# Limited space for foam board behind built in cabinets



## gregzoll (Dec 25, 2006)

How are those cabinets attached to the wall? You are going to have to take the cabinets away from that wall to properly do the work.


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## jjeglbs (Nov 20, 2010)

There are actually 5 cabinet units on top of a common base. I have been able to remove the units from the base, though, so I have access to the wall before I put them back. They were attached to the base and on the ends with a few nails into the walls on the side.


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## Ron6519 (Mar 28, 2007)

Considering your climate, why not frame out the basement and install the recommended thickness of insulation for your locale?


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## gregzoll (Dec 25, 2006)

Ron6519 said:


> Considering your climate, why not frame out the basement and install the recommended thickness of insulation for your locale?


In mine and the OP area, which we would have the same Winter & Summer temps pretty much. They would need minimum of 1" XPS, then a bottom plate of pre-treated 2x4 or 2x6, with at least a 1/2" airgap, then the Drywall (Green or Purple Board is recommended in our area, because there are a lot of old mines, which causes high water tables.

The biggest issue is that they first have to coat the walls with Ugly Drylock, before anything can go up.

I went the simple route. When we had our house resided, we brought the siding with an insulating backer installed 2" off of the ground, to allow the basement not to be affected as much as it was before without it.

You find a lot of homes in Central, IL that are not finished, because of 100 year floods, which causes sewer backups, and with the fact of having the high water tables.


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## jjeglbs (Nov 20, 2010)

Framing out the basement would be ideal, but the width of the cabinets would prevent that (if I want to keep them all). I was just wondering if there are any less optimal solutions. The basement has only been covered in drywall and paneling to this point, and it is still comfortable. But, I am trying to improve efficiency to the extent possible.

We are on a hill so sewer back up is possible but hasn't happened around here. Drainage outside is very good.


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## gregzoll (Dec 25, 2006)

jjeglbs said:


> Framing out the basement would be ideal, but the width of the cabinets would prevent that (if I want to keep them all). I was just wondering if there are any less optimal solutions. The basement has only been covered in drywall and paneling to this point, and it is still comfortable. But, I am trying to improve efficiency to the extent possible.
> 
> We are on a hill so sewer back up is possible but hasn't happened around here. Drainage outside is very good.


No there is not. You may end up losing those cabinets, because you cannot leave the XPS exposed. It has to be covered with Drywall after hung.


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## jjeglbs (Nov 20, 2010)

Thanks for the responses gregzoll. That's what I was afraid of. So, do I need a certain thickness of XPS? Can I use the 1.5" InsulPink with 1/2" DenArmour (for a total of 2.25")? If so, maybe I can find a way to make it work, at least on the back of the cabinets.


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## jjeglbs (Nov 20, 2010)

OK, this might sound odd, but I'm trying to keep the cabinets and not put drywall behind them. What about 1/4" Durock? Would that be a sufficient cover over XPS?


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## gregzoll (Dec 25, 2006)

You still have to cover the XPS for all areas. I would not use Durock or DensShield, because they are made for tiling. I would just go with either Green Board or Purple Board. The Yellow board is fine, but not great when it comes to painting it. But it will hold up better if something gets banged into it.

You may be able to shave some off of the cabinets somewhere. I cannot see how the person that made them, made it one large unit, without building them in sections.

I am in Springfield and before I put in Central air & placed Foam board over my windows. The Basement was always hot and humid. I ended up having Griffitts Siding here in Springfield take the Al-Side siding down to within an inch or two from the ground, which has greatly helped with keeping the temps down there around 66. I have seen it get down to 62 at one point. Before the siding was installed, I could not get the basement below 69.

Now Owns Corning makes an all in one product for insulating Basement walls, which also includes a covering. But you are talking of losing about 4" The good thing with you finishing the downstairs, it will give you a blank template to keep taking it a step at a time to finish it. You may recover the costs if you ever decide to sell. Some times you do not. Especially those who put in Home Theaters.

But if you are wanting a Man Cave, or a place for kids to get out of your hair and on rainy days to go do something down there. Get it done and try to keep costs down.


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## Gary in WA (Mar 11, 2009)

Welcome to the forum!

Your location requires R-10 continuous on the interior blocks; http://energycode.pnl.gov/EnergyCodeReqs/index.jsp?state=Illinois

DensShield (not just for tiling) has a FG waterproof covering, not for your basement application. Green board; not here either; http://www.freepatentsonline.com/article/ASHRAE-Journal/169458047.html

Durock (not just for tile) cement board/purple board has a lower perm rating (>10) than regular drywall (58), but would still allow some restricted drying due to cabinets- much better to furr them out on top the drywall, for some air movement.

DryLock will slow/stop/redirect any moisture to the joint of slab/CMU to pool and gain entrance there. Also; http://neutocrete.com/what-is-drylock-and-does-it-work

To coat the whole wall I would want an interior drainage system in place. You could add some foil-faced foamboard only to the sections of block wall behind the cabinets with unfaced XPS on the rest. This would let any moisture through, safely throttled. 

The wood furring would need to be well attached; in-line with the cabinet attachment locations. Use foam-compatible adhesive on the FB, in a 1' grid pattern to limit interior air getting to the block to condense there. Insulate the wood rim joists with f-faced XPS to also stop summertime condensation there at R-10 with additional FG to total R-20 for exterior walls above grade requirements. Be sure to air seal under/over the rigid foamboard for complete air-seal.

Gary


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## jjeglbs (Nov 20, 2010)

Gary in WA said:


> You could add some foil-faced foamboard only to the sections of block wall behind the cabinets with unfaced XPS on the rest. This would let any moisture through, safely throttled.
> 
> Gary


Thanks for the detailed information Gary. So, do you mean put foil-faced foam board directly on the CMU and then the cabinets up to the f-faced foam (or maybe an air gap there)? In other words, does the f-face provide the needed thermal barrier? I will plan on achieving at R-10, even if it means somehow bring the cabinets out a bit.


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## Gary in WA (Mar 11, 2009)

I meant use Ffaced only where the moisture coming through the wall in springtime will condense on the cabinet backs (if using unfaced). Foil behind the upper/lower units with unfaced between them- top of countertop to lower edge of uppers- as a kitchen. Leaving this 16-18" gap in the impermeable barrier (foil faced) will let moisture through so you don't saturate the mudsill as the wall will be wet in winter, trying to dry to inside. Regular drywall for ignition barrier, otherwise check this with local AHJ.

Gary


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