About Hybrid Adobe
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How To Make Hybrid Adobe
This Page Contains a Quick Summary of Hybrid Adobe Recipes and Small-Batch
Disclaimer: This building method is relatively new
and may still be considered to be in the experimental stage as builders
are coming up with the best recipes for their needs, and adding new ingredients.
Even though these buildings are remarkable, remember building with Hybrid
Adobe, papercrete or fidobe is done at your own risk. Improperly built
structures, as with any material or procedure, may collapse causing injury
or death. You are responsible for the safety of yourself and those who
use your building. It is up to you to build properly and safely. Adhere
to local building codes where applicable.
Glossary of Terms:
Hybrid Adobe (aka hybradobe, hybridobe, and hyperadobe) is a mixture
of papercrete and fibered adobe (aka fidobe). It may also include medicinal
herbs, other fibers, and glass
Papercrete is made of paper, water and cement (or clay/lime
mix, AKA Roman cement)
Fidobe (Fibered Adobe) is made of paper, water and earth
To try to avoid general confusion the term "Hybrid Adobe" will be used
unless the application is specific to papercrete or fidobe.
Hybrid Adobe Recipes:
There is no exact recipe, allowing one to be less careful than in making
concrete. If you add or forget a shovel full of clay or cement, use too
much water or not enough paper, your Hybrid Adobe will still be usable,
however the properties will change.
Main ingredients by Volume
Here are four typical mixes.
Recipes are given in percentages, by volume. These can easily be converted
into shovel-fulls or pail-fulls, for instance by calling each unit
10%. Note that Roman cement can be substituted for Portland cement if
you want a more natural mix. The earth you use should have a high clay
content. What is referred to as "wet
paper pulp" has been drained on a screen and still contains a lot
of water. Add water if necessary during the mixing to adjust the consistency
depending on your application. Recipe number 1 will result in
the most hard and dense material, and the following recipes
result in lighter and softer finished material as you go down the list.
- 50% wet paper pulp/ 30% damp earth/ 10% dry sand/ 10% Portland cement/
- 60% wet paper pulp/ 20% damp earth/ 15% dry sand/ 15% Portland cement/
- 65% wet paper pulp/ 25% damp earth/ 10% Portland cement/
- 70% wet paper pulp/ 15% damp earth/ 15% Portland cement/
Note: Earth can be sandy dirt, clay, clay/sand mix, etc. (you don't
need to purchase washed sand. Usually digging a hole in your yard will
work, but conserve your precious topsoil. Some clay is beneficial. It's
a good idea to screen the dirt to get rocks and debris out, especially
if you are mixing a finish coat)
Main ingredients by 200-gallon mixer load:
- 1-2 large bags of Portland Cement OR use a clay/lime mix (approximately
- 5-25 shovel fulls of Earth
- 70-80 lbs. of paper (4-5 bundles of newspaper, approximately 12" thick)
- Approximately 160-190 gallons of gray water, city water etc.
Additional optional ingredients to be added to the mix:
- Small amounts of aggregate (small pebbles etc.) to increase thermal
- Herbs (sage, eucalyptus leaves, tea tree leaves, lavender etc.)
As an optional fibrous addition to the paper pulp, one can use:
- Sawdust (sawdust has proven to be a less-than-ideal fiber. Experiment
before planning your project with this.)
- Dried weeds or grass clippings
- Straw (traditional adobe uses mixed-in straw for strength, often
- Hemp fiber (an amazing fiber imported from Canada)
Additional items to be added to walls during construction:
- Glass bottles to let light through the walls.
- Miscellaneous items to embed in the walls, get creative!
- Plastic is currently not recommended due to potential outgassing
of petrochemicals over time.
Suitable Paper Products for Paper Pulp:
- Newspaper (best source)
- Magazines (magazines are excellent because the magazine paper has
a small amount of clay in it)
- Junk Mail (better to first remove plastic envelope windows)
- Phone books
- Office paper
- Corrugated cardboard from boxes
- Packaging boxes (egg containers, cereal boxes, etc.)
Important things to remember:
- Use at least one bag of cement per 200-gallon mixer load, any less
and the material can be slowly pulled apart. A full bag is recommended.
- The more cement you use, the harder the final product will be, but
there is a limit. Two bags should be plenty.
- The less earth you use, the lighter in weight the final product will
be, and the quicker it will dry. If you use no earth it will shrink
and potentially show small cracks. Some sand or clay is recommended.
- Experimentation is fun. Try different ratios and ingredients, and
applications. There is no one way to make Hybrid Adobe, papercrete,
- Soaking the paper overnight will help break the paper down into a
pulp and will save wear and tear on the mixer motor. This is highly
- Try to keep small rocks and other extraneous materials out of the
mix before it is pulped and blended. They will only wear down your
blades faster and make the motor work overtime. They can be added later
- Don't over fill your mixer with paper or water, as then you must
drain some ingredients out, and that adds a lot of work.
- Collect paper
- Create a mixer or build one with friends and share the costs
- Obtain Portland or Roman cement as your bonding agent
- Create or find forms (small cardboard boxes, old drawers, used
dimensional lumber screwed together)
- Set up your work area (get screens placed over corrugated metal,
tarp what you don?t want to be splattered, set up a way to reuse gray
water if desired
- Soak the paper overnight
- Load the mixer with water and paper about half full
- Blend into a pulp (the consistency of cottage cheese where you can
no longer read any of the newsprint)
- Add cement, earth or clay/lime mix and blend it in
- Pour the load into a draining area or directly into forms (if you
use cement it is best to use the material before 12 or 18 hours passes
because the cement will begin to set-up in a chemical reaction)
- Pour into forms and let dry
- Cut the material smaller (if desired) within 2-4 hours after pouring,
but not much sooner
- Remove the forms after a few hours or overnight
- Place the blocks off the ground on pallets or some way to also
dry the bottom. These blocks can also be baked.
- When they are hard and lightweight you can use them with the same
wet material for mortar (use enough cement)
- Build your walls and finish the walls with a sheathing coat to
strengthen them further
Applications for Hybrid Adobe, papercrete and fibered adobe:
- Bricks, blocks, and logs
- Tilt-up walls
- Sprayed walls
- Interior insulation panels
- Exterior "out-sulation" panels
- Scratch coat
- Final surface
- Poured floors (use harder mix with more clay and cement)
- Roofs (recommended to be sealed, covered or in some way protected)
- Sculptures and furniture
in-depth information on how to make and use Hybrid Adobe, you may want
to purchase The
Hybrid Adobe Handbook.
Philip Mirkin showing paper pulping technique using off-the-shelf power drill,
custom pulping bit, and 5-gallon bucket. Photo by Hazlitt Krog.