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Mould????


doitnewf's Avatar
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12-08-03, 11:06 AM   #1  
doitnewf
Mould????

I am going to insulate my basement concrete walls with 1.5" styrofoam sheets.
I had the sheets layed in place for the past couple of weeks.
I removed one of the sheets & noticed that the concrete wall in the corner was a little black.
Whats causing this?

Cheers
JP

 
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12-08-03, 03:11 PM   #2  
It is likely mildew from moisture and lack of evaporation due to being trapped under the styrofoam sheet.

 
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12-09-03, 04:02 AM   #3  
doitnewf
Will vapour barrier over the insulation stop this?
I finishing the wall with drywall, and want to make sure I do it correctly.
Thx
JP

 
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12-09-03, 06:36 AM   #4  
If there is enough moisture in the basement to cause mildew to form on the stored sheets, resolving the moisture problem is in order.

Tape a sheet of plastic wrap to the wall. After 24 hours check for condensation under the plastic. If present, this indicates that there is too much moisture for you to proceed as planned.

Trapping a contiuing supply of moisture under an impermeable barrier such as styrofoam will encourage its growth. Over time the mildew will degrade both the styrofoam and the basement wall.

Eliminating moisture from a basement includes directing downspouts away from the house, grading around the house to direct water away from the house, perimeter drainage along the lines of footing drains or french drains to move water away, and sealing the exterior of the basement walls to prevent the entry of moisture into the walls to start. It may be that a dehumidifier would help, but keeping the moisture out initially is more important. In any event, a dehumidifier won't help if the styrofoam is applied over the moist walls.

Hope this helps.

 
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