[Greenbuilding] Which insulation? How to install?

[RT]

On Sun, 27 May 2012 15:05:21 -0400, Eli Talking  
<elitalking at rockbridge.net> wrote:

> I was planning on the addition being built over grade slab,but one day  
> my contractor client got so enthusiastic with
> her excavator that she assumed a crawlspace and excavated accordingly.   
> It will be a crawlspace.

Rather than futz with all of the challenges/headaches associated with a  
wood-frame floor, I'd tend to stick with the original plan to utilise a  
slab as floor, but elevating it to the top of the stem wall foundation now  
that a hole has been dug.

It could be a suspended slab if it is desired to utilise the volume  
beneath. One option to accomplish this would be to make it a composite  
slab. There are pre-formed ribbed sheet metal pans which enable free-spans  
of 15 feet using only a 3-inch topping (ie 5" overall thickness including  
2" depth of the pan) but one could forego the cost of the pans and do a  
slab of about the same thickness by inserting a beam.

The simplest would be to just fill up the crawlspace with a load or two of  
stone, leaving enough room for insulation  (EPS rather than XPS would be  
fine in this situation) and then cast the slab on top.

If one prefers to minimise the use of high embodied-energy cement and  
concrete, there's no reason an earthen floor (or hybrid variation thereof)  
couldn't replace the concrete in the second option.

And contrary to AA-Man's preferences stated recently in another thread (ie  
cork it) , I think that a heavy mass floor is more beneficial from a  
thermal perspective and pragmatically superior to a wood-framed one.


-- 
=== * ===											AOD257
Rob Tom
Kanata, Ontario, Canada

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