Cob: stucco question

[jamie.ayres at m2.com]

>Although a waterproof layer is supposed to cause trouble with 
>delaminating  and sloughing, it sounds like the only solution in some 
>locales.  Like wind-driven rain locales where three foot eaves aren't 
enough.
Yeah... it's not necessarily the only option but it's probably the most 
affordable and durable.

>Jay, do you see patching or constant maintenance where people in England 
>use that tar  paint on cob?
MAny of these places are now owned by people who don't know the 
significance of the paint and probably do it because the houses have 
always had it... but I guess you're probably looking at a recoat of the 
stuff every few years to ensure that it stays waterproof.  Considering the 
amount of work needed to replaster the bottom couple of feet of the house 
every few years it's a small price to pay!

>I've seen pictures of the erosion that backsplash causes, and I wouldn't 
>want it on my house.  That's why I like the three foot plinth that Mike 
Wye 
>recommends.
This is the deep stone base to the walls?  A very nice idea. In England 
cob houses were originally made from cob from the ground up.  They were 
only meant as temporary dwellings anyway, to last a generation or so.  As 
the wood (which was often used in cob buildings to form the roof and was 
inlaid into the monolithic walls from the base of the wall for strength) 
rotted when in contact with the ground they started putting the wooden 
posts on stone slabs.  Over time they realised that they could help 
prevent a lot of the rot and degradation at the base of walls by adding a 
few courses of stone. Stone was waterproof as well and so this prevents 
rising damp from ground level and also stopped the base of the wall from 
getting so badly eroded by the weather.

However, stone was costly and cob wasn't so stone was rarely used for more 
than the first couple of feet at the base of the houses.

Stone is still is expensive (unlike tar paint)! But using it is an 
attractive alternative to concrete and will last as long if not longer. 
Plus it forms the base of the house rather than a coating on the side of 
it.  I'm guessing that you'd have to be careful with the lime mortar that 
you used to hold this stonework together in order to ensure the wall is 
strong enough to bear the weight of the house on top of it?

Good luck!

Jay