Frequently Asked Questions
Most every topic imaginable about earthbag building and related topics has already been covered numerous times on our blog or one of our other websites. In an effort to cut back on emails, this page explains how to use our new search engine, find answers to the most Frequently Asked Questions, and locate the most popular and useful articles.
Browse by Topics or Date: Scroll to the bottom of this blog.
Kelly Hart’s Earthbag Building FAQ: A compilation of hundreds of the most commonly asked questions. Please read this and other information listed below before sending us personal emails.
Step-by-Step Earthbag Building
How to Build an Insulated Earthbag House
Soil tests: Want to make sure you have the right soil mix for earthbag building? Check out Patti Stouter’s excellent article on Soil Tests for Earthbag.
Popular Articles about earthbag building
Plumbing and Electrical Summary for Earthbag Houses
Building in Hot, Humid Climates
Kelly Hart’s Dome Building Guide
Owen Geiger’s How to Build an Earthbag Dome
How to Build an Earthbag Roundhouse
Earthbag Natural Building YouTube videos
Owen Geiger’s Earthbag Building Guide and Earthbag Building DVD
Green Home Building.com — Earthbags
Ask the Experts – Earthbag Questions and Answers
How do I order earthbag house plans and how much do they cost? (same plans can typically be used for straw bales, cordwood, adobe, etc.): DreamGreenHomes.com
How do I subscribe and get blog posts by email: Sign up in the right hand column of this blog.
Other websites by Owen Geiger and Kelly Hart: See the links in the right hand column of this blog.
When pounding rebar spikes in earthbag walls for support, is it advantageous to pound some at a 45 degree angle?
In some cases this might be true, but not generally.
Hello, I don’t know if all of this information is already written somewhere, but I’m having a hard time finding answers to some questions. My husband left us and our living situation is temporary. I plan to build my children and myself a small earthbag home. I obviously don’t have much to spend on it, but I’m willing to do whatever I can to make it work; I just need it to be safe and dry for us. Is there someone I can send my questions to or pay a small amount for a consultation?
It’s in rural Paraguay. I have questions about incorporating posts into the first layers of earthbags and finishing the walls with wattle and daub. I also have questions about how deep the foundation should go in my area, floor depth, about outdoor patio flooring and paths, and about the order of roof layers. I either cannot find information or find conflicting information and I’d like to feel solid about these before I begin.
Please let me know!!
You might take a look at the free emergency earthbag shelter plans we have available at https://naturalbuildingblog.com/emergency-shelters/
You could certainly incorporate posts into a partial eaarthbag wall and finish it with wattle and daub, or how about a straw/clay wattle wall as shown at https://naturalbuildingblog.com/the-value-of-straw-wattle-walls/
Paraguay does not generally have freezing weather, so foundations can be quite shallow. Recessing the structure into the ground will help keep it cooler. Perhaps you can find someone local to that area to help with some of your questions.
Thank you so much for the quick response! I am taking a look at those resources right now.
My only question about incorporating posts is how far in the ground they would need to be in order to support the roof? Would I tamp them into the rubble trench as well?
Thank you, again! I really appreciate the help!
Unless wooden posts are thoroughly preserved against rot, they should not touch the ground. I would suggest concrete piers that are prepared to attach the wood to them. This is also true of metal posts.
Building with earth in northeast Nevada – rammed earth or earth bags? I would like to build a small one room home, a couple of outter buildings (workshop, small barn) and then a wall around my buildings and yard to keep animals out.
You could go either route. Earthbags have the advantage that they don’t require erecting forms for tamping soil, and they can be filled with a greater variety of soil types.
We have a great event planned including lots of how to build with bamboo!!!
https://www.eventbrite.com/e/358051570887
Oct 21-23 2022 Sebastian FL
I also posted this at https://greenhomebuilding.com/news_miscellany.htm
ive read some comments above… this is not rocket sciience but the process consists of getting your hands and feet wet and discovering (through trial/error which is called learning) that with half a dozen elements in different proportions/mixes/methods one can built s natural house
all this is more than adequately shown/exemplified/done on many hundreds of youtube video clips
listen forget
see remeber
do learn
Ok so when I inquired about the road base used here in AR they said it had everything I was looking for over the phone, however, when we went there in person the guy said the clay content was like 3% and we cannot have any brought in apparently. Is that enough? Or are our dreams of building an earthbag house over?
I suggest that you get a sample of the available road base and perform some tests on it. There is an article about how to do this at http://earthbagbuilding.com/pdf/SoilTests.pdf
Also, when you say 3% Portland cement, do you mean 3% by weight or volume?
volume
In reading forums about EB, I often see something like “you should do a test first”. Can you elaborate on that please? For example, if I wanted to test the differences that the addition of 2%, 3%, 4%, and 5% portland cement made when added to bags, I should build a small wall with this variety of bags in it? How tall should the wall be? How long should the bags sit there before being tested? etc
I suggest that you read these FAQ’s that will probably answer your questions:
http://earthbagbuilding.com/faqs/mix.htm
http://earthbagbuilding.com/faqs/jartest.htm
http://earthbagbuilding.com/faqs/stabilizer.htm
In searching for a supplier for bags, I see that some are described as woven and some not. Some are “regenerated polypropylene” – I am assuming that this means that they are new, but made from recycled materials? Is there a website that has a deep amount of info on this topic? Buying the wrong bags would be an expensive mistake to make.
Regenerated polypropylene can be homopolymer or copolymer loaded with mineral fillers; the regenerated material has characteristics that are very
similar to virgin polymer. In either case the bags are probably made from woven fibers. You definitely want woven poly bags so that they can breath enough to allow the contents to dry or cure.
“homopolymer or copolymer loaded with mineral fillers” Are both OK?
The homopolymer is likely quite similar to the original material and the copolymer with mineral fillers should be benign.
Do you know of any earth bag projects in Tibet? or western China?
There are lots of earthbag buildings in Nepal, but I don’t know of any in Tibet. As for China, I am sure there are some. you might look at https://naturalbuildingblog.siterubix.com/earthbag-eco-village-in-beijing/
Once the house is built…is it feasible to make tiles to cover the exterior of the house using soil and cement? Would pressure be enough to make tiles or do they need to be fired to with stand the environment?
