About 40% of the world’s population lives in adobe homes. The thermal mass properties
are really good. Warm in the winter and cool in the summer.
Environmentally friendly, an earthen product, that has been around for more than
10,000 years.
You can make your own adobe bricks with a mixture of 30% clay and 70% sand. If not
sure about the mixture, put some in a glass jar, shake vigorously for 2 minutes, let
settle overnight, the sand will settle at the bottom, clay in the middle, and water
on top.
Typical mix is 5 gallons of water, 28 shovelfuls of adobe mixture and 2 shovelfuls
of cement. It is a stablizer and adds durability to the bricks. If you do not have
one, rent a cement mixer. A 2.5 cubic foot mixer holds 70 liters or around 19
gallons.
You can make your own molds or buy them. There are 3 basic types of molds. Standard
is a solid square. O-brick is a hole in the middle and a U-brick for a u-shaped curve
on one end. This allows for structural support like steel rebar and services
(electrical, plumbing). Weed mat or weed fabric works best to lay your molds on, not
plastic as it creates too smooth of brick. Make sure you are on level ground. Wet
down the molds before pouring in the mix to keep the adobe from sticking to the molds.
Use a shovel or concrete rake to spread the mixture over and into the molds. Work
the mix into each mold with your hands to get rid of air bubbles and remove any clay
clumps larger than 1/2 inch.
It takes 28 days for the bricks to cure properly. So take a break, or a vacation. A
properly cured brick is lighter in color and weight and when tapped, has a hollow
sound.
When ready to lay, make up another batch of mix just like you did to make the bricks.
Add 2 tablespoons of dishwashing liquid to this mortar batch and let mix for 2 minutes
to help it aerate. It is better to already have a level concrete footer solidified
with vertical re-bar about 3 feet high and 3 feet apart unless your wall is not going
that high.
With your hands, rubber gloves work great, lay 2 strips of the mortar 2 inches high
on the footer and lay your brick, wiggle into place. Butter the side of the next
brick and touches the first and wiggle into place.
Build your corners first, staggering the levels up. Stagger by using half bricks. Use
a line level, laser level or board with a level on top to keep the corners level with
each other. Then fill in towards the center. Fill any unused O or U bricks with
motar. To give that smooth finish, hand rub the wall with water and a little of the
adobe mix.
Oh, by the way, Adobe means “Sticky Pig” … do not ask me why.
