[Strawbale] Soil gas (was Re: Cold rooms)

[Rob Tom]

On Thu, 19 Apr 2007 21:04:51 -0400, Chicken Little wrote:

> On Thu, 19 Apr 2007 07:13:21 -0400, kim thompson  
> <shipharbour at ns.sympatico.ca> wrote:
>
>> compacted earth floor in a
>> large(about 1500 sq') unheated basement
>>
>> The client is looking at installation of :
>> a leveling sand base on basically bedrock
>> -> then a 6 ml poly vapouur barrier

> I wouldn't be comfortable with the sand layer beneath the poly/earthen  
> floor and would prefer that washed stone be used instead and that stone  
> within the footings provided with drainage tile (that is either drained  
> to daylight or a dry well) to ensure that any water that gets in, gets  
> out.

Something that I wanted to mention last night before I got distracted by  
the hockey game and before I forget now...

If the site is exposed bedrock and that rock is anything like the rock  
here in Kanata (ie Canadian Shield) then radon ay be an issue.

[ Aside: There is a subdivision down the road from me about which an urban  
legend circulates about the subdivision having been built on top of a  
nuclear waste dump site, a myth further exacerbated by the fact that there  
was an Atomic Energy of Canada Limited (now re-badged with no mention of  
"atomic" anythere in the name) R&D facility next door and a small defunct  
landfill on the site. I'm guessing that homeowners were doing radon kit  
tests and getting spooky results. In any case, the reality is that the  
site was all rock and the developer spent a winter dynamiting the rock  
apart and then dynamiting the dynamited rock into smaller chunks in order  
to bulldoze the site flat before trucking in mountains of dirt to cover  
the blasted rock chunks and then subdividing it into parcels to sell to  
developers.]

If in fact radon may be an issue at the Nova Scotia site, then the stone  
layer beneath the poly moisture/soil gas barrier would facilitate soil gas  
collection (better than damp sand) and that gas could then be safely  
exhausted rather than having it find its way into the basement.

-- 
=== * ===
Rob Tom
Kanata, Ontario, Canada
< A r c h i L o g i c  at   C h a f f Y a h o o  dot  C a  >
(winnow the chaff from my edress in your reply)