These pages are just a brief
introduction to earthbag construction. If
you're new to it, we offer an overlook to the
fundamentals. There are plenty of books & websites
out there that go deeper into the subject than we do.
The best way to learn, though - as with so many other
things in life - is by doing. Getting your
hands dirty, so to speak.
Start with the basics. Take some clay-rich dirt in your
hand. Moisten it, squeeze it, roll it into a snake. Now
add a little sand, squish it into a form, lay it in the
sun & let it bake for a few days. It gets hard.
Congratulations... you've just made adobe.
If you put this wet clay/sand mix in a sandbag &
stack the bags, pound them flat, smoosh them around to
your liking (straight lines, curves, rounded corners,
whatever) and let them dry, then you have earthbags -
modular building blocks, adobe bricks in a bag.
Alternatively, filling your bags with dry scoria
(lava rock) avoids the need for mixing soils or adding
water. The voids in the scoria provide significant
insulation (R-value), the bags are lighter in weight
(easier to work with), you can buy them from us
pre-filled if you choose, and you can build year-round
(unlike earthbags, which require warm daytime
temperatures for the mud to cure).
With the right fill & a little finesse, earthbags
are stronger & more stable than concrete blocks.
They're low-cost, low-tech, have a relatively low carbon
footprint, they're fireproof, and - depending on your
fill material - are free of the chemicals &
outgassing that are increasingly common with many modern
The idea of using dirtbags/earthbags isn't new; think of
the sandbag trenches &
fortifications from World War I. There are suggestions
that they were used as far back as the Revolutionary
War. The Industrial Revolution allowed mass production
of textiles; before that, baskets filled with dirt &
rocks (the predecessors to gabions) were used for
fortifications as far back as Mesopotamian times.
But the application of bags with a wet fill (mud)
that'll set up, as an alternative building material, is
fairly new. It dates back to around the 1960s and can be
largely credited to two individuals.
One was Edward
Dicker, who patented the "Stack-Sack" process in
the 1960s (burlap sacks filled with a dry mix of sand,
cement, and gravel; soaked in water & then stacked,
with rebar driven through every couple of feet to anchor
Further refining the concept was Iranian architect Nader
Khalili, humanitarian and founder of the Cal-Earth
Institute, who recognized that people left homeless in
war zones and disaster areas around the world often have
(if little else!) abundant access to three things;
sandbags, barbed wire, and dirt.
Earthbags are ideal for bordering sinuous walkways,
garden beds, terracing, erosion control, building
arches, serving as foundations or stem walls for cob or
straw-bale constructions, or more ambitious projects.
Once they're fully cured & well plastered, no one
would know that they're not adobe (or something more
- Aesthetic - easily covered with plaster or stucco
- Versatile, graceful, and easy to work with
- Non-toxic - no fumes or allergens
- Low-tech, requiring a minimum of tools or experience
- 12" thick walls provide superb insulation
- Stable; superior earthquake, tornado and hurricane
- Tamped dimensions of standard 14"x26" bags at a
manageable 30 lbs each = approx. 12" wide by 12" long by
3" high. If you choose, you can pack up to double the
amount of fill in the same size bag to achieve a 60 lb.
bag with tamped measurements of about 18" x 12" x 4".
(Bigger bags mean fewer bags, but they're much harder to
Making your own:
With the basic materials (bags, dirt, barbed wire to
lock rows of bags together, and a tamper), anyone can
design and build with earthbags. If your dirt doesn't
have sufficient clay, you can add it, or stabiize
it with lime or cement.
You don't even need to buy bags. Sure, we're happy to
sell them to you. But some people have had success using
alternatives like thrift-store pillowcases, sheets sewn
together, etc. The point is to have a container or wrap
that will hold & confine the wet fill, and that will
survive the tamping without splitting a seam. Once the
contents of the bag have cured & and your
construction is plastered, it doesn't matter at all
(structurally speaking) what the bag was made of.
If you're new to this, you'll find information, links,
and resources on these pages & elsewhere to help you
Empty bags (click
to see prices):
bags are14"x26" (approx. 36 cm x 66 cm) and can
hold up to about 50 lbs. of fill. These are
medium-weight (10x10 weave, 850 denier, superior to the
cheap bags sold online), have tie strings, and are UV
treated to provide about 6 months of protection.
Large polypropylene bags
are the same as the above, but measure 18"x30" and can hold
between 75 and 100 lbs. of fill. These can be difficult to
manage when using for building.
burlap bags (new, additive-free, 9 oz.
weave, 14"x26") are a bit expensive for construction
but are excellent for gardening and matanzas. We
occasionally carry larger untreated burlap bags
(18"x30" and 23"x40") which, among other things, are
just the thing for sack races.
(dipped in a copper solution to help
prevent rot, mildew & to deter critters) run
about 12"W x 14"L and are $2.00 each. These meet
US military specs CID A-A-52141 and are made in
the US. Good for erosion control and that
underground bunker that you've been thinking
polypropylene bags (14.5"x26", rated for 4
years). More expensive than standard ones, they're
tarp-weight and will pretty much withstand anything that
nature & the elements can throw at them. Available
in any quantity, they're best suited for long-term
deployment for flood or erosion control.
(otherwise known as Superadobe) come on rolls in several
widths & lengths. We can get these in a variety
of widths & lengths. These are special-order and
require advance payment, but come with free
bags (assorted sizes) are typically used for
filtration, storm water control and ballast.
They last for years and can be emptied & refilled
multiple times. Nice to have behind your back seat if
you get stuck in mud or in snow.
We provide 4-point barbed wire in rolls or
by the foot. This is used between the courses of
bags to lock them together. We also provide tampers,
bag fillers, sifters, zip ties, trowels - pretty
much anything you need. See our store here.
If you live out in the boonies & want us to find
you something to add to your order (whether it's a
mantle for your Aladdin lamp or chocolate espresso
beans from Trader Joes), we'd be happy to look
around & give you a quote.
After building, you'll need to cover your structure.
Popular materials include lime, cob, adobe mud,
papercrete, stucco, and earthen plasters. Typically,
you'll want to add one or more rough basecoats, and then
a finish coat that will add color, texture, durability,
and weatherproofing. Check out our
pages (in progress!).
New Mexico residents, please add NM gross receipts tax
of 7.5% to all orders.
All sales are final. Defective merchandise will be
cheerfully replaced at our discretion.
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not to use
concrete (cinder) blocks