Cement cures chemically and does not require either pressure or firing; so if there is enough cement in the mix they might hold up.
If bags are filled on the ground and then placed, can the contents be tamped before the bag is sealed? and then tamped when put in place?
No… you have to have the bag sealed and in place before it is tamped.
Is it because tamping once in place conforms once bag to the bags underneath and gives it more strength?
Yes, the tamping helps lodge the bag and contents firmly into the wall, seal the ends together, and create a nice flat and level surface.
So…I did a little more reading and thinking…that is one of the reasons why EB buildings are safer in earthquakes? There is no mortar holding the bags together – only the weight of the bags, the barbed wire, rebar and slight curve of each bag as it is stacked on the others? So EB structures will be more earthquake safe than rammed earth or adobe?
Yes, I would say that earthbag buildings, built according to established methods, are inherently safer in earthquakes than rammed earth or adobe buildings.
Hi,
Regarding the material underneath Lime Plaster. Has anyone heard of this and or Tried it? Will the Steel cause moisture and will the reed cause Mold? Is it better to use Polypropylene mesh over the bags and then Plaster?
(Translated with Google, from Swedish to English)
Idealmattan® – reed mat
Polishing directly on wood has been a problematic part for the craftsmen for a long time. Plaster constructions have been plastered and the adhesion to the frame has been solved in many different ways. There are techniques where you have nailed small plugs and studs in the timber frame for the mortar to stick, as well as variants where you attach both birch bark and reeds to the substrate to give the plaster something to “bite” into.
Today, the reed mat with horizontal reed pipes attached to galvanized chicken nets is often the best solution. This gives the same type of result as the old-fashioned reed / wooden beam on the frame, but is incredibly much more time efficient.
History
The Revetering Mat The ideal mat that saw the light of day during the 1920s is still manufactured in the same machine, and with the same technology as at Stockholm’s Reveterings factory. Until the 1940s, rehearsal was a natural part of many masons’ everyday lives, but during the post-war period this type of work decreased more and more and the knowledge about rehearsal largely fell into oblivion.
Manufacture of the revegetation mat The ideal rug which was made in 20 special machines at Stockholm’s Reveering Factory from the 1920s until the closure of the factory in 1975. The last machine was bought in 1985 by Hybo Fasad in Ljusdal and thus saved from scrapping. Thereafter, the production of the revetment mat was restarted with the same reed supplier as before and now under the name Nya Idealmattan.
Production at Hybo Fasad continued until the autumn of 2014 when Målarkalk AB took over all mechanical equipment and all the knowledge they had managed and built on at Hybo Fasad during the almost 40 years they had manufactured and also assembled reed mats.
A tradition that we have now proudly taken over and carry on.
https://www.malarkalk.se/produkter/vassmatta/idealmattan#
I prefer using synthetic mesh because it will neither rust nor mold.
Waterproof concrete option? What is the strength rating of your mix; 2500, 3500, what?
This is beyond our expertise.
I live in the Virgin Islands where cisterns are by law (roughly) a cubic foot of water for every square foot of roof; and since our homes usually sit atop the cisterns, that the homes are built on a concrete slab atop the cistern.
Do the cistern plans for the beach house meet that requirement? If not, can they be expanded? What is the floor that separates the house from the cistern consist of?
The Beach House is elevated with a wooden floor above the ground level. The cistern that is shown for this plan is very simple and has a domed top, but it would be possible to create one with a concrete top.
Hi, i am in the process of building a strawbale house in Spain. The plan was to build a timber frame and use the bales as an infill. As decent straw is difficult to aquire here. I am rethinking my plans. After learning about the R values of Scoria and volcanic it has made me think. Is it possible to use Scoria or volcanic rock as a loose infill in a timber frame construction the timber frame will be load bearing. Thank you in advance.
Sure, you can use earthbags filled with lightweight volcanic stone, rice hulls, perlite, or even recycled polystyrene as infill in a timber frame structure.
Hi we are planning to build earth bag dome home… we need some help. we live in mason county but are looking for land in Thurston county. we never done it before and looking to hire experience earth bag builder to help us from start to finish. we don’t know how the city or county code will be like. please contact me at aijust@01@gmail.com if you are able to help us from start to finish . thank you.
See our Resources page at Earthbag Building.com for a list of earthbag builders and trainers. Also, our blog and books talk about the code and building processes. Kelly has a free dome building guide at Earthbag Building.com. So LOTS of resources here if you look around. And, Doni and Kaki’s dome book is good.
Mr Gieger …
I am interested in your Earthbag Vault house. I plan on modifying if into a small chapel on some property I have in New Mexico. Looking at the vaulted earthbag house may need to have it enlarge leghtwise a few feet to accomodate a Front Entry way out of earth bags. I plan on using a concrete footings and to tie off the rebar for the vault to the footings. The problem I am having is finding complete plans for this building. I t will only have some electric in the wall and maybe some LED lighting in the ceiling or along the area of the loft. In place of the Loft I am thinking of using some type of cross beam to better support the structure.
Where can I acquire complete plans for a Vaulted earth bag house.
Thank you for responding to this post in advance.
Jim Cochran
I sell basic plans, not full blown code approved plans. Those have to be done by engineers and architects licensed in your state. Send me an email and we can discuss it. My address is under About Us at the top of the page.
Thanks to you fantastic work i love iT hopefully you can help us we looking to build in europe with like you saying no codes or les codes to build we love Portugal or spain How can we find this out thank you Sandra from holland
Every country, region is different so you’ll have to talk to your local building department. Most are now online.
I really appreciate the quick responses, y’all are amazing! I have a question regarding arches for doors and windows on a dome. I had planned on doing 3ft diameter half-circle arches using the typical fan bag method but have seen pictures of arches made from continuous tubes. I can’t seem to find much information on this technique, though. Are you familiar with it? Is it stabilized earth or just the typical clay/sand mixture? Do you think they are structurally equivilant to the fan bag method?
They’re stabilized. Build a simple test window first if you want. It’s simple. Or if you’re a book learner then Khalili’s book explains more.
Ok that makes more sense then, thank you.
I hope this site is still active because I have been trying to find this answer. I am planning to build an earth bag building, but to keep space I was hoping to butt the walls along the fence line. Any suggestions on how to water seal the side facing the fence line? That side is not accessible.
