The ‘Earthbag Shield’ covers and protects earthbag homes.

The ‘Earthbag Shield’ covers and protects earthbag homes.


What is the Earthbag Home Shield? It is a steel roof system intended to cover and protect an earthbag home.

The one aspect of earthbag construction that I struggled with the most was the roof. We here at Cozy Home Plans have come up with a great option to cover your EB home.

Benefits of an Earthbag Shield:
– It provides a completely covered and protected work area during the construction of your EB home.
– Aids in the necessary UV protection required during the construction phase.
– It gives you a completed primary roof allowing for many more cost effective options when choosing your ceiling options.
– The Shield creates an air void in between both structures to aid in heating and cooling the home.
– The roof trusses allow points for the anchoring and stabilizing of the walls to the roof.
– It gives your home a more traditional Ranch home look after the walls are finished.

The EB Shield is available in three different sizes… The 24′ x30′ is pictured above. Just add dirt, windows, doors, insulation, permission from your local building authority plus a few more things, mix together. Voila… you have a home that you probably paid cash for and did most of the work yourself.

24’ x 30’ $3,897.00 Includes 1000 new 18” x 30” Polypropylene Bags and Bonus Kit
24’ x 40’ $4,497.00 Includes 1300 new 18” x 30” Polypropylene Bags and Bonus Kit
24’ x 50’ $4,997.00 Includes 1500 new 18” x 30” Polypropylene Bags and Bonus Kit

Source: Cozy Home Plans
Earthbag buildings tips for solo builders

[This idea is popular with strawbale builders to protect the bales during and after construction. It’s especially practical in harsh climates, where it’s blazing hot or where there’s heavy snow or rain. Wide roof overhangs like this protect the plaster, doors and windows, and create wrap-around porches — a nice way to add extended living space at low cost (this is a topic of an upcoming blog post). Also note, you can use various roof styles to gain the same benefits.]


Comments

Earthbag Shield — 26 Comments

    • These are standard structures available all across the US and many parts of the world. Look in the yellow pages of the phone book for Farm Buildings, Steel Buildings, etc. You can order any size and shape. Engineering is included to meet code. Buy local to save shipping costs. Add your own earthbags, straw bales, etc. later after the inspectors are gone.

  1. Does the price include the shield as well, and all of the other things listed;
    24’ x 50’ for $4,997.00
    Includes 1,500 new 18”x30” Polypropylene Bags, 4 rolls of 4 pt Barb Wire, and 20 ea 1/2″ Rebar 20′L?

  2. Most certainly the joist could extend out to the beam line, but only if the beam line was engineered to carry the additional weight. I have had a bit of experience with steel structures. Some are more then stout enough to carry the additional weight and others are not. One would need to see the engineering. I didn’t think it was good to give the impression that joist could be attached without the additional information. Also R_W seemed to indicate that the joist would just be supported by the EBWs alone.

    Something that might need to be addressed by running the joist out to the beams is load transfer. Load transfer would occur if the non bearing walls were carrying any portion of the roof/ceiling weight. Some building departments make a big deal about this and others don’t. Usually this is solved by having the joist float above the wall.

    .

  3. I’ve done the “roof first” approach for a few buildings, but never with an earthbags. I am not sure how you can tamp the last few courses of eartbags with a roof in the way.

    It is definitely much nicer to work in the protection of the roof, especially in hot climates.

    There are lots of methods for reducing the cost, including Acrylic concrete, micro concrete roof tiles, ferrocement, etc.

    • Note now the roof overhangs the walls about 3-4 feet. You could go larger in hot climates or where it’s rainy. This means the roof is high enough above the earthbag walls so you can tamp the bags. You may have to modify your technique a bit depending on how much space you have. For instance, you could use a ‘tool’ made from a wooden 2×4 and hit the bags with a swinging motion while standing on a ladder. Carve a handle on the 2×4 for a comfortable grip.

  4. From Kevin: The Shield is actually a whole house kit that includes bags, rebar and multiple rolls of 4 pt barb wire. I now have better explained that on the website. That should help justify the price, especially if you have priced steel lately. Which in all honesty the kit has very little profit, I chose only the thicker gauge materials. These things will last many, many decades if properly maintained. It’s exciting to think about people getting all the basic components in one package, a home for just a few thousand bucks.

    • If the price includes the rebar, barbwire, bags and roof components it is a pretty good deal. I would recommend that Kevin add the package weight and a shipping cost table to the site. That way interested customers have a way to figure total cost.

  5. I have come across this on the net, the Portable Roundhouse, http://www.homeearth.tumblr.com, something along these lines would be ideal for temporary cover while building, just scale its size up to suit.
    Excellent site Owen, have learnt heaps of new stuff. Keep up the good work!

    Mike
    South Island
    New Zealand

  6. I am with Ronin. I believe the roof structure could be built for less. The concept of putting the roof on first is great, but not sure how cost effective a prefab metal structure is. As with anything the trade off in cost would be pre-cut materials, faster assembly and easier building dept approval. Most metal structures are pre-engineered and carry warranties.

