# R-Value Thickness foam board in basement floors/walls



## alecmcmahon (Apr 30, 2010)

Getting around to finishing my basement, I had some water issues previously but solved them by installing an interior french drain ( weeping system ) in to my sump pump and new gutter system.

It's been about a 9-10 months since these were installed and my basement is nice and dry.

When it comes to insulation for the floors and walls i'd like to use rigid foam board. What thickness is recommended for the walls and floors? 

Due to space, and ceiling height i'd like to use the " bare minimum " 

Would 1" foam board under 1/2 plywood for the floors suffice? 

and 1" or 1.5" on glued to the walls with 2x4s in front with fiberglass insulation in between the studs work? 

Im in central NJ, east coast... temps range from about 10 degrees F to 110 degrees F

thanks


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## Gary in WA (Mar 11, 2009)

Find your Zone in the charts below the map: http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec001_par001.htm

Find the wall/slab insulation requirements with the zone here; http://publicecodes.citation.com/icod/irc/2009/icod_irc_2009_11_sec002.htm

Do you have any exterior below-grade rigid insulation existing?
Or under-slab insulation?

Gary


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## alecmcmahon (Apr 30, 2010)

No current isulation. House was built in 1955. Cinderblock walls


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## Gary in WA (Mar 11, 2009)

And what R-value is required for your location?

Gary


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## alecmcmahon (Apr 30, 2010)

Zone 4. Looks like r13?


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## Beepster (Oct 19, 2009)

What is your floor currently made up of? Concrete? 

What do you plan to use as flooring? Carpet? Tile? Wood?

B


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## alecmcmahon (Apr 30, 2010)

currently concrete.


PLANNING on 

1" ( or 1.5" ) rigid foam board

+

1/2" plywood

+

Laminate flooring


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