[Cob] RE: Roofing material?

[Barbara Roemer]

In our area (Northern California), we can buy discarded sheet metal used as
printing plates at the local newspaper.  Coverage is almost 2 sq ft for $1-2
bucks.  I, too, would like to mess around with clay tiles.  An adobero in
the Modesto area makes stabilized paving block in various thicknesses from
2" to about 4" with, I think, 10% concrete, which has stood up beautifully
outside in driving rain, 60" per year, with no sealer, no protection, and
looks equally handsome inside in high traffic areas.  Thickness is required
with that little stabilization, which would be too heavy.  Second thought is
to make clay roof tiles and fire them in a reduction pit, raku-style.
Shaping them over the thigh is the way it's been done historically.

Don't know that I would find water draining from a living roof potable
anytime soon.  Ours is compost tea and we recycle it to the veggie beds.
Organic matter, provided to the plants there in the form of straw, does what
it's supposed to do - decomposes!  Runoff is still very rich the second
winter.

Barbara