    If the roof kit didn’t contain ceiling joists, the insulation choices for these roofs would be limited to foam. Either sprayed or in sheets. Both would require a finish layer. The roof design might not be engineered to carry the additional weight of finished material. Sprayed foam while excellent is expensive and generally not a DIY project.
    If the kit contains ceiling joists, cellulose, wool or even mineral wool/fiberglass could be used. Most DIY ‘s can install these.

    All metal uninsulated roofs are loud when it rains. Not bad in a sprinkle, but in a downpour/hail storm they can be deafening. Most modern houses mitigate this problem by laying the metal roof over a plywood sheeted base. The plywood deadens the sound. The Cozy site doesn’t indicate what all is included in the kit, but I would guess the roof is uninsulated steel on steel. much like most metal barns or garages.

    The Earthbag Shield would be a good option in climates where the need for insulation would be minimal and fast construction necessary. Of course there is also transportation costs which could add substantially to the project.

    • What I’m advocating is the concept, not a particular product. But you have brought up some good points about ceiling joists, noise, etc. Like every step of a project, you want to think through all options carefully.

    • I agree that you could find a better price if you shop around. But look at the total installed cost when you compare, including your time.

      When you do this, you still would put an insulated ceiling on the earthbag portion, but it can be a flat non-bearing ceiling–purely for insulation (both heat and sound). The large air space between the outer roof and inner envelope make for a shade and passive cooling benefit in hot climates.

      • “When you do this, you still would put an insulated ceiling on the earthbag portion, but it can be a flat non-bearing ceiling–purely for insulation (both heat and sound). The large air space between the outer roof and inner envelope make for a shade and passive cooling benefit in hot climates.”

        If a ceiling is being supported by the earthbags, then the earthbags are bearing. They are carrying the load of the ceiling and insulation. It is entirely possible that the ceiling with drywall and insulation would be heavier then the metal roof.

        Cost wise any prefab, precut materials are going to be more expensive then just the raw materials themselves.The value of the cost difference can be weighed in convenience, time or labor savings. A metal roof of this sort would be ideal for more temperate climates. In extremely hot climates some sort of venting would be necessary to keep the attic space cooler .In SoCal attics can reach 40-60 degrees over outside temps. Desert temps here can easily reach 110 degrees. A 170 degree attic would need some way to allow the heated air to escape. A minimum of either roof or gable end vents would be necessary. Ideally vents lower to allow cooler air to enter and high vents to provide exhaust would create a nice convection current. I wouldn’t recommend leaving the overhang to attic space area open. Usually areas like that are an open invitation to birds, bats and other assorted varmints. A pony wall to cut off access to the attic really should be considered. Of course one could sheet the top area of the joists, but then your doubling the work and materials. In hot areas most places recommend a minimum rating of r30. That is 8 to 12 inches depending on type of insulation.

        • The ceiling joists could run out to the beam that’s supported by the posts. So there would be almost no load on the walls. You could cover the porch ceiling to keep birds, etc. out.

          And for sure, design for your local climate.

  7. Hello Mr Geiger!

    Thank you so much for sharing so many great stuff! We´re are building a huge 9,8 m diameter dome here in Brazil, and we learned a lot from your videos and articles. We´re using 90cm walls, and our design has one floor underground. I Hope to share some of the adventure of filling 90 cm superadobe bags very soon.

    Keep on the good work and the enthusiasm flowing!

    Cheers,

    Andre M., architect
    Kallipolis Architecture
    São Paulo – Brazil

  8. In farm country those are commonly called pole barns. Sometimes just a roof, sometimes a side or three to protect from prevailing winds. You get great rain catchment from the large metal roof that can be collected and used during construction. Covered porch when you are done. Even in rural building code areas, pole barns may be exempt if used for animal shelter–a milk goat is cheaper than a permit!

    Nez has it right.

  9. Owen, I hate to throw rocks, but couldn’t you accomplish the same exact thing by simply buying or even renting a large party tent? I mean, we’re talking thousands of dollars here.

    If I’m careful and I use recycled materials (like SIP “scraps” and “B” stock) I can build a pretty large roof (that’s even insulated) for much less.

    We just put a SIP roof on an ISBU home (28×44 – [3] 40 HQs) for less than $2 grand.

    Set me straight, huh? What am I missing here?

    • The general concept of providing a permanent roof with wide roof overhangs is very practical. There are lots of design possibilities. This is just one example. I just updated my comment at the end of the blog post to better explain some of the benefits.

        • Maybe you can get a better price in your area. Or maybe you prefer SIPs or another type of roof. You’d get the same benefits. In our area, for instance, it’s killer hot in the direct sun. Working in the shade is much more comfortable. Taking this discussion a step further… roofs are almost more important than walls. Maybe that’s why George Nez focuses on “roofs first.”

  10. Thanks so much for this blog. My husband, my three young boys and I are hoping to build our own (debt-free) earth bag home in the northern lower peninsula of Michigan in the next few years. Your information is very helpful in this planning stage that we are in.

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