I hope that my inspiration to venture into this project does not come to a halt with no options.
Thank you in advance.
Are you sure you can build right up to the property line? Usually code requires setbacks.
If it’s permissible, then one option is to stabilize the bags (add cement to the soil fill material in the bags). Also, try to leave a few inches so you can trowel on plaster as you go. Another option is to set strips of plywood between the wall and fence to help hold the plaster in place for a day or so. Slide the form up and repeat as you go. This may leave some cracks/gaps, not sure.
I’m building a 25′ x 50′ walipini in N.E. Oklahoma. I’ve decided on earthbags as the best solution to enclose a 42″ exhaust fan, 18″ firewood chute and 24″ escape hatch in a small triangular end wall that is above ground. I only need 100 bags, but hours of research has yet to yield an 18×30 polypropylene bags that is well rated for durability and UV resistance… in such a small quantity. The non-bogus reviews on Amazon rate all as substandard. Any suggestions for a vendor would be most appreciated.
Our Resources page at Earthbag Building.com has a good list of suppliers (scroll down).
Thanks for the reply Owen. The Resources page has (1) listings for vendors welcoming small quantity bag orders: the strength and short term UV integrity of the bags is very poorly reviewed; Most bags on Amazon that have good strength and UV reviews are of a smaller size – 14 x 26. Do you have hands-on experience with the bags that you recommend from Trademark? Thanks!
At first we only listed the biggest vendors. Then shipping costs started to skyrocket and people were asking for local vendors so we started adding every company we could find including companies that wrote and asked to be added to our list. So no, I have no knowledge of these companies except 2-3 of the biggest ones, plus I have no financial interest in any these companies.
We always recommend that readers buy a sample so you can test the material. Make 1-2 test bags and tamp them really hard to see if they burst. Measure the outer dimensions after tamping.
It’s good to have different size bags and tubes because not every project is the same. For instance, you might want to build a “thin wall earthbag” wall that has rebar and/or post bracing.
I’m making my bags out of vapor barrier rules.
Not sure what you mean. Do not use bags with plastic linings or they will not dry properly and harden.
I’m in Central Florida and would love to build an earthbag home, but have many questions. If I use a liner between the bags and where it’s bermed, will I be able to use the coolness of the Earth to regulate the inside temp? I’m looking to do cooling tubes, if possible, that’ll go through the berm and cool. Is there any way to prevent the moisture from getting to the bags if there is a hole, from the tube, in the liner?
I have tried to find information on earthbag homes built in Florida, with not much avail. I know there was a dome being built in Gainesville, but there isn’t much info on it.
Florida has some of the strictest codes in the US so it would be very expensive and difficult to build there with alternative materials such as earthbags. Engineering fees and codes would gobble up your budget.
Yes, you can add multiple layers of plastic in the berm to divert water. Earth tubes are not recommended in humid climates because of mold issues. Use other strategies. Search this blog for two previous articles about low cost ways of passive cooling: Passive Cooling Strategies (use wide roof overhangs, roof insulation, high ceilings with ceiling fans, etc.)
Hello Owen sir,
we are thinking to build a hyper adobe structure in India. But we are not sure about how to render it. I don’t think the cement goes well with the mud and raschel bags. Do they stick? What can I add to the cement to make it stick together with the mud?
Most earthbag builders use cement plaster, especially in rainy climates that have lots of insects. Build wide roof overhangs and use gravel bags on lower courses. No worry about cement or mud plaster sticking to hyperadobe mesh! It sticks like glue. Way better than regular earthbags. You can use mud to fill the gaps between bags. Then use cement plaster over everything after the mud dries. But do not cover the entire wall in mud (earth) plaster with cement plaster on top because it won’t bond properly.
Hello, an Amazing website you have there.
I am a design student at the Royal College of Art, London and I want to know where I can get pulverised clay in London to buy. So as to start testing some rammed earth techniques. Please advise
You’ll have to search for local vendors. Talk to art teachers, search the Internet, etc.
It’s a shame you don’t have a donate button! I’d most certainly donate to this outstanding blog!
I suppose for now i’ll settle for book-marking and adding
your RSS feed to my Google account. I look forward to fresh updates and will share this
website with my Facebook group. Chat soon!
I would love to know if you know of anyone living in an earthbag home who is asthmatic and how, if at all, this type of home has affected them?
No I don’t. But I do know earthbag homes made with sustainable materials such as earth plaster, wood with natural finishes, etc. are safe. Same is true with many other natural building methods such as CEB, adobe, straw/clay, etc. One good book to check out is The Healthy House by Econest:
https://www.econesthomes.com/
https://www.econesthomes.com/bookstore/prescriptions-for-a-healthy-house-a-practical-guide-for-architects-builders-homeowners-third-edition/
It’s almost time to start plastering but it’s rain rain rain here and even with tarp over the earthbags, the bags don’t seem to stay dry/dry out. Is it okay to start applying a lime plaster (using lime mortar) while the bags are still wet? I have searched and find no sound info on at what stage of the bag moisture is it okay to apply plaster.
Consult with an expert in lime plaster.
Okay, let me ask this way. Can the bags be plastered while freshly laid? I’m sure this is something you’ve encountered. After laying your bags, how long do you wait before you begin applying the plaster?
I have the same question…How long to wait until the plaster coat can be applied. Its nov 14 in Milwaukee and I am still damp with 3 days of 60 degree weqther ahead of me. Can I plaster over damp bags?
Just an opinion based on your experience is fine…
It’s best to wait until the bags are dry.
Thanks for the advice…we took it and waited. We were then blessed with yet another stretch of warm weather in late November 2016 and finished the project!
https://www.youtube.com/watch?v=A8Uybd1zqjg
Amazing! I plan to publish this on our blog soon. Thanks for sharing.
Hi Owen, I have been working with good earth Nepal building an earthbag school. I’m looking at a cheap improvised method for doing a septic system. Do you have any recommendations? Also do you have an email address I could send a septic plan that I have in my head for you to see.
