[Strawbale] Moisture sensor redux (was Re: cement stucco problems?)

[Rob Tom]

On Thu, 19 Oct 2006 20:15:39 -0400, Mark Bigland-Pritchard  
<mark at lowenergydesign.com> wrote:


>> If the source of that moisture was excessively high ambient humidity   
>> levels (ie in excess of the danger point for straw) then I would  
>> question  their choice of a moisture-susceptible cellulosic material  
>> for their wall  insulation.
>>
> Well, there is now over 10 years of experience of sb building in  
> Britain, Ireland, the Netherlands and Denmark, over 20 in Brittany

>  Buildings in places as damp as Cardiff - and damper - have been staying  
> up.  Though there hasn't been much monitoring data,

I'm not familiar with the climates of "Britain, Ireland, Netherlands,  
Denmark, Brittany" (other than the air in parts of Britain being described  
as pea soup-like) so I can't comment on what might be happening there but  
I will say that a building "staying up" after 10 or 20 years really isn't  
any indication of whether or not there are moisture problems in the SB  
walls.

  (ie. I have hurriedly-built storage sheds on my property in which I  
consciously violated many of the rules of thumb of good building practise  
and they too are still standing and functioning after almost 20 years but  
I certainly wouldn't use them as examples of acceptable building practise.)

And the fact that there has not been much moisture-monitoring data would  
not seem to offer much in the way of fact for this discussion.

And I will also say that I know that an architect from one of the Euro  
countries quite recently reported serious moisture problems in the SB  
walls of an ~10 year old building that I think he said he designed and had  
a hand in building (this was on the GSBN List within the past 6 months ).

And if I recall correctly, he was thinking about installing a timber  
cladding over the plaster as a possible fix. What I do remember distinctly  
is that I was more than a little sceptical about the prognosis of success  
for the fix.

Perhaps one of the GSBN members who knows the case better than I, will  
fill in the details.

And I can also tell you that of the older buildings that have been  
reported (on the GSBN List) as having suffered moisture problems and for  
which advice was being sought for fixes, I don't recall there having been  
any solutions proposed (by the List membership comprised of the most  
experienced SB builders and thinkers on this planet), that were  
inexpensive or easy.

> And fortunately all the designers that people listen to in Europe have  
> thought about what they are doing.

Ehhh. I don't know about that either.

I do know that at least one of those designers/builders (in Britain and  
who is stridently pro-lime BTW) was advocating inset windows with no sills  
other than the plaster on the walls rounded over to form a sill of sorts,  
a detail that I wouldn't want to try even over here with more impervious  
Portland cement plasters.

===* ===
Rob Tom
Kanata, Ontario, Canada
<archilogic at chaffyahoo dot ca>
winnow the chaff from my edress in your reply