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howard.wheaton · 10-19-2008, 06:57 PM

Does anyone know anything about the Reflectix insulation. It is a double layer of trapped air bubbles between foil facings. I am looking to install insulation on the walls of my crawl space and just saw this at Menards. I will leaning towards the fiberglass, but then you have the issue of mildew if it gets wet.
Thanks

Wildie · 10-19-2008, 07:45 PM

I insulated my crawl space with ROXUL insulation.
Its made from melted rock that is spun and formed into bats.
Fibreglass is usually rated at R12 per 3 1/2". Roxul is R13.
The advantage of Roxul is that doesn't absorb moisture and has a fire rating!

i fastened mine to the masonry with pins that are glued onto the wall.

Here's a link! http://www.roxul.com/sw34086.asp

Winchester · 10-20-2008, 12:05 PM

Foamboard was reccomended to me by our energy auditor.

Illinois recommends an R-Value of 25 in crawl spaces.

In my readings, crawl space walls are only insulated if the crawl space is unvented and the floor above the crawl space is uninsulated.

jerryh3 · 10-20-2008, 12:16 PM

Quote:

Originally Posted by Winchester

Foamboard was reccomended to me by our energy auditor.

Illinois recommends an R-Value of 25 in crawl spaces.

In my readings, crawl space walls are only insulated if the crawl space is unvented and the floor above the crawl space is uninsulated.

Was R-25 recommended for the floor or for the crawlspace walls?

Winchester · 10-20-2008, 07:40 PM

Quote:

Originally Posted by jerryh3

Was R-25 recommended for the floor or for the crawlspace walls?

That would be walls as per the OP original intentions.

jerryh3 · 10-21-2008, 06:37 AM

Quote:

Originally Posted by Winchester

That would be walls as per the OP original intentions.

Just asking because R-25 seems high for a crawlspace wall.

Wildie · 10-21-2008, 05:19 PM

Quote:

Originally Posted by jerryh3

Just asking because R-25 seems high for a crawlspace wall.

If you have enough space, the more insulation the better. The question being whether its cost effective.
In northern areas wall framing is now standardized at 5 1/2 in. to allow for additional insulation. (R20).
R25 would only be a couple more inches, and the extra cost payback would be quick!

jerryh3 · 10-21-2008, 06:15 PM

Quote:

Originally Posted by Wildie

If you have enough space, the more insulation the better. The question being whether its cost effective.
In northern areas wall framing is now standardized at 5 1/2 in. to allow for additional insulation. (R20).
R25 would only be a couple more inches, and the extra cost payback would be quick!

Where are you that walls are standardized to 5.5?

Wildie · 10-21-2008, 07:25 PM

Quote:

Originally Posted by jerryh3

Where are you that walls are standardized to 5.5?

What are known as 2X6's are really 1 1/2 X 5 1/2 in size.
I'm in Canada and its considered wise to use 2X6 wall studs to allow for extra insulation.
I do assume that the northern US states would do so, also!

It would likely be a good idea to use them in the south to reduce cooling costs, also.

jerryh3 · 10-21-2008, 07:54 PM

Quote:

Originally Posted by Wildie

What are known as 2X6's are really 1 1/2 X 5 1/2 in size.
I'm in Canada and its considered wise to use 2X6 wall studs to allow for extra insulation.
I do assume that the northern US states would do so, also!

It would likely be a good idea to use them in the south to reduce cooling costs, also.

Oh. That north. I agree about the 2X6's.