[GSBN] Gypsum

[forum at lamaisonenpaille.com]

Like Bill (and probably many others) I too used to think that the Earth 
was flat,.... uh..... that gypsum is only to be used on interior walls. 
That was until I saw a beautiful rose gypsum fountain on an ecological 
festival. The point the stand-holder wanted to make with that fountain 
was that  certain gypsums are remarkebly water resistant. They can and 
have been used on façades for centuries (in fact since 7000 BC). The guy 
wrote a leaflet on the production of natural gypsum but unfortunatly it 
is so thin I cannot locate it in my library so I cannot find the name of 
the guy who deserves the credit. He told me to not make the very common 
mistake to think that the gypsum we find in the regular building store 
is really that: pure natural gypsum.

As for Mark Potin of www.platre.com. I found him to be passionate and 
very knowledgable both in building history and in science (wich of 
course makes him the perfect gypsum salesperson). Quite a few positive 
things can be said about good natural gypsum but I'll leave that up to 
Mark. Like Kiba, I would very much suggest CASBA or any other SB 
organisation that holds gatherings to invite him for a presentation.
I can also invite him on the GSBN if you don't mind another garlic eater 
on board (lucky for you smell is still not transferred as an email 
attachment).

To cite a phrase Marc wrote to boast gypsum plaster when talking about 
the abundance of outside gypsum plaster in France, Germany, Middle & Far 
East and coastal North Africa (replaced by hydraulic binders since the 
early 20th century) : "...in Paris of course, but also in  Rouen and 
Biarritz, there are still tens of thousands multi story buildings (up to 
5 stories) of post and beam filled with cob or gypsum that are gypsum 
plasted on the outside".

Since my gypsum revelation at the ecological festival I've been 
searching for documentation on its traditional use but have yet to find 
a 300 page book on the subject.

Bye,
André 'old worlder' de Bouter
France




>>
>>
>> Now, when we are shifting this fascinating discussion about expansion 
>> joints towards use of lime, cement, clay and gypsum on straw, I'd 
>> like to contribute with draft of a report from a meeting with a 
>> knowledgeable person who is convinced the gypsum plaster is the way 
>> to go (I believe Andre, who has been previously trying to bring the 
>> gypsum plaster to our attention, knows Mark - he is quite famous in 
>> French strawbale building circles - and, as he is frequently selling 
>> his products in America, may be in the US as well?), Please see: 
>> www.amazonails.org.uk/gypsum.pdf
>>
>> Many thanks,
>>
>> Love
>>
>> Kuba
>>
>
>
> I think it's important to point out that gypsum is limited to use on 
> the interior walls of the building and by some reason combining it 
> with lime makes it supposedly suitable for exterior use, I would say 
> that it would be highly questionable.
>
> Bill
> Athena & Bill Steen
> The Canelo Project
> HC1 Box 324
> Canelo/Elgin, AZ 85611
> absteen at dakotacom.net
> www.caneloproject.com
>
>
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