Replies

1. 
   JohnT8 | Feb 04, 2005 07:31am | #1

   Scamp, you're gonna run into people with different preferences...  So let me be the first to voice my two cents worth.

   If properly done, ICF's are quite capable of doing the job... however if the price was the same, I would rather have a regular poured wall and then apply the insulation to it later.    Probably just my old fashion nature, but the old fashion forms are tried and true technology and you're going to find more contractors who know how to use them.  Additionally, with form-made walls, you can apply waterproofing to the concrete prior to insulating.

   The insulation debate flares up from time to time.  The ICF balances insulation on exterior/interior of wall.  If you're using regular form-made poured walls, you can choose to put all the insulation on one side.

   Interior side insulation:  On the plus side, you have a wide variety of insulation types you can use.  Probably the first one I'd think of using would be EPS (expanded polystyrene... white styrofoam..similar to styrofoam cups).  Standard EPS can't be placed below grade on exteriors, but it can be used on the interior. 

   On the down side of interior insulation...  You're losing floor space. You are also losing the thermal advantage of the concrete wall.  Also, if finishing the space you will need to drywall/plaster it.

   Exterior side insulation: From an energy efficiency point of view, I think this is the way to go.   By having all your insulation on the exterior, you are able to employ the massive concrete wall as a thermal flywheel.  Basically like having a big thermal battery.  Concrete doesn't insulate well, but it does hold heat.  This means less cycling of the heating system in that space. It holds its temperature better.  Also, if you have a good texture on the concrete, you can use it as the finished wall.

   On the down side, you're just about stuck using XPS (extruded poly styrene.. blue/pink board), which tends to be more expensive than EPS.  Also, you need to have some form of anti-bug plan in place.  While insects dont eat the insulation, they have been known to like the easy construction material it provides.  Some insulation manufacturers include borax into the mix to discourage bugs.  Also, XPS should not be exposed to extended sun exposure.  It will eventually break down (so bury/cover it).

   Side note: There are some EPS manufactures who are producing specially modified EPS which is supposed to be capable of being used below grade on exteriors.  An example is r-control  http://www.rcontrol.com .  Mike Smith has used this company and seems to have a high opinion.  I've never used it, but Mike's recommendation is good enough for me.

    

   jt8

   Our lives improve only when we take chances -- and the first and most difficult risk we can take is to be honest with ourselves. -- Walter Anderson

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   Edited 2/3/2005 11:33 pm ET by JohnT8

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   Edited 2/3/2005 11:34 pm ET by JohnT8

   
   

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   Edited 2/3/2005 11:36 pm ET by JohnT8

2. 
   JohnT8 | Feb 05, 2005 01:17am | #2

   Scamp, post this question in heating/insulation and you'll get a bigger response.

    

   jt8

   Our lives improve only when we take chances -- and the first and most difficult risk we can take is to be honest with ourselves. -- Walter Anderson

1. 
   scampernatra | Feb 05, 2005 02:06am | #3

   Thanks for the info. I must have hit the wrong prompt because I couldn't find this discussion over in heating,venting,insulation thread. I'll resubmit it over there.

   Edited 2/4/2005 6:08 pm ET by SCAMPERNATRA