[Cob] Foundations for stoves and interior cob walls

[Anna Young]

Yes, you are quite right, we aren't going to use less by thinning it, rather by tweaking the foundations so we don't have to use so much! Watching it all flake away over the next 20 years is not my idea of peace of mind.... We are using #5 rebar, and reading lots of foundation books to get it right (ish) with overlaps etc.

Anna



  Hi Anna
   Suggest that you do not thin out the concrete by adding water.  Best to keep concrete strength and use less.  (perhaps I missed your point here).  Rebar needs to have 3" of cover on all sides: so therefore: a 6" deep footing is minimum.  #4 bar (1/2" diameter) is most commonly used and placed so that bars are about 6" apart and 3" for edges.  Also the bar wants to lap about 15" to maintain strength at rebar joints.