Regards,
Ewen
It will be hard to beat the cost of standard septic tanks in developing countries…
Hi owen, how to you compare earthbag vs earthbricks? I see earthbag being better in most ways
That’s what I think is true in most situations — earthbags rank more favorably. The only downsides to earthbag would be the thick walls in urban areas where every square foot counts. Also, some people want to see the beauty of exposed earth bricks or adobes versus plastered walls,
Hi Owen,
Im about to start working with good earth nepal. Is it better to use a lime plaster on earthbag or will that aid deterioration of the bags?
Ewen Beard
Usually what type of plaster you use on earthbags doesn’t matter if there are good sized roof overhangs. The earthquake risk in Nepal however calls for cement plaster for its added strength. Some remote areas will have to use earthen plaster due to the difficulty of transport and the high cost. Do the best you can in other words.
Please keep us posted of your work there. I really look forward to getting news of projects in Nepal.
Hi, I really appreciate your website and information! We are building a bermed earth-bag round house with a living roof. our foundation is a rubble trench and we will do 3-4′ double bags of gravel on top of the foundation. Then crushed limestone in the bags to make up the rest of the wall height to about 9′ tall. the circle will be about 50′ in diameter. how many buttresses should we use internally? or do we not need them because it’s a circle? thanks for your time.
33′ is about the maximum for a roundhouse before you need buttresses or other type of reinforcement. See this plan for instance:
https://earthbagplans.wordpress.com/2010/09/04/33%E2%80%B2-10m-roundhouse-2-bedroom/
You can go larger if you add buttresses as you point out. The spacing will depend on various things such as the soil test (soil below the house), wind, window and door sizes and locations, snow, codes, etc. It’s best to get local advice on details like this. Keep in mind that interior walls can serve as buttresses if built as a shear wall. Search this blog for the keywords shear wall.
How do you manage the pipes from shower drains in relation to a gravel trench foundation?
All plumbing typically runs through a steel pipe or ‘plumbing sleeve’ that goes through the gravel trench under the earthbags. This makes it relatively easy to replace or repair pipes later.
Is 800 denier sufficient for the poly sacks?
Order one bag and test it. Fill it with the subsoil, etc. you plan to use. Tamp it as hard as you can for a few minutes and see if it bursts. That’s the best way to be sure they’re strong enough.
Is it possible to affix a wall plate to the outside of a bond beam with some kind of bolting system to allow for a separate porch roof to be attached?
Sure. That would be easy to do.
Hi Owen
Us in the Caribbean again :)
Nearing starting our project and very exciting. One thing we are very unsure of at present is how to manage window installation. We will either have round or square windows and are not sure how we can install them into the walls, plus the burglar bars (which will be custom made to size but we are not sure how to attach). If we have square windows we will want to have wooden frames and shutters on the outside. The windows will not have any glass. We are totally stumped about how to do either of these options, no matter what we read about bucks and forms etc.
We just don’t understand how it works when you remove the forms and replace the window and how the window becomes stable in the wall. We have read so much about it but cannot seem to come to a working understanding. Sorry for our ignorance!
Thanks for all your help
Imani
The main process is similar to windows in any other buildings. It might help to get an illustrated carpentry book from the library.
In most cases there is a permanent buck, also called a rough frame that’s installed first. See my ebook for details. You can add metal anchors and/or vertical rebar pins through the buck and into the bags.
The bars can be pre-installed in the buck before mounting in the wall. Or you can add bars between earthbags as you build the wall and omit the buck. So there are different ways of doing things.
New builders: build a tool shed or something small to help learn.
Hi,
I’m planning an earthbag build on a plot in Zambia. I have created a design requiring some of the exterior walls to meet at 45 degrees rather than 90 degrees.
Is this feasible, and could you pass on some advice on the best way to approach this problem?
Many thanks
That will work. Simply fold and stitch the ends of bags at an angle. Remember to use factory sewn bottoms of bags where they face outward on corners. Tubes are faster and easier. Ends of tubes can be twisted and folded under.
Dear Owen,
Many thanks – You’ve reassured me greatly! :oD
Keep up the excellent work!
Hi, I’m in northern IL and want to build a pallet barn for a cow, a pig or two… I didn’t understand how you secured the scrap 2x4s to the foundation. Do you have some more pictures you could email me? Also, what kind of non-concrete foundations would work for us, if any? I have good building skills, just in need of more info/particulars, if you could. Thanks so much!
oh, I forgot too – I love the pallet house and the roof trusses! We would prefer to build with a gambrel roof, would that be possible with the pallet walls as long as we use lumber long enough to span? and, is there enough strength in pallet walls etc to put hay up there? If not, how much reinforcing do you think we’d need?
Sure, if you build correctly. In general, you can use any type of roof you want, although living roofs are a separate case because they’re so heavy.
I’m out of country and busy now. But if I remember correctly the answer is very simple. Just attach sill plates (boards) to the foundation with anchor bolts. In this case the sill plate consists of short lengths of wood that fit inside pallets. Slide the pallets over the sill plates and add screws from the sides.
Hi Owen,
We were planning on building the hyperadobe earthbag method. We won’t be able to work on it everyday,my husband is a truck driver in he comes home for about a week a month and I ride with him. What do you suggest for covering it from harsh weather when we are gone?
I suggest building very small and designing the home so you can add on later in stages. This is easy to do by building half height buttresses where future walls will go. Keep everything tarped the best you can.
Hi Owen
Thanks for all your help so far. We are just about to approach planning authorities here.
I’m foreseeing a great deal of trouble in response to the rubble trench foundation. We are wondering whether we should put in our application with a concrete grade beam. I found this on the internet and wonder what you thought of it:
Seismic regions require more attention to the
> anticipated behaviour of the walls and the overall structure during ground
> motion. I agree with Richard Walker regarding the shear wall being founded on
> a concrete foundation. But, this could be a reinforced concrete grade beam on
> top of a stone rubble filled trench.
