Cob: Using Bricks While Building With Cob

[lightearth at onebox.com]

In my experience, bricks are not typically tough enough for ground or underground applications, they tend to crack up and that's real bad for a cob foundation.

Is it possible to get urbanite (local broken concrete) from a construction site. This we have mortared together with just a small amount of mortar/concrete and had good results. You can save the stones for the 'prettier' areas of the foundation. The broken concrete seems to be very strong as in the process of shattering it they (the demolishers) expose the fault lines of the weakest part of the concrete, leaving virtual stones that have hung together even during the equivalent of a massive earthquake (in terms of the smashing force against them). Urbanite can vary depending on how it was made/cured etc. but some common sense and visual and hammer inspection can give you an idea.

With all that said I favor making a rubble trench/drain foundation underground with this urbanite/rock/mortar on the surface of the rubble trench. One secret is to insulate the outside of the rubble trench to prevent water infiltration into it.

Another very real possibility that I've seen done but never tried myself is earth/sand bags  that are plaster over...there's some good descriptions at some websites (dont' remember which ones though)


I admire your spunk, we (Outta The Box) like to work with/for people with such open-minded thinking. BTW what area are you in, did I miss it ? Sometimes foundation requirements are quite specific to climate.

Best

Marlin

-- 
     Marlin Nissen
   - Outta The Box-
  lightearth at onebox.com
(608) 213-9405  Cell/voicemail




-----Original Message-----
From:     "Kim West" <kwest at arkansas.net>
Sent:     Wed, 4 Dec 2002 23:58:32 -0600
To:       "Cob List" <coblist at deatech.com>
Subject:  Cob: Using Bricks While Building With Cob

When I made my decision to build a cob cottage I used hundreds of pieces of paper, and probably five or six leads for my mechanical pencil, drawing plans and making computations before I ended up with what I now intend to build. At first I just drew what I wanted, but when I made a scale drawing it became clear that what I wanted and what would work were two different things! I then made more drawings and ended up with plans for a home that I thought would be, not only sufficient for my two children and me, but also very well planned as far as heating, cooling, ventilation, and passive solar heating were concerned. After weeks of excavation on the old house place here on our property  it soon became apparent that we were not going to find enough rocks to use in the foundation of the home I wanted to build. We did find quite a few rocks, some very large, and also a nice amount of bricks. I had intended to use the bricks on the floor and the rocks on the foundation, but once I realized there were not going to be enough rocks for the foundation I went back to the drawing board and "came down a thousand" as they say! I drew plans for a much smaller house that would just get us by instead of one that would be very comfortable; and instead of building horizontally, I decided to go vertical. It looks though as if we are still going to be short on rocks for a foundation that, without question, will be sufficient for our new home. I called the concrete places and found that it could be up to $800 to make up for our lack of rocks! It is embarrassing to admit, but a lack of funds is the major factor that played into my resolve to build with cob. I am a widow and have three children, two of which are still at home. I am trying to build a suitable home to replace the one we have which has nearly fallen apart. I figure if I go VERY small and economical with the new place, re-using everything that I possibly can from our present house and the old place, I might be able to afford to build a decent house so long as it comes out to $5 a square foot or less. Otherwise we will be stuck in this place, falling through rotten floors and freezing in the winter while burning up during the summer. Anyway, my reason for making this post is this: Has anyone here used bricks in their foundation to supplement the rocks? I figure that, if I find that it is safe to do so, I can use the bricks in my foundation and make other plans, such as clay slip, cob, or poor man's concrete for our floors. Anyone here have any suggestions? You can go to my geocities site and see pictures of the rocks and bricks that we have excavated if you would like. It takes a while for the pics to load though. I plan to keep the site updated in our progress towards a good home for us, and maybe soon I will upload some of the smaller drawings, plans, and computations I have made so that visitors will have a better idea of what is happening. Any help will be greatly appreciated and there is a guest book there if you would rather comment at my site instead of here. http://www.geocities.com/kwest_1961

Thanks,

Kim