# Yes, Another Basement Insulation Question



## gregzoll (Dec 25, 2006)

Or just go with Sprayfoam and forgive the combo batt & foam board.


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## Beepster (Oct 19, 2009)

Do you think that would be more cost effective than either of the options I have mentioned?

I may use this procedure to seal up the rim joists once all the mechanical, electrical, and plumbling have been done...depending on price. 

B


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## gregzoll (Dec 25, 2006)

In the long term, yes.


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## High Gear (Nov 30, 2009)

1" foam and R 13 here.

I believe BS says to keep humidity levels below 50% with this combo.

I did the 2" XPS at the sill band , doubled up for 4" to = R20

The basement is considerably warmer without opening any heat ducts even, no regrets.


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## Beepster (Oct 19, 2009)

High Gear said:


> 1" foam and R 13 here.
> 
> I believe BS says to keep humidity levels below 50% with this combo.
> 
> ...


After you doubled up to 4" did you then 2 x 4 stick frame? I like to have the framing for the electric, DVW, and water supply. Heating ducts are no problem as the main trunk runs overhead of the bedroom bathroom and utility room on one side of the load bearing wall and is next to the living room on the other side.

I want to do this properly w/o overkill ($$$).

B


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## High Gear (Nov 30, 2009)

The framing is 2x4 up tight against the 1" xps , so R5 foam + R13 glass.

Sill joist band area only was 4" of xps.

Lots of threads on this using the search feature.

Sure its overkill but I want my comfort in the winter.

Main floor 72f , basement 66.5f ( with basement heating ducts closed) 

outside 37.6f gotta luv those remote temp moniters.


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## Beepster (Oct 19, 2009)

Sorry High Gear, I misunderstood, what you have done sounds exactly what I want to do. I thought you had 4" of XPS all the way down the wall.

I want to have a 1" poly board and unfaced insulation in the framing(R5 + R13). I was asking if 1" of poly instead of 2" will create a moisture problem on the inside of the board (condensation). I will monitor the humidity levels in the summer to see if I need a humidifier.

B


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