[Cob] plastic jugs in walls?

[Deborah Denmark]

Hi all,
First let me say that I am still just an armchair cobber, translated as:
have not built anything with cob yet, only have read several of the major
books on building with cob.
However, given what I understand from my reading, I think the plastic jug
for filler is probably not such a good idea for reasons already posted
regarding reduced stability and because one of the main features of cob is
mass to absorb passive solar heat in winter. It seems to me that the void
that would be created by the jugs would not serve that function well.
As for filling the jugs with water, I think there would be a high risk of
leakage due to pressure when the cob shrinks around the jugs.

If the only reason for thinking about using the jugs is to reduce the amount
of cob needed, I think I would go with stones/rocks instead and I would want
to test this method on an outbuilding first rather than build my house like
that without knowing how it would hold up over time.

Deborah Denmark