[Cob] How to extend an urbanite foundation and drainage trench?

[Brian Liloia]

Hi all:

I am hoping to add a very small addition to my cob home this year: an
extension to the doorway to create something of a mini mud room (or
airlock). It will mostly consist of extending the foundation (and drainage
as well, I presume) by about four or five feet.

However, I'm not sure how to best go about this. How would you extend a
drainage trench without disrupting what is already there? (My trench is 18"
deep, filled with gravel and 4" perf pipe at the bottom).

Any suggestions? What would be the best way to dig the extended trench
without mucking stuff up?

(Here's a photo of the entrance - the wall will be extended to kiss up
against the exterior post:
http://www.flickr.com/photos/smallape/3531827579/in/set-72157604714762643/)

- ziggy

-- 
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I live at http://dancingrabbit.org
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