> However, the idea of the structure floating on a rubble filled trench in a
> seismic zone is that the stone rubble will allow the building to slip and
> slide at ground accelerations that are much less than the peak acceleration
> produced by the earthquake. This means that the forces in the building walls
> are much less than they would be if the building were restrained from slipping
> by building on top of a conventional foundation. To make this work properly,
> however, the building has to move as a whole, which means, the building needs
> to be founded on a slab of concrete, or a continuous grade beam that is strong
> and stiff enough to make this possible. The basic idea behind the seismic
> advantage of the rubble filled trench (actually, a gravel filled trench would
> work better) is the coefficient of friction. The coefficient of rolling
> friction of a flat concrete surface on a plane of gravel is relatively low. To
> make this work properly, the coefficient of friction needs to be the same at
> all locations under the walls. If the coefficient is different at one corner
> of the building than at another, the area with the higher coefficient gets
> hung up and there occurs differential movement of the structure, causing
> stresses in the walls that could do serious damage. The best bet would be a
> flat slab foundation with rounded edges that would not dig into the foundation
> rubble if tilted. The building would move as a whole and there would be no
> differential wall movement.
The difficulty of getting a building permit varies widely depending on your codes and the building officials. On the first trip I would just ask for a packet of information for owner-builders. Then study the materials and try to learn as much as you can. Working with a local architect who does green building projects will make things much easier. They already know how to ‘play the game’.
The above information about earthquake resistant foundations makes sense to me. But you’ll need to have it engineered to meet your codes. The engineers will figure out the details.
Thanks. In that case, do you think you could get away with a shed roof if it was connected between a concrete bondbeam on a concrete wall and a concrete bondbeam on an earthbag wall? Do you think it would matter which wall was the higher?
Both would work. Provide adequate roof overhang so water doesn’t splash on the walls.
Is it possible to connect earthbag walls to concrete walls through the use of horizontal rebar? Would they need any kind of barrier between them other than the bags themselves?
Sure. It would be easy to connect them with rebar. No barrier is needed unless the concrete wall is getting wet. (Concrete wicks moisture.)
Hi there
Still designing our earthbag house for here in the Caribbean.
How do you approach wallplates for veranda roofs? We are having a veranda around the entire perimeter to avoid water damage to the walls. However, we don’t want it in the same material as the roof. It will also be flatter than the roof so we don’t want to just continue the roof over the veranda. Do you have any advice regarding wall plates or do you have any other suggestions?
many thanks
Imani
Talk to local builders for the best way to do things in your area.
Hi Owen,
You mentioned in faq we can use earthbags for interior walls. Is it possible to add less dirt to a bag to make thinner walls for the interior and it be stable?
Earthbags take up a lot of space as interior walls so their main advantage is bracing in earthquake zones.
Better in most cases to use thin walls made of recycled wood, pallets, CEBs, bamboo, etc.
Thin earthbag walls will be unstable.
Dear sir
i want to build house for my Mum in kathmandu Nepal two rooms. How much does it cost to build
many thanks
raju
Go to our FAQ page and read the article about How much will my house cost? Basically, it’s impossible to say without creating an accurate cost estimate using local costs. Get a cost estimate book from the library and create a spreadsheet using local prices.
But to give you an approximate idea, our 18′ diameter roundhouse cost $2,100.
Hi Owen, many thanks for your response.
What do you recommend building internal walls out of? Could narrower bags be used?
Many thanks
Imani
Obviously you want to use narrow walls to save space. I like pallets or recycled wood with straw/clay, CEBs, recycled brick, bamboo… Make sure the rough bucks for the doors are solidly built.
You can even use found wood in the round from the forest. See a recent blog post about half timber construction. I can’t find the link but the photo in the blog post is really cool. It’s from about 3 weeks ago.
Hi
Could you advise on the best earthbag designs for tropical climates prone to hurricanes?
We were thinking of building on a 2′ stone platform. Do you think that would work? What shapes would withstand hurricanes?
Many thanks for your great website!
Imani
Most information on building disaster resistant earthbag buildings is at Earthbag Structures.com.
Building in the round is the best building shape. Domes are prone to leaks since they don’t have roofs, so roundhouses are the best option in my opinion. The wind will blow around the structure instead of building up pressure against it. The weakest point will be the roof. Use the hurricane resistant roof methods developed in places such as Florida.
Those are the basics. The details will depend on your local building codes. Structure1.com can get your building plans permitted.
We have already dug our rubble trenches for the Tower House and then it rained on us and filled the trenches. They have since drained, but the bottoms are filled with muck. Do we have to dig the trenches out more now before backfilling with the gravel?
Yes, you need to dig down to stable soil or otherwise your walls will settle and crack apart. The higher the walls, the deeper the rubble trench needs to be. Also, it depends on the soil type. Some soils are more stable than others.
Where I am going to build (with one of your plans) is in Jeffreys Bay, South Africa. There is NO clay, but a lot of 2 million year old seasand. The whole area is a nature preserve, so I can only take sand that has blown over the wall, not sand on the beach. This means I will have to buy sand. What percentage of concrete would safely bind seasand or white sand? 20%, 30%. I would be grateful to know if anyone else has built like this, and if so what they used.
Around 5% if you use typical earthbags. Do some tests and see what works best. Compare this to Dr. Anderton’s Eternally Solar earthbag method. See previous blog posts on this site. He uses special tubes designed specifically for sand.
The clay (if available) or concrete (if not available) that is added to the sand hardens the entire block, times however many sandbag blocks, so within a year it would be VERY hard to get through, like concrete. Rest your mind, you will not vulnerable to someone cutting through sandbags- if done in the early building stages the whole building would fall on them and the weight would probably kill and definitely injure them, and after a year it would be like cutting thru concrete.
Hey a general newbie question, i couldn’t find this on Google :(
Are earthbag buildings extremely vulnerable to a$$holes with a knife? So, similar to someone scratching your car with a key, can someone just walk past your house and turn it into a death trap by cutting open some bags? (i don’t think stucco is strong enough to prevent this, right)
Stucco is made with cement that’s often 1″-2″ thick. It would be like scratching the sidewalk with a knife.
I saw your video on youtube about thatch roof you said to do the whole roof p was 100 dollars where do I get the material
Materials vary from area to area. Use what’s locally available. Learn as much as you can about locally available sustainable materials and building methods and then design your house with those things in mind.
Hello, I have a question about roofing for a hybrid rectangular shaped or L shaped earthbag home.
I’ve seen where some choose domes, others choose metal roofing and other methods. But I was researching more natural roofing materials and clay shingles caught my eye. In some cultures they have working parties that get together and produce hand-crafted clay roofing tiles that seem extremely durable and long-lasting.
