Basement Insulation - so many different opinions

Old 11-17-01, 08:19 AM
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Question Basement Insulation - so many different opinions

Which is a better insulator for a basement? Ridge Foam or Fiberglass? RF doesn't have very high R values. FG, I've heard, will cause mold and mildew.

I live in northern NJ, my basement is not wet, and I run a medium sized dehumidifier that I have to empty every three days. There is already a frame of furring strips, because paneling was once up.

Please help with question. Thanks.
Old 11-17-01, 11:27 PM
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You're right, there are probably a dozen different opinions on this. Some things to consider:

1. 3-1/2" of fiberglass has an R-value of 11 to 13; white beadboard has an R of about 4 per inch; blue Styrofoam brand rigid has an R of 5 per inch and rigid polyisocyanurate has an R of 7 per inch(don't quote me on the iso; going by memory!).

2. If you're going to put electrical in the walls, 3-1/2" of fiberglass is a lot easier.

3. I think fiberglass with studs will be cheaper.

Be sure to put in a vapor barrier. Also, in my area, they require an additional moisture barrier directly against to block. To avoid the problem of the double vapor barrier, the moisture barrier is stopped somewhere near the top of the block so any moisture can escape at the rim joists. This whole thing moisture barrier thing makes me very nervous, but it's code in my city. I can't be sued for complying with code if something goes wrong can I??!!

Hope this helped.

Old 11-18-01, 02:27 AM
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Basement insulation

There have been some good posts on this forum recently in regard to insulation. You might want to click the Search button and type in: basement insulation. You might also find informative and helpful.
Old 11-20-01, 01:47 PM
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If you are already pulling that much water out of the air in this area, then installing fiberglass (FG)would probably be a disaster because FG has a nasty habit of suspending water which drastictly reduces the insulation value and also provides a warm moist home for mildew and mold. Under best of conditions FG is only about 10% efficient.

Foam can also provide a home for mold and mildew. It is only about 20% efficient.

As you have probably heard on TV and the newapaper, insurance companies are fighting home oweners over the payment of damage to house and personal body due to mold/mildew problems.

I use radiant barrier material in basement installtions because it is 97% efficient and will work in 1x2 furring strips. It is a superior vapor barrier and will not cause mold/mildew to form. You should also remove any FG from the joist/rimboard area to stop condensation, dryrot and any possible mold/mildew and replace it with radiant barrier material.

The material you would use is a kraft paper base with aluminum foil lamenated to both sides. It will last as long as the house.

For more radiant barrier info, enter your search engine; "radiant barrier" or "reflective insulation".

If you have any questions or are have trouble finding this material, let me know.

Thank you for considering my opinion.

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