[Cob] Foundation @ Stone Haven

[Janet Standeford]

I will be giving a series of mini projects this way and when the web 
site is up and running, they will also be posted there. The website will 
have photos which will help with visualization for those who cannot make 
the trip personally.

Foundation: (Please give your opinion)

It is believed that the house will be built on the rocky outcropping 
where there is a natural terrace under a beautiful old Ponderosa Pine.

As the rocks are close to the surface there is an issue regarding tying 
the foundation together and not having to have a stemwall.

While it is preferable to not use any concrete and to only use natural 
materials, it is important to not let the foundation "sink" in a way 
that would unbalance the cob walls.

My idea is rather than using a rock cage in a trench, as the trench 
would be hindered by the boulders, what if:

Trenches were dug where possible "at an angle with the lower side on the 
downhill slope" and any size or shape of large rocks were rolled in and 
fitted in where possible, for the two feet of foundation. Then two feet 
of concrete would be mixed on site and poured to encompass the smaller 
rocks as well as the boulders when possible, tying everything together 
and allowing water run off to a channel on the hill side. Then the flat 
rocks and gravel in a plinth style upper foundation would protect the 
cob from the water and concrete as well as level the wall base.

The channeled water would run to the ground water run off pond/cistern.

Janet