Cob Temporary roof: ideas needed.

[Mike Carter and Carol Cannon]

Hello, Natural Builders.
This is being sent to 2 lists so apologies for any duplicates.

We're looking for some advice about an inexpensive roofing material to use
in a temporary application.  The structure is a storage shed (not
insulated); walls of cob, with a conical roof.  Rafters are "cedar" poles
12' long with Yaupon battens (latts, purlins, whatever they're called).  The
battens are irregular in height, with 2" to 3" above or below level possible
between rafters.  Eventually the structure will be thatched; for a year or
so the temporary roof will have to do.  We can consider any material that
has a high recycled content and/or can easily be reused or recycled when it
is time to thatch the roof.  The roof will be subject to strong downpours
(15" fell in a day 4 weeks ago) and unrelenting "subtropical" sun.

The roof area is 300 sq. ft. with 2' eaves.  Tarps (heavy trucking type)
have been suggested but the conical shape and joints are an issue.  Is there
anything that is somewhat flexible and shingle-like and does not require
underlayment?

Thanks,
Mike Carter & Carol Cannon
cobcrew at sprynet.com
http://home.sprynet.com/sprynet/cobcrew
Austin, TX    USA