Ferrocement is resource efficient because it uses minimal rebar and concrete to produce ‘thin shell’ structures. The resulting curved members are somewhat similar to trees and plants. This is the opposite of straight concrete walls that rely on massive thickness to gain strength (and cost way more money).
One of the best sites for learning about ferrocement is Steve Kornher’s Flying Concrete website. Steve has gone to great lengths to provide lots of photos and detailed information about ferrocement.
Ferrocement can be used to create many things, including boats, cisterns, stairs, and roofs on earthbag domes and earthbag vaults.
Well it is now five years later…
Has this subject slowly withered away??
There does bot seem to be any further discussion….
As far as I know this guy is a full time contractor building houses. Go to their site for details.
What thickness is ideal for a ferrocement wall?
It all depends on the size of the structure, span between supports if any, shape, etc. His website provides many more details to help determine what will work in many cases.
Am in Africa Kenya do you have those who fund to build for needy widows
As a graduate architect and past concrete contractor and boating enthusiast, I recommend looking @ the methods of boat building and using some of them for your houses. Domes can be built w/o staging. The trick is relatively fine reinforcing and shape forming rods tied together with wire. the mesh is filled with concrete applied by two people, one inside and the other outside. One applies the concrete by pushing it through, the other smooths it on the other side. The strength comes from the compound curves, not the thickness. It works for sea going boats and they must be much stronger than a building.
Very true. What’s the best book in your opinion for do-it-yourselfers who want to make their own ferrocement roof, etc. It seems simple enough, but the last project I saw was a total failure, because they didn’t use proper techniques and get it completed before heavy rains.
Ferocement looks lovely in free-form home construction… I might try it myself.. I’ve build several dome homes here in Pacific NW using the plentiful wood as my main material, and conventional construction that gets me past the permitting requirements.
But I have a number of wild ideas for stellated structures for instance that would work well in cement.
Not so good for boats… If you want a material that’s denser than water for boats, just the steel is fine. I’ve heard stories about ferrocement boats that, in salt water, the steel rusts and cracks the cement.
Well, Mike’s stories are just stories. the fact is they perform as designed, built, and maintained. One story of a failed skyscraper does not make all of them – questionable. Many people get in a hurry to build something and without a plan and materials at the start an build something that fails. Don’t blame Noah for running into the mountain someone drained the tub.
Look at the watts towers. One mans recycled materials and they tried to pull it down and could not. Concrete and steel are a composite of the oldest materials on this earth. Many ferrocement structures and especially boats sail the high seas, crash on rocks are pulled off, and sail away to new adventures. The key is to design and build with the purpose and fitness as intended.
I live near Tucson AZ and I am interested in getting engineeried plans for a ferrocement house. Or getting in touch with someone who might be able to “engineer” a set of plans for me.
Thanks,
-Mike (Vail AZ 85641)
One engineering firm that is licensed in most states and is conversant with many alternative building techniques is Nabil Taha at http://www.structure1.com
hey mike, draw your own, and go to a pole barn engineering firm, and have them modify it to “make it work” engineering-wise. it’s all “hollow box construction”, not difficult to run math on the shapes today.
I thought I would throw in that link to the Cal Earth Photos I took in 2005. Hopefully it will help those interested in ferrocement vaults.
http://s1261.photobucket.com/albums/ii594/Milton1960/
I just added the link to a comment about the easy way to make ferrocement roof panels. Lots of people are saying they want more info on ferrocement.
It would be nice to find a ballpark figure on the price per square foot when you build with ferrocement, and if there are any “norms” for working with it; size of rebar, distance between the rebar, etc.
Steve has pricing info on his Flying Concrete site. Someone has already mentioned that the information may be out of date. Try contacting him to see what the latest figures are.
I love what can be done with ferrocement!
More on this subject coming soon.
I stumbled upon this site a few weeks ago. As Owen knows, I have been trying to find an inexpensive way to build a home for my family. My wife fell in love with some of the vaulted buildings on the Cal Earth site. Every since then I have been trying to figure out a way to duplicate them and still have the cost savings, fireproof, impact, wind, and quake benefits of an earhtbag build. I love Steve’s buildings, i just wonder the actual cost in todays market, as the cost listed seem to be from 2005.
