached). Could someone please advise what this might be? I vacuumed it in, but the next day or so it started to appear again, and it is only in a spot beside a wall few feet in length. I should also mention that it started to appear after I had an open cut out without any window for a few days while I was waiting for a window installation company.

I would appreciate any input on this, I need to resolve it before I commence framing. Thank you.
 
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  #2  
Old 08-19-16, 04:52 PM
B
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It would be a total guess from the picture, but efflorescence is a possibility.

For background, there is almost always moisture vapor passing through your concrete floors and walls. They may look dry, but only because the moisture vapoe is passing directly into the air.

Besides the cut for the window, what else has changed?

Bud
 
  #3  
Old 08-22-16, 08:31 AM
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Nothing have changed, asides from adding more rigid foam insulation up against concrete extrerior wall. Though, I have looked at different pictures and description on google, and it looks very much like efflorescence.

Thanks.
 
  #4  
Old 08-22-16, 08:46 AM
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When you added rigid insulation against the foundation walls it may have changed the path that the moisture was following. Even though some rigid foam board will have a small amount of permeability it is still a vapor retarder. If that green is your rigid foam, check its perm rating and if it is coated with a plastic or foil film.

Bud
 
 

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