The best solution to the problem you raised regarding chemical
sensitivity to liquid sealants is probably the use of extruded
thermoset (e.g., EPDM or silicone) gaskets. PVC, urethane and
santoprene are also available in various profiles, foamed and
otherwise, but would are less desirable because they are not as
inert as the thermoset resins. EPDM gaskets are used on a
widespread basis in manufactured Housing in Europe (esp. Norway,
Sweden, etc,) and also in most european windows. In the US liquid
sealants are usually preferred for these applications, with
associated off-gassing of solvents and other additives for months
or even years. The chemicals off-gassed by some are proabably
more offensive than others, however and the specific sensitivity
seems to be a very individual thing.
Unfortunately, this solution may not be at all helpful in a
retrofit situation such as the one you currently face. The EPDM
gaskets are typically placed during construction (e.g., between
sill plate and floor, between wall sections, etc.) and do not lend
themselves to remedial application. I would suggest a painstaking
process of testing various inert foam materials (which can be
forced into gaps) for sensitivity to the client. You probably
will not be successful in completely plugging all of the holes but
you may be able to get most of them. Be sure to deal with leaks
around interior wall surface penetrations such as electrical
outlets, lights, piping and fans. A variety of products are
available for this purpose and should work in a remedial
application.
As to the most natural material which can be found for this
purpose_ because of the growing number of people with MCS
(multiple chemical sensitivity)_and I have become one_ many
plastic product applications are being replaced with natural
rubber materials. I am not aware of any extruded gaskets or
sealants currently available in a natural rubber material, but if
not, one might bring it to the attention of a manufacturer such
as Monsanto (a large manufacturer of foamed gaskets and
weatherstripping). Who knows_ they might very well decide to make
such a product. Hope this helps. This is probably a good subject
for EBN if they haven't already addressed it. Nadav?
_____________________________________
Loren E. Abraham, AIA, IDSA
President - DTI/ERG
912 St Charles Avenue, Charlottesville, VA 22901
Vc: 804 296 4197 Pg: 804 963 1511 Fax: 804 971 3729
© 1997 Daybreak Technologies Inc. / Environmental Research Group
You wrote:
----------
> From: Marc.J.Rosenbaum@valley.net (Marc J. Rosenbaum)
> To: greenbuilding@crest.org
> Subject: GBlist: Natural sealants
> Date: 21 Feb 97 08:10:42 EST
>
> I have a building to fix where the owner was fanatical about
everything being
> natural and non-toxic. The problem is, it is incredibly leaky.
What
> substances are natural sealants, replacing caulks? Need to
accommodate
> movement, etc.
>
> Marc
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