[GSBN] health (ill) effects of earthen floors

[RT]

(from the GSBN List which Wild Bill-Bob recently made more accessible to  
the SB World so I won't bother providing the link to the GSBN List  
archives)

On Thur, 5 Jan 2012 11:49:48 -0700 Derek Roff <derek at unm.edu> wrote:
Re: health (ill) effects of earthen floors


> It is quite clear that contact with feces is the main problem
[snip]

Unlike the Derelict, I haven't been thorough enough to read the articles  
in question before commenting but that's never stopped me from yammering  
on before.

And due to an increasingly sieve-like memory, I can't recall the specifics  
of some missed-diagnosed soil-borne illnesses that were in the news here  
in Ontario within the past few months.

What I do remember though is that the missed diagnoses happened because  
such cases occur so rarely that it doesn't cross the minds of the doctors  
to check for that specific cause.

Unfortunately, I don't recall much about the matter but I do know that it  
is a bacterial infection that afflicts people who breathe air in the  
vicinity of a particular type of freshly excavated soil (no faecal matter  
involved) that has not seen daylight and the atmosphere for a long, long  
time.

In an attempt to find details to jog my memory, I did a quick Google using

      "missed diagnoses severe illness bacteria from soil"

and some of the hits returned were:

         - CLOSTRIDIUM DIFFICILE TOXIN (aka "C. difficile ")
	- acute bacterial meningitis
	- Legionella waltersii

... and so on -- all pretty scary buggers that can in severe cases, result  
in death of those afflicted.  ( I have vague recollections of perhaps  
having seen "bacterial meningitis"in relation to the Ontario news stories  
but I'll leave it to others with more of a stake in the issue to dig  
deeper).	

Me ? Despite Beel's best efforts, I never really became a big fan of  
earthen floors for my locale.

One :

Earthen floors make a lot of sense in places the climate is such that  
earth-coupling is a reasonable proposition. That is not the case in most,  
if not all of Canada.

In order to use an earthen floor in this climate, it would be necessary to  
de-couple it from the earth with at least R-20 worth of insulation  
(assuming that the floor is at or near grade)

It would also be necessary to provide an effective strategy to prevent  
soil-gas intrusion into the indoor air environment, something that is less  
of a concern in climates where air-tight construction/super-insulation is  
not essential.

The above almost relegate earthen floors to being not much more than a  
cosmetic veneer to provide a pastiche of "natural" earth-connectedness.


Two:
I was stunned by the volume of oil that Beel told me was needed to  
adequately "condition" soil mixes to rendered them serviceable as finished  
surfaces (by Auntie Septic's North American standards of performance).  I  
remember my Mom telling me that back in Olde China where human labour was  
cheap, the floor guys simply pounded the $#!+ out of the earth to compact  
it and called it a floor.

I found Beel's revelation to be disturbing given the horror stories about  
woodworkers' linseed-oil-soaked finishing rags spontaneously combusting  
... not to mention the potential for long-term pollution of interiors due  
to the plentiful VOCs  that such large volumes of oil would necessarily  
generate. Again, not so much of an issue in warmer climes where high air  
change rates would be okay.

Three:

Drying of the oil treatment. I've found that when treating timbers with  
linseed oil, it is best done during the heat of summer with the timbers  
outside in full sun and exposed to breezes. To do otherwise either results  
in insufficient depth of penetration of oil (ie not enough oil applied to  
do much good) ... or incomplete polymerisation of the oil resulting in a  
surface that remains tacky and prone to bleeding for a long, long time ...  
and over that period, being a magnet for air-borne crud and subsequent  
microbial activity within the accumulated crud -- not the stuff of healthy  
interiors, besides looking like hell.

I suspect that I could come up with several more numbers but I'll quit at  
Three.

There are of course the other high embodied-energy stabilisers like  
Portland cement and lime that one could use but given the mix ratios one  
would need in order for the stabilisers to be effective , one does wonder  
what an environmental impact analysis would reveal when compared to using  
the same amount of cement to make a concrete mix.

Given the much smaller particle size of an earthen floor mix, my guess is  
that the cement would be used more effectively (from a  
performance/durability perspective) in making a concrete mix.

Animal blood, faeces, plant starches all have their own issues too.

But one then wonders, why not forget about trying to make the earthen  
floor a finished surface  and thereby forego all of the sometimes-nasty  
stabilisers and simply use the earthen floor as a substrate for a  
baked-hard earthen mix (ie clay tile) or stone ?

An advantage of such finishes (aside from the obvious) is that they have  
the potential to be lifted and re-used when it comes time to deconstruct  
the building whereas a stabilised earthen mix is soil that has been imbued  
with so much stuff that it would be useless for trying to grow anything  
in. That ability to be re-used would help to amortise their higher  
embodied-energy over a longer period of time, thereby minimising their  
environmental impact.

And speaking of Wild Bill-Bob Christensen ...

How about thinking about breaking up the GSBN digest into chunks not  
exceeding 30 kb in length ?  ie On those rare occasions when there is  
unusually heavy traffic (like  Vol. #10, issue #3) 2 pieces of mail might  
be easier to sort through rather than one 64 kb-long mutha.


-- 
=== * ===
Rob Tom
Kanata, Ontario, Canada
< A r c h i L o g i c  at  Y a h o o  dot  c a >
(manually winnow the chaff from my edress if you hit "reply")