[Strawbale] airtight plaster
archilogic at yahoo.ca
Sat Jun 9 18:26:24 CEST 2012
On Sat, 09 Jun 2012 09:56:48 -0400, Dave Howorth <dave at howorth.org.uk>
> I'd welcome any advice or pointers to materials about making
> straw bale walls airtight.
> I'm planning to use the indoor plaster as the main airtight barrier. It
> will probably be clay plaster, though lime is a possible alternative. I
> know a bit about tapes to use at window and ceiling junctions and so
> forth. My main concern at the moment is about how to use clay plaster to
> make an airtight barrier that stays airtight. So things like minimising
> cracking and so on.
This will be brief because I'm just on my way out the door.
I'd say that achieving air-tightness of the plaster is not so much about
minimising cracking as it is controlling where the cracking occurs and
then implementing a strategy to ensure air-tightness at those controlled
That means breaking up the plaster into panels of a reasonable size so
that shrinkage cracking within the field of the panel will be eliminated
(assuming that the proper mix proportions will be used for the plaster and
that proper curing of the plaster will be carried out etc.)
Anywhere where there is a control joint, including a flange behind the
joint in the plaster (or dissimilar planes/ materials) to ensure
continuity of the air barrier between the two (300 mm wide strip of
builder's poly or Tyvek or sheet metal or rubbery sheet membrane etc) and
detailing the interface as a self-locking mechanical joint rather than
relying upon goop is an effective technique.
=== * ===
Rob Tom AOD257
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")
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