Cob lime-stabilized cob

[Michael Saunby]

> Hi Michael,
> 
> as a follow-up, one short question: Shouldn't the the grit be of a size of up to 0.4mm, or do I misunderstand the word?
> 
> Uwe

No it is up to 4mm.  The plaster on the walls here is made up of very angular
grit of about 2-4mm.  

Brick dust, portland cement and various other things have been, and often
still are (most common now is white cement) to speed up the setting
of lime mortar (otherwise it can take a couple of weeks to set).  However
since plaster is normally applied in quite thin coats 1/2 inch or less it
will set quite quickly, and perhaps more important is to keep it moist
to slow down the set.

> 
> (snip)
> 
> The Devon Earth Building Association give this mix for Roughcast Render:
> 2 x coarse sand
> 1 x grit (up to 4mm dia)
> 1 x lime putty
> Then 1 x bucket mix to 1/2 bucket of teased hair.
> 
> 

-- 
Michael Saunby