Plumbing and Concrete
With the tires done, it was now time to put
anchor bolts in to hold the bond beam for the roof
onto the house. In order to mix concrete, we
needed some water. We decided to plumb one of
the cisterns and have some water delivered. Each
cistern has a 2" threaded outlet in the bottom,
which allows for easy plumbing. I put three
reducers in a row to get to 1" copper tubing, and
installed a ball valve to shut off the tank if need
be. I've sweat pipe before, and it is pretty easy--
it's a little harder outside in the wind!
Because we dug the cisterns down another foot,
(previous pages) our trench is pretty deep. We
rented a ditch witch to get them dug quickly.
We'll run two lengths of copper pipe in the
end...one to use and one "just in case."
With water on site, we were ready to mix concrete. We
hollowed out a hole in every other tire on the top course.
The hole is as wide as a shovel blade and goes all the way
down to the cardboard.
We also dug out a space under the bead of
the tire. This is different than the
Earthship books, but we thought it makes
sense. We were careful to not effect the
level of the tire, but this way the concrete
gets under the bead and can't be pulled out
of the tire.
Next we plopped some concrete in the hole
and stuck in the anchor bolt. I used a 2X3
as a scree board and also to get the right
height on the bolt-- about 1/2 taller than
whatever you bolt down.
Then we filled the rest of the tire, being
sure to pack in the space under the rim,
and leveled it very well.
FINALLY! A job that only took one day!
Of course, we WERE going to do this
last weekend but it snowed and rained
and it all blew sideways!
Back to the
A quick word about concrete... Environmentally, concrete and cement are questionable building
materials. This is primarily because there is an extreme amount of "embodied energy" in them.
That is the amount of energy, mostly from burned fossil fuels, required to make, use and deliver
them. Concrete has more embodied energy than many materials. Second, concrete is not recycled
or reused very often, so disposal is a problem also. It is absolutely possible to build this house
without concrete. Our engineer wouldn't hear of it. The trouble is that concrete is so easy, readily
available and reasonably priced. It is also really durable. Sometimes it is hard to choose the
environment over convenience. I must say that even if we put in a poured concrete floor (which we
will probably do) our house will use less concrete than a conventional house of the same size--no
foundation was required! If we had more time, we would look at adobe floors, more money and we'd
look at flagstone floors.