Generally, most people who deal with low-cost housing will try to convince you to use indigenous materials. At first sight, that sounds quite logical, but when you try to equip that house according to today’s life style, you’ll get in trouble. Just imagine trying to install electrical installation in a house made of rock or palm leaves. So maybe we should look for other options.

Case 1: This is one system I found looks pretty appropriate for that purpose to me. You basically shape the house out of Styrofoam (eps = expanded polystyrene foam) blocks and cover everything with concrete. Ok, it’s not quite that simple, but basically what it is about.

After having all the underground piping in place, you pour the slab. If you wish, look at the mix mentioned in Case 2 (below) and use it for this slab, to achieve some thermal insulation.

Now you take your eps blocks, probably about 10 cm thick, and practically build your house with them. If the blocks are not tall enough, you can glue them together with diluted paper glue. And if the panels are too tall, it’s easy to cut them. Even the roof, slightly slanted, can be made this way.

After that you make all the cut-outs for doors and windows, and cut ruts for the electrical and hydraulic installation in the walls. Wherever you want to install a box for a switch, etc., cut out the hole, put the box in place with some cement, and temporarily fill it with paper.

In a similar fashion prepare the places where you will have water faucets in the wall, or want to hang kitchen cabinets to it. In fact, in this case you will have to anchor the load bearing area heavily to the other side of the wall.

Now you wrap all the walls with at least two layers of chicken wire, inside and out. About every 20 cm horizontally and vertically push a piece of baling wire through the foam and bend it over the chicken wire, to firmly hold it in place. The chicken wire should hardly make any contact with the foam.

For that you either place pebbles between the wire mesh and the foam, or you can get plans for a machine that makes “wavy chicken wire” from watermortor@yahoo.com. As this guy only charges a nominal fee and doesn’t do this for money, I guess it’s ok to include his e-mail address here.

Now you have to prepare a concrete slurry to “shoot” onto your walls. There are basically two types of equipment for that: gunnite and shotcrete. The difference is mostly if the water is added to the mix and then applied, or if the dry mix receives the water at the nozzle.

There are many appropriate mixes for this purpose, and if you go to the archives of ferrocement.org (a free-of-cost discussion list) you’ll find many ideas. Look for a mix that includes sharp sand, fly ash and fiber.

This house should be one story high only, and therefore 3 cm thickness of concrete should be enough, though of course you’ll have to check the details with an engineer or architect

As you go “shooting” the concrete, somebody else with spread it out and flatten it with a trowel. Let it rest for a month, and then you can add fake brick, flag stone and any other kind of material to make the house look better. In the worst case, just paint it.

Case 2: Now, in some countries you’ll find that eps is quite expensive. In this case look for eps trash. Many stores have a big problem, needing to throw away huge quantities of eps stemming from the packaging material for radios, TVs, etc. Pick it up; it’s gold for you!

Try to find a burr mill or anything that rips the eps chunks into little pieces, without creating too much dust. When you feel you have enough for the volume of your walls, prepare some molds to shape blocks of a suitable size.

Prepare a little of the same mix as above (SHARP sand is crucial for this), add a little dish detergent (to get rid of the surface tension of the water) and add somewhat more than the same amount of eps by volume. Of course you should consult a building professional for this, too, and try a few different mix designs.

Make a few blocks a day, until you have enough for your house. Then build your house like with ordinary cement (cinder) blocks. The roof can be made with approximately the same mix design, but also here you would have to make a few test mixes and consult a professional. And you can finish the house the same way as above.

Case 3: There is an even cheaper way to build your house! Get a huge old top-loading washing machine and fill it half way with water. Now start the machine and slowly, very slowly add paper. As it dissolves it soaks up water and becomes thick. So make sure you don’t add too much paper.

Now add a little dish detergent again, a small shovel of cement, two shovels of sharp sand, and mix for 2-3 minutes. Make tests with different mixes, and then proceed to produce enough blocks for the whole house.

Be careful not to move, vibrate or shake these blocks for at least three weeks, and cast them on a totally flat and sandy surface, so the excess water can run off. In fact, as these blocks are very light, you might want to produce narrow full-height panels.

In any of these three cases you can build high-quality, insulated houses if you don’t take any shortcuts and do consult a professional who is interested in modern construction systems. - If you are really interested in building a house like this, I can provide you with more in-depth information.

Quoting from [adimec]:

 Best article for practical use: thanks a lot

Replying to [curdrice]:

You are welcome! Hope it helps you and others.

Replying to [adimec]:Please Forward more information on low cost housing
Younus Minty

Replying to [adimec]:

A well and usefull article

I have the task of developing jute cement methods for 2300 houses and water containers in Bangledesh. So I reply asking for non esp insulation (too costly) methods. Perhaps bamboo tied between two layers of burlap?? I assume a mold
thanks for any help.

Replying to [Tim Maloney]:

Hi Tim,

Basically any dried, slightly chopped and compressed agricultural fiber will work, provided it won't get wet. Confining it with the help of bamboo rods is a good idea, as it is also a renewable material - basically a tall grass - and in addition is quite resistant to rot under the same conditions.

There is a construction system that involves just that, plus a finish with magnesium phosphate cement. It has to be this kind of cement, as it is the only one that will positively stick to your material and totally encapsulate (water-proof) the filling. It is also about twice as strong as Portland cement. So you would basically create a tough "sandwich" of cement and that soft filling.

All known outlets for this cement are pretty expensive, though the amount of cement needed is much less than what you would expect. Fortunately, by February or March you should be able to purchase it from an American company that invented an improved and cheaper version, so that would cut costs even more.

If that sounds interesting to you, I could put you in contact with one of the owners of that company who I met on a discussion list about alternative construction methods (one of my interests). Just give me a jingle via trade manager.

Replying to [adimec]:Woooo, wonderful election.
I believe for CASE 1 and 2.

However, will the third case work?
It seems so much strange for me. Making the block by washing machine? Can you share me more about this?

My personal email address is: eishimachinery@gmail.com

If it is possible, please write to me or reply here.

Thanks,

Replying to [hamidrezairan]:

Yes, the third case has been tried and proven in the Southwest of the US. Though in the meantime I realized that you can do that as well with pure paper pulp. You'll need a little machinery, though.

Again you prepare your pulp (adding perhaps a little dishwasher soap to the mix), cast it in molds and compress them to get as much water out as possible. You would need a steel mold for this, with a steel screen at the bottom and some kind of support for it. You might need a (hydraulic) bottle-type jack (like for trucks) to operate the press. And you still need to let the blocks dry in a shady place, but soon they'll be ready to be used as building blocks.

Just remember that they don't have very much compressive strength. And whatever strength they have, it's only available as long as the blocks are kept dry. So you'll have to cover (stucco) them very carefully and thoroughly with magnesium phosphate cement. That will give you the garantee that the blocks won't get wet or even moist. Also, consider the possibility of including some pouches with silica gel in the construction of the walls, to wick up any remaining moisture.

The best part about these blocks (aside from their low price) is the high insulative value. On one website a well-respected member claimed that they achieve an R-value of about 5 or higher, depending on the compression. EPS, by comparison, has a value of 4.8. I don't know how to convert these values to other standards, but if you can grasp the significance of these properties, you'll realize that this is extremely good.

My advice always is, if the concept sounds good to you, why don't you run a little test, building a dog house, a garden shed or something similar. That will tell you how to prepare the material and how good its properties are.