• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources the cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • r ranson
  • Anne Miller
  • Pearl Sutton
  • James Freyr
  • Mike Haasl
  • paul wheaton
  • Dave Burton
stewards:
  • Joylynn Hardesty
  • Jocelyn Campbell
  • Joseph Lofthouse
garden masters:
gardeners:
  • Carla Burke
  • Steve Thorn
  • Eric Hanson

Do interior cob walls need a rubble trench foundation??

 
Posts: 8
2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I can’t seem to get a straight answer on this... do interior walls in a cob house need a rubble trench or any other type of foundation under them?? Or a stem wall??
 
pollinator
Posts: 317
Location: Victor, Montana; Zone 5b
84
hugelkultur forest garden food preservation
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello, generally you don't need a rubble trench foundation for interior walls as the exterior wall's foundation will move any moisture away from the building. When I built my cob house I did 3' deep exterior and all the interior walls had shallow 6" rubble trenches just to help support the mass and define the areas, but they did not actually have any pipe or tiles placed within to move water out.

I do recommend building some type of stem wall. Again, this can be much lower than your exterior as you wont' have to deal with water splashing back from dripping rooflines.  You don't want cob directly on the ground as it can draw up moisture if you are not putting a waterproof membrane beneath it. Better be safe and build up at least 6"-12" off the ground before doing any cob work for interior walls. More like 18"-24" for the exterior walls. Hope this helps.
 
Hanna Sanders
Posts: 8
2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
That is exactly the information I was looking for. Thanks so much for the help!
 
no wonder he is so sad, he hasn't seen this tiny ad:
permaculture bootcamp - learn permaculture through a little hard work
https://permies.com/wiki/bootcamp
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!