Cob render for restoration

[Mike Holland]

Hi, all.  I've had a look through the archives and can't find exactly what
I'm looking for, so I'll post this & ask your forbearance in advance...

We've recently bought a house in central France, about 50 miles from Paris.
It's an old farm, with four buildings: the farmhouse itself, a cow shed, a
pig sty and a large barn.  All except the pig sty are built with cob (or
'bauge' in French).  All the structures are single storey, with oak beams
etc.  Framing of doors and windows is in local brick, and the roofs are in
mechanical tiles, fibrocement  slates and corrugated iron.  Floors are
beaten earth in the barns and stables, hexagonal ceramic tiles in the
farmhouse.  The central portion of the farmhouse probably dates from the
18th century, possibly earlier. (If anyone's interested in the details, I'll
put some photos up on my website).

The problem is, it was owned by an old lady who had not done any serious
maintenance for years (I was talking to a neighbour earlier today, and he
told me that the roof of the house was last fitted during the war).  As a
result, the render on the facade is more or less falling away (along with
many, many other 'challenges').  Now, the walls are some two foot thick, so
they're not going to wash away any day soon (I hope...), but we want really
to replace the facade this summer.  Builders I've spoken to are keen to
smother the wall in concrete, but I feel that this would suffocate the
structure, and not let it dry naturally, hence hastening its demise.

What is the best mix for a render for this type of material?  Do you need to
put an armature (chicken wire?) on the wall to give the render some support
during application?  And what would you use for a plaster for internal
walls?  And in the large barn, one of the walls has started falling
outwards - does anyone have any experience of putting in iron tiebars
between walls??

I'd be grateful for any help: and any help with the myriad of other things
that need doing (no bathroom, no toilet, no wiring, no plumbing: we're
living in a caravan in the barn - not funny during the winter we've just had
8-))

TIA

Mike