Walkout basement insulation cover

Old 02-07-18, 05:25 AM
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Walkout basement insulation cover

Nearly 1/2 of my basement wall is non-masonary walkout (above ground with wood stud construction under vinyl siding) and is uninsulated. I'm looking to insulate that area in order to moderate the basement temperature and improve the temperature in the rooms above it. I have no desire to use the basement for living space.

Although my basement is quite dry, I am concerned about moisture and mold/mildew issues which often occur when insulating basements with fiberglass.

Using XPS is not workable because of the total cost of this large area so my approach is to insulate with unfaced fiberglass rolls and cover the area with a transparent vapor barrior which will allow me to monitor the insulation for mold or mildew. Using faced insulation is less desireable because my understanding is sheetrock would be required (for fire protection) which will stop me from monitoring the insulation.

So, my questions are:
  • Is anything wrong with my approach?
  • Can a vapor barrier provide adequate mold/mildew protection to fiberglass insulation in a non-masonary walkout wall?
  • Is sheetrock or a similar cover required when using faced insulation and not for unfaced?
  • Is there another cost efficient option?
Old 02-07-18, 08:56 AM
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I am concerned about moisture and mold/mildew issues which often occur when insulating basements with fiberglass.

Mosture/mold and fiberglass have no direct correlation. If you have a moisture issue then you can get mold regardless of the type of insulation.

The problem arises when a vapor blocker (plastic) is used which traps water vapor within the wall causing moisture and providing a an environment for mold to grow.

I personally do not use, or need foam attached to my walls, it's expensive and if the walls are constructed properly it is unnecessary.

Build your walls, use faced or un faced insulation but give sufficient space behind the wall for air circulation. Insulate above the wall but leave spaces open so air (and moisture) can circulate.

Yes you are leaving small areas open but the other 98% of insulated walls will make a huge difference.

I have a daylight basement and with no insulation the basement was in the mid 50's, after finishing it's now in the mid 60's.

Fiberglass should be covered, drywall is good. In the back area of my basement is my work shop, I covered with Tyvek!
Old 02-08-18, 11:06 AM
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Roxul or other mineral wool would be my choice.

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