My question is, would it be structurally sound and stand a good chance at keeping water away from earthbags & insulation if rafters were embedded into the walls to support an insulation layer of straw bales, followed by having earthbags form a modest slope over the strawbales where the walls and rafters would be bearing the weight of the roof? I was thinking if enough cob was used to smooth the gaps between tiers of bags for a rounded curve and a concrete plaster was applied, followed by an elastometric waterproof seal (roof only so walls could breathe) that clay tiles could be used as a first line of defense against moisture, backed up by the elastometric sealer and eventually a sturdy plaster.
The shingles would be attached via an adhesive style foam that I’ve seen used on clay shingle roofing videos in Florida (these roofs even stand up to hurricanes). Would love to hear an experts opinion on it. I have no clue if this idea would even stand up to code. Thanks, I’m enjoying my journey in learning alternative building!
Traditional clay roofing tiles are extremely practical and highly recommended. The method you describe is not totally clear and untested. Best to stick to what works. All those layers of waterproofing are expensive.
Hi, Does hyperadobe mesh tubes need a concrete foundation or can it be built like a superadobe home? If it needs a concrete foundation do you know why that is?
Use the same rubble trench, gravel bag foundation with hyperadobe starting when you’ve above the level that can be damaged by moisture.
Hi Owen and all the lovely people building healthy homes. Next year I will be buying your Zero Energy Two plan, Owen : )
My question is: can anybody share experiences with earthbag, cob overlay building in Florida, Tampa or wherever? I’m also looking for cheap land. I have to be able to build and buy land for $40,000 all in.
i.e. building codes, plan approval. Can anyone share their experiences?
I would also need help with building and would supply 2 meals a day : ) – I’ve got pins and plates in my spine, so am better at things where I don’t have to bend, but am physically healthy. This will be the home I go to seed in, and will leave for my children. I’m 54.
Sorry to disappoint you, but you won’t be able to build a code approved house in Florida for anywhere near that price. The low prices you hear us talk about are for non-code areas. Codes require an engineer’s stamp, lots of extra concrete and steel, etc. that will skyrocket the cost. Earth plaster will not hold up in hurricane zones.
I have an exposure of bedrock that I’m considering for an earthbag foundation. The bedrock is smooth and irregularly domed though, and I’m wondering if it’s okay to level out the first few rows of bags by using bags with varying amounts of fill. The variation in bedrock topography around the perimeter would be at most 2 feet with very gradual changes– no sharp drops or rises. Also, if the bedrock is sloping away from the home would I need to drill into the bedrock and insert rebar or could I just rely on backfill to counter any potential slippage? My plan is to berm the walls and top the berm with insulation in order to fend off the frost. I’m in a cold area of Canada.
Thanks,
Mike
Rebar vs. relying on backfill for support: On issue like this it depends on the value of the structure. You could cut corners a bit with a small vacation home or cabin and rely on the backfill. You’d probably take extra precautions on higher value structures like full size homes.
I had a straw clay slip house built for me, and the builder is no longer here. My walls seem to be dropping tiny bits of sandy lime grit. Is this because they did not use enough lime? I was told I could “paint” it with boiled linseed oil, and this would correct my problem, but if I do that, will the wall still be breathable? Does it need to breathe? I live in middle TN, USA, in a forest. Temps do drop close to zero sometimes in winter, and it’s hot and humid a lot in summer – up to 110 at times. Any advice? Thanks!
Hello Owen,
I have learned that my lot is in a flood zone A area. Obviously, it has never been evaluated and would cost me dearly since it is rural land and off grid. My question is what would be the best solution for building an earthbag in a flood zone A area? Are there any ideas or techniques that would prevent flooding if occurred? My one idea is to find out if I could build up the earth bags on a couple of rows, then add flooring beams across with plywood, then build walls on top of the wood flooring? Kind of like the houses on concrete blocks how it is raised above ground. Do you think it would work or would the earthbags cause corrosion on the wood? I am looking to experiment with this idea just to see if it could work at all. Also, with the roofing beams across.. is it really necessary to have a concrete on the top of the earthbags to support the roof?
Florida has very strict building codes. Don’t do anything until you learn about the codes. Most likely the codes will skyrocket the price.
But yes, you could do as you say — raise the floor on gravel bag walls, add a moisture barrier between the bags and wood floor, add the earthbags and then bond beam on top with hurricane anchors embedded in the concrete.
Dear Owen; I have come across this blog and it’s a fantastic source of information for finally start one of my life goals. I have been doing some research and stumbled upon hyper adobe while reading about super adobe building techniques. I am from Chile and all the information I have found for hyper adobe doesn’t touch the earthquake point. Being in Chile, the last big earthquake we had in the surroundings of where I plan to build the house was near the 9.0 Richter. I have read about super adobe being earthquake resistant (10 Richter) but have not found any tests on hyper adobe. Do you know if earthquake tests have been carried on hyper adobe? Could you point me to some sources on where to find more about this? I’m in the point of deciding which technique to use to build the house. Thanks for this webpage and all of the information in it!
Regards from Chile.
They’re basically the same when it comes to seismic resistance. Utilize good building techniques as explained throughout our websites: round or curved walls are stronger, use buttresses and/or earthbag benches at exterior doors, barbed wire between courses, rebar pins down through bags especially next to doors and windows, and reinforced concrete bond beam. The strongest designs use external pinning: rebar pins tied together on both sides of the wall (opposed rebar). See https://naturalbuildingblog.siterubix.com/external-pinning/
More disaster resistant construction ideas are on our Earthbag Structures.com site: http://earthbagstructures.com/
sir:
i am interested to make stabilized earth blocks or perhaps concrete earth blocks. i have read some articles about the different types or kinds of machineries that can produce these earth blocks..
my question is, if we can use these two materials for the manufacture of stabilized earth blocks namely –lahar and or silt taken from the bottom of a lake or river dam.
if these materials can be used. what would be the proportion vis a vis cement or lime as stabilizer in making the earth blocks.
i am interested on these two materials because we have plenty of both raw materials and i hope to help the people living in the rural areas build ceb utilizing these abundant materials.
hoping you can help me with this inquiry, i remain
truly yours,
Vernie D. Fortes
There are thousands of free articles about earth blocks on the Internet now. You can search for specific words such as lahar earth blocks or silt earth blocks, etc. to learn the details you’re looking for. Change the words a little bit until you find what you need. That’s basically what I do for hours a day.
