permaculture

["John Schinnerer" <john@eco-living.net>]

Aloha,

Thanks for the details.

> On the lama tank we used that tied
> in a circle with another piece cut for a bottom, plus a third piece cut
> for the top to form a cone. Added 3 loops of galvanized wire, maybe #9
> or so, around the sides of the tank and that was it. No rebar. tied on
> one layer of expanded metal lath. no chicken wire. Cheap as could be.

Yeah, probably fine for circular water tanks where the stresses are real
simple and even.  Remesh and wire loops give the big-picture tensile
strength and lath gives the small-picture (6" square area, many many of
them :-) tensile strength. Did you use the light or heavy weight lath?

My friend's goat shed is just lath (over rebar and heavy wire to give it
shape) and it's pretty solid - I've walked around on the roof - I think he
used two layers of lath but I'd have to check to be sure.

I wouldn't want to build something like mine with just one layer of lath
everywhere unless I didn't mind it being a total experiment...the stresses
and loads are much more complex...doors hanging off it, roof stringers and
trusses sitting on it, not a pure circle shape, etc..

The very top edge as it rises towards the front on my structure is one
layer of lath only (above the 6 ft. height of the mesh layers).  I cracked
a corner loose putting a truss end in place in a cutout (crack barely
visible coming out from behind the metal bracket in third pic on page 5),
just by bumping it outwards a bit too firmly as I was trying to position
the truss.  The lath kept it from breaking off, but I could wiggle it
enough to consider it no longer structurally sound.  Luckily it wasn't a
load-bearing spot that I damaged.


John Schinnerer, MA
-------------------------
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Cultural & Ecological Designing
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