Attaching
metal
lath
over concrete and foam insulation.
This seems lke a good method, although I haven't tried it,
it was submitted by a reader, Michael Krall . Thanks Micheal.
It seems an excellent alternative to furring concrete or masonry first,
before attaching
the metal lath. These fasteners were made for EIFS, but are strong
enough to work.
Care should be used to avoid embedding the lath into the foam,
preventing a key. Spacing should be an industry standard 12" oc,
horizontally and vertically.
Micheal writes:
Non-conducting masonry anchors for foam board application:
walrusbrand
This is the brand of fastener we are using. I talked with the
tech.
guy at Walrus
and felt he was pretty knowledgeable.
There is data on foam over masonry in a couple of the articles
here.
Paul Fisette is a really sharp fellow. Used to moderate the building
science
forum at Journal of Light Construction.
Years ago, in the planning and how to do it stage, I had conversations
with Paul about foam over Masonry.
What we are doing is attaching both foam and stucco wire (self
furring,
no paper backer) with the plastic anchors. I figured out that attaching
the foam with the fasteners and then wiring the stucco wire to the
fasteners
was going to cause the wire to be too loose and too far away from the
surface
of the foam. The attachment schedule is 24" horizontal and 18" vertical
with use of adhesive. That would switch to 12" vertical without
adhesive.
As an aside, there are a lot of adobe and rammed earth homes
built in
the southwest. Many of them have exterior insulation board with stucco
over. Most of these buildings have the foam nailed on with double dip
hot
galvenized nails (thin shank types are better).
I originally came across the concept of exterior insulation in
the old
passive solar books then cross referenced it to adobe/rammed earth (we
built a passive solar adobe shop before we started the house).
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