Respected Owen Geiger a very warm Greetings_/\_…Namaste from Nepal.
I am the student of the final year of Anthropology from Patan Multiple Campus,(one of the 3 historical cities, Patan of Nepal.I must do a thesis in other to be certified with Master degree in which i am studying(Final year student in Anthropology). When i was in search of the thesis topic, i had been imaged by this nature friendly, sustainable shelter through internet. Now i am very keen to make sure “Earth Bags Shelter” to be my research topic!
Hence, i would like to be guided to collect the necessary materials to be documented as a research proposal to be ready. Information such as Literature reviews,Articles,Archives and so on which would aid for the research proposal to be ready under your intellectual guidance that you are blessed with_/\_…
Well, for the research field selection, i already found a place at the eastern north side of Kathmandu valley(another historically capital city of Nepal)”The Pegasus Children Project in Nepal”.
Therefore, i would like to make you humble request for the necessary guidance to be blessed on me to carry on the academically new topic to be my thesis first time in the Education of Nepal.
I have jotted down these words after searching in the google but i can’t get the right materials which i could use for it so i am looking forward to be acknowledged in this really exciting sustainable shelters for homeless people around my hometown country Nepal to be their home sweet home utilizing material under their feet by their own hands for themselves with your beautiful warmly blessed upon me_/\_…Warmest Greetings, all the way from the Mount Everest is what currently i could write down above all 3 historical cities of Nepal(Kathmandu, Bhaktapur and Patan)!
Sincerely,
Sunita Dangol
Student from Nepal
Hello. I really like Nepal and hope to visit someday. Our main website at Earthbag Building.com has everything you need. Every major article, test, video, best projects, etc. are there. Make sure you reinforce your earthbag walls for earthquakes. Good luck. http://earthbagbuilding.com/
Hi, except for the bulk bags,we strongly suggest the PP woven bags as the packaging for lots of products such as the potatoes,onion,flour,rice,wheat,etc.,we are a main PP bags manufacturer from China.
I plan to berm into the sides of my dome with earth. When you wrap the walls with plastic before berming is there still a risk of condensation forming between the plastic and the earthbag walls? Or must the plastic be exposed to air for condensation to form? I have some plastic wrapped around an area that is not buried yet and there is usually a fair amount of condensation between the plastic and the wall. This seems like it could be an issue. Thanks for all the information.
Lower earthbag walls should be gravel bags or bags filled with stabilized soil so condensation will not cause damage. First make a rubble trench with French drain under the bags if you get a lot of rain. Build on high ground. Extend the plastic out 1 meter from the dome. Use double layers of plastic if you want. Build swales above the building if you’re on a slope. Slope the ground away from the building in all directions if possible. Raise the floor above grade. Recessed floors are prone to flooding. Make a roofed dome if you get a lot of rain. Our Projects page shows some good examples at Earthbag Building.com.
I live in Thailand near the jungle,i am busy making adobe stones to make house to live in.
When i turn the stone i see already woodworm under the stones.
I m afraid that when i start to build the house there are woodworm ho go whit the stones and eat the walls.
The stones are made from clay sand and rice hulls.
I just Finnish the stones and like to use them of course any info ?
Any info against woodworms in adobe blocks?
greets
Hugo
Ask locals about these worms and do tests to see what happens. Start with a small tool shed, etc. if you are concerned.
what about elevated tank?
It’s often best to make elevated tanks out of ferrocement. For our homestead, we bought a plastic tank and elevated it on recycled timbers.
Hi,
My wife and I would very much like to learn natural building by volunteering our labor in exchange. Most of the workshops and apprenticeships cost $5000 or more per person– we simply cannot afford such a high tuition. However, we are both hard-working, dedicated people and are determined to learn natural building somehow. If you have any ideas or know of anyone willing to educate in exchange for labor, please let us know!
David
Post this on our Bulletin Board page: https://naturalbuildingblog.siterubix.com/bulletin-board/
Keep searching. You can likely find free opportunities where you help for a few days and the owners provide 1-2 meals per day. Some call these barn-raising events. Most owner-builders would love to have some extra help. However, it can be difficult tracking down alternative projects. Most people do not publish their projects. So you might have to do a bit of detective work. Talk to local architects who do this type of work. Talk to natural building organizations. Contact ecovillages, etc.
Hi, I would like to have about 3 earth houses built. Will these be good near a beach? Are u willing to travel to Ghana? Hope 2 hear from u soon. Thanks, J
Yes, you can build near the beach. Adapt the design as necessary. Example: add storm shutters on windows.
I no longer travel or do workshops. Look at our Bulletin Board on this blog and the Workshop page at Earthbag Building.com.
i want to make acompressed earth block machine . can you help me and give me the dimension and block size and mold size
thanks
eid
See the comments from the other day: https://naturalbuildingblog.siterubix.com/more-info-on-compressed-earth-blocks-cebs/
What size gravel/rubble do I need for the foundation trench? I am considering using crushed concrete for both the trench and the first layers of earthbags. Will the angular crushed cement cause hole in the polypropylene bags? If I have to go with river rock is there a concern about it shiifting once the load of the earthbag walls are on it?
Thanks
You can use various sizes of rubble/crushed concrete in the trench. Add some gravel as you go to fill the gaps and help lock it together. Add some more gravel on top to level it and prevent tearing of bags.
NOT SURE WHAT I’M DOING WRONG HERE BUT THE LAST ATTEMPTS TO POST HERE OR EMAIL DIRECT WITH QUESTIONS HAVE FALLEN THROUGH THE CRACKS…
I WANT TO BUILD IMMEDIATELY (FINALLY) BUT IF MY RESEARCH TELLS ME CORRECTLY, WE’RE BETTER OFF IN AN EARTH SHELTERED HOME BUT MY QUERIES ON HOW TO DO THIS ARE COMING UP SHORT.
ARE EARTHBAG WALLS SUFFICIENT OR WILL CONCRETE WALLS BE NECESSARY?
WHAT TERMS ARE BEST TO QUERY TO LEARN MORE ON THIS SUBJECT?
