Cob: RE:Jill's questions

[Amanda Peck]

1) Not unless they are a) load bearing (maybe not even then QUITE as thick) 
or b) you want them that way for aesthetic reasons, because you want to 
embed closets and cubbyholes in them, or because you need the sound 
deadening.  Remember that they will need to be supported from underneath.  
It’s not like putting a stick-framed non-load bearing wall on a wood floor.

2) There’s at least one architect who subscribes to this list, but he hasn’t 
been picking up his emails lately.  There are more who can do it.  Local to 
your building might be a good idea.  Also, consider that a DRAFTSMAN might 
be able to draw up your plans a good deal more cheaply.

The more work you do with your plans the better off you are.  Put as much 
detail as possible into your visualization, with  surfaces, colors, textures 
  Mentally walk through your house.  Bring in armloads of groceries and see 
why a shelf outside the door to put them while you fumble for the keys is a 
great idea.  Put them away.  Cook a meal, and then clean up.  Have your 
mother come for a visit.  Allow the minister of a church you don’t and won’t 
ever belong to to use your toilet.  Where do you want electrical outlets and 
switches?  Does your utility room have to be outside to accommodate a 
battery bank as well as charge controllers and inverters?  Or can it be 
inside with just a washer and a fuse box? What is your route from washer to 
clothesline (or do you HAVE to use a dryer all the time)?

The more work you do the less likely you are to have a second floor with no 
stairs up to it (it’s happened!) or have the kitchen cabinets just strong 
enough for particle board and Formica when you said at least 20 times that 
you wanted granite.

Remember that plumbing and wiring have to be planned in from the beginning.  
The latter is the one thing that will almost certainly have to be inspected. 
  Find an electrician, talk to your local utility EARLY.  It’s not like 
wiring a stick house, where you can change your mind up to the point that 
the drywall is put in.  Cheatham County Tennessee, for a straw-bale 
building, wanted armored cable or conduit.  Probably not a bad idea for cob. 
  And for plumbing, you want to do advance planning so that leaks can’t take 
out your lovely cob walls, or require unbelievable amounts of expertise, 
energy, and money (comparable to replacing a foundation and basement wall) 
to fix.

3) Cob will take care of at least some of the moisture management.  You will 
probably want windows that open in the spring and fall--if not summer, air 
intake for the fireplace or wood stove, maybe something on the order of an 
air-to-air heat exchanger.  But those goodies are expensive, and require 
(full-time?) electricity.  I suspect that one can improvise them, but I’ve 
never seen one.  Solar attic ventilation works when you need it--when the 
sun is shining.  And you do want air movement under your roofing even if you 
don’t have an attic.

4) Foundation.  Traditionally twice the width of the (bottom of the?) wall, 
depending on soil conditions.  Straw bale people can get by with less.  Cob 
can’t.  This is what goes below the frost line.  There are ways around it, 
but plenty of alternative building people are using them.  You do have to 
provide for drainage around the ground below the building, and support for 
the building somehow.

Footing.  It goes from the foundation to wherever.  Plates, girders, floor 
joists in a stick built house, or something similar if you plan on a wood 
first floor.  18 inches above ground if you live in termite territory.  Ask 
someone else about ventilation vs. insulation.

Stem wall.  This may be the above ground continuation of the footing (in or 
not in the same materials) if you aren’t using a wood floor.  The purpose is 
to keep rain and floods (inside and out!) away from your lovely cob wall.  
Two straw bale building’s I’ve helped with had 6-8 inches inside on top of a 
concrete floor.  Since then concrete has gotten a bad reputation.  Outside, 
depending on the contour of the land, how much roof overhang you have, and 
how you want it to look and work, anything from one foot to six.

Jill wanted to know:
1. Are interior wall just as wide as exterior walls?
2. Does anyone know an architect that can take our floor plan drawing and 
create plans? We want to be sure to avoid costly mistakes, and we have no 
experience building a house.
3. What about air exchange to prevent moisture build up? (My family built a 
house - stick house - and forgot about this, and now the upstairs walls are 
peeling)
4. You make the foundation higher than the frost line by how much?








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