I do want to say that until I found Owen’s, and also Kelly’s sites, I didnt think it would be possible for my family to own a home without going in debt until we are in the grave. We are in the process of trying to find a place to move that will allow us to build with earthbags. I am hoping that all this will come together at a price that we can manage, but Im not sure. As of now I am looking for a job; I will graduating with a Bachelors in Science majoring in Accounting after this semester, but have yet to be able to find work here in the Shenandoah Valley of Virginia. I am not the typical student, I am a 41 yr old, father of two, married to my wife of the past 19 years (only one,lol). We are hoping that the life changing injury that caused me to return to school will turn into a positive event for our family, finding a less expensive way to own a home would be one of them. Kelly and Owen, thank you for all you do on your blogs, they are needed!
Try emailing Steve for an update. He sounds like a good guy that wants to help people.
I visited Cal Earth when the vaulted house was being built. They used a vault form with 6×6 wire. The stabilized earthbag walls were built to a height of 5 ft.. Each vaulted room had it’s own wall, so that the walls between the rooms were 2 bags thick. The vaulted ceiling was form was set up between the walls with the wire stretched over the form. Stabilized soil was layed over the wire and on top of the form. I believe they may have used a gunite machine eventually. All of Cal Earths structures used soil stabilized with cement. 7-10 % I think. The width of each vaulted room was 12ft. They were trying to use tubing for the vault, but I don’t know if it worked on large spans. I have a few pictures. Owen If you email me with an address, I will send you the Cal Earth photos.
Thanks for the details. My email is at the top of the page under About Us.
What is 6 x 6 wire, and can you define “stabilized earth bag and soil”?
6×6 wire is also called remesh or reinforced mesh. It’s commonly used in driveways to strengthen concrete. Here’s a photo with remesh attached to rebar: http://www.google.co.th/imgres?q=6×6+remesh&hl=en&sa=X&tbm=isch&prmd=imvnsb&tbnid=HUCQchq-Ima06M:&imgrefurl=http://www.forestryforum.com/board/index.php%3Ftopic%3D47941.60&docid=FawmwVBgI4xBgM&imgurl=http://www.forestryforum.com/gallery/albums/userpics/14190/3424/remesh_done.jpg&w=600&h=450&ei=AZ0bT-73DtDIrQfAsvDGDQ&zoom=1&iact=rc&dur=318&sig=100673959461572628440&page=2&tbnh=144&tbnw=223&start=9&ndsp=14&ved=1t:429,r:2,s:9&tx=126&ty=103&biw=960&bih=511
If the link doesn’t work, try this one: http://www.hutchison-inc.com/html/fence_wire/misc/timbermesh.php
Or just google remesh.
Stabilized earthbag means lime, cement or something similar has been added to soil to make it harder and more water resistant. For instance, you can add enough stabilizer that earthbags can be submerged for extended periods of time. This would be good if you’re in a flood zone or heavy rainfall area.
I just found this new technique (new to me, anyway) for making ferrocement roofs at Steve’s Flying Concrete site. He shows how to make panels on the ground so you don’t have to plaster overhead. This eliminates the most difficult and awkward step of making ferrocement roofs. The panels can be hoisted in place by crane or with a crew of strong workers. I think I’ll turn this into a separate blog post because it’s so exciting. Check it out. http://www.flyingconcrete.com/roof-panels.htm
Now you’re talking. I have been familiar with this site for years, and recommend it. I feel that it’s technology is an ideal way of creating a permanent, fire-proof, etc. roofing structure, tied into earthbag walls.
Yeah, we should emphasize ferrocement more often. Roofs are often one of the most difficult and important parts of building a home, and ferrocement is a great choice. Ferrocement makes it practical to create really unique designs without breaking the budget.
Steve is really a sculptural artist who works with buildings as his form. The picture is from a work in progress in the little village where I live in Colorado. It was initially intended to be a storage vault for books, but I suspect that it will eventually be lived in; it is way too beautiful just for storage.Steve usually works with lightweight aggregate, so that the structures are comparatively light and more insulating that normal ferrocement.