I HAVE TO REVIEW OWEN’S VIDEO & E-BOOK THAT I BOUGHT LAST YEAR BUT I DON’T RECALL IT BEING COVERED.
Earthbag walls are sufficient in many cases. There are thousands of earthbag houses all over the world. But the details of how to best build vary from region to region. Our websites and blogs cover everything you need. Use the built-in search engine and keep reading. If you have a specific question that you can’t find an answer to then find a related topic on our blog and leave a question.
I am planning to build an earthbag dome in a coastal, humid climate about 20 minutes from Galveston, TX. The average annual rainfall is 57 inches. I plan to use a rubble trench foundation with a french drain to daylight. I just read your comment that you don’t recommend domes for rainy climates. Do you feel my climate is too rainy? I’m really set on the earthbag dome, I already have my design and have ordered the tubes from cal earth. Do you have any recommendations for an exterior plaster that would work well in my climate? I was thinking of using a lime plaster and embedding rock like flagstone or something over the entire exterior. Do you think the rock covering would provide protection from the rain? Do you have any reservations about embedding stone into the exterior plaster of a dome?
I know I have a lot of questions but your reply would be much appreciated. Thank you for all the information you provide on your blog, it has been very useful. I have read your book on earthbag building as well.
We recommend roofed domes in rainy climates. That would include Galveston. There are numerous roof options. Conical roofs are best for high wind areas (the wind will blow around instead of building up pressure against it). Our Projects page has a few examples. You could also do a reciprocal roof, etc. http://earthbagbuilding.com/projects/projects.htm
Ask any roofer and they’ll tell you how hard it is to prevent roof leaks. Water finds its way through every little crack. Hint: almost everything cracks as it ages. Materials expand and contract and develop stress cracks. Different materials expand and contract at different rates and cracks develop in between. So building a dome in a rainy climate will require a lot of maintenance. Domes evolved in deserts and that’s where they do best. To me they look out of place in rainy areas.
i would like to know if ANYONE has built an earthbag rain water tank that holds water???? i would like to know if such an idea can be done? what size walls would be needed etc, like one or two bag thick walls? would the structure require plastic sheeting INSIDE the tank before the plaster was applied etc. etc.????
Yes. Search for earthbag cistern.
My husband and I are going to building an eb home close to Houston Tx, and he has a question about the foundation. All the diagrams of a French drain show the pipe in the trench. He is insisting that it needs to be beside the trench because the weight of the house will crush it if it is in the trench. I can see it both ways. If it is only 4 in then the distribution of the wt to the rubble around it will prevent crushing or having the drain beside would work too. He does however insist I get some input. Thank you for any and all comments and yes we are starting with a storage shed.
You can do it both ways.
Now that we have a national building code in the USA will this type of building process be recognized as compliant? I like the idea but don’t know what to think of building codes
There are still rural parts of the US that don’t enforce building codes. We cover this in detail in a previous blog post called Counties with Few or No Building Codes. You can use the built-in search engine to find this blog post. If you don’t want to live in a rural area then you’ll need an engineer to stamp the plans. Structure1.com is the only engineer doing it at this time. Building codes will raise the cost of construction significantly.
So I’m not sure if this sent past time, but I was wondering if it is ok to paint the walls of earthbag walls? Specifically scoria filled ones as that’s what I’m leaning towards.
Paint the bags to protect against UV damage? Yes. Paint the plastered walls? Yes.
I really love the idea of building with natural materials and I’m a little split between straw bale and earthbags filled with scoria. It will mainly come down to cost but one factor is if you can paint the interior of a earthbag home. I know the straw bale house has to breath and I read its good for the earthbag to breath as well but not a must. So what are your thoughts on painting earthbags and/ or are there any ways to paint that would be breathable?
Latex paint is breathable. It will let moisture pass through. Wait until your walls have totally dried.
How well does latex paint and milk paint stick to the bags? Maybe someone can experiment.
I have been doing my best at researching the different forms of natural homes and I am stuck between building with cob or earth bags. I also wonder if it is possible to utilize both for a more natural look than just an earth bag structure.I have come across a few who have done this, just don’t know it would be right for my location. I live in southern missouri where tornadoes (high wind, rain)and humidity concern me when building with either of the forms. We live on a hill top which we considered building our home into the side of, but are on a really tight budget. We have five children so with the amount of people living in the home, it already needs to be a decent size and fear with the size and added construction it would put us above our limit. What type of floor plan would be feasible on a low budget, taking in the weathering factors? I’ve considered dome or cylinder form like in Kansas but I like the look of the Vaulted ceilings and my husband doesn’t like the outside appearance of the dome clusters. Is there a combination form I could use that isn’t traditionally square or rectangular and at the same time, not “too weird” for him? Any suggestions?
Earthbag is much faster than cob. You could see for yourself by building a tool shed or something similar using both methods.
I don’t recommend domes in rainy climates. This has been discussed in great detail in our blog. It would be a maintenance headache and sooner or later the plaster will likely fail.
I’ve always recommended roundhouses as the fastest, easiest shape to build. But it comes down to personal choice as far as what’s most desirable.
do you have any tips on large window wells
https://naturalbuildingblog.siterubix.com/earthbag-window-wells/
How big are you talking about?
My question is regarding insulation and frost and heaving? I live in Northern Nova Scotia, Canada which is a Maritime climate….winters can be freezing cold one week and mild and rainy the next….in the spring the frost can push porches of traditional homes up a few inches. Is there a method for building earthbag in this type of climate I could read anywhere?
There’s a simple, well proven solution. Research frost-protected shallow foundations. The design guide is free on the Internet. Once you understand the basic principles, you can build something comparable with insulated earthbags (bags filled with scoria, etc.). Or if you have strict codes, you can build a standard frost-protected foundation. Either way you’ll save a bundle of money, especially if you build with insulated earthbags.
I would like to purchase the hyperadobe mesh tubes for building an earthtube home in Ecuador. Where can I locate a distributor for south america? How can I price compare different distributors? Do you have a price list for this item?
Use google first using keywords: raschel mesh and mesh bags and the name of your country. We also have some suppliers on our websites. Search this blog for keywords: raschel mesh and mesh bags. And check EarthbagBuilding.com Resources page: http://www.earthbagbuilding.com/resources.htm