T-bricks - the easy way to make an adobe home

Here's an explanation of our adobe T-brick building method. It's simple, easy, and can be done by just about anyone:
http://www.naturalbuildingblog.com/cast-in-situ-adobe-t-bricks

The concept is simple. You make a T-form with scrap lumber or metal, and you pour the adobe bricks right in place on the wall. The form only need to be on the brick for about 5 minutes, then you pull it off, and move down the wall. If you set it up correctly, the forms walk down a wall like a caterpillar, with the end form jumping to the start of the line over and over.

Each course shifts half a brick, so that the space from the forms gets filled with the next course, creating an interlocking brick that's both easy and cheap to make.

We used stabilized adobe, but you could use just about any material for this.

For more photo and description of the method, check out our site: http://velacreations.com/howto/adobe-walls/

that looks like a pretty good system, and very strong as the T's interlock together. Thank you for passing this along.

Ingenious. I love it.

paul

It's amazing how simple things can be and be so good

Not trying to be a smartass but how is this different/better/easier from a rammed earth wall since the adobe is not first dried before stacking, it goes into the wall wet? I like the fact that the mold is simple and the amount of earth moved is smaller increments.

Michael Bushman wrote:Not trying to be a smartass but how is this different/better/easier from a rammed earth wall since the adobe is not first dried before stacking, it goes into the wall wet? I like the fact that the mold is simple and the amount of earth moved is smaller increments.

Well, for one thing, you don't have to ram it! Also, you can add stabilizers like lime, cement, or others and have a weather resistant wall almost instantly. Rammed earth need more substantial form work and additional labor for ramming and sealing.

this is very cool, i like =).

you could do something with stone work in the forms, for a variation.
or more fluffy slip straw or something similar with clay slip, for an interior wall...

How old is your structure? Does it stand the test of time?

Joylynn Hardesty wrote:How old is your structure? Does it stand the test of time?

This structure is now about 12 years old. We never plastered it, but should have, some of the finer sculptural features have eroded a bit, but other than that, the structure is great.

Abe, what are the approximate dimensions of your blocks? Both the T blocks and the blocks from the bolt together forms. I guess I'd also like to get your opinion on the maximum width of wall that is practical.

Bryan

Abe,

Thanks for your article. As a test project for building a home someday we started building a shed last September using T-brick forms. We finally got the roof on this weekend. I had some previous experience with cob and earthbag building from workshops but this was my first solo project. I really liked the T-Brick technique for how simple and how scalable it was. I could work pretty efficiently by myself or could easily accommodate a small crew. Quality control was just a matter of making sure the form you were packing was level. I put together some time lapse videos of our project thus far.

Nice work Aaron. Just curious though, how long did it take you to put up the walls. just the block work?

Joseph Johnson wrote:Nice work Aaron. Just curious though, how long did it take you to put up the walls. just the block work?

Hey Joseph,

There are around 232 total labor hours in the wall. That includes a lot of learning curve along with some child labor and elder labor. I worked on the wall roughly three days(4-10 hours a day) a month over the span of nine months. We could do 1 course (~40 linear foot, 5.5 inches rise) in about a day. By myself it would be a long day. With some helpers we could knock out a course in 6 hours or less. I kept pretty good notes on hours and costs. I'll tabulate them and make some nice graphs and tables.  

We did 5 test bricks 12"x14"x3-1/2" just to see if our soil was good for adobes. We did this at 9pm and the mold was pulled after 20 minutes. at 11am the following day I stood them up on end and couldnt resist taking one and doing a 4 ft drop test. It cracked across the middle but didnt break in half. At noon the next day I broke it in half and found it to be almost dry almost to the middle. at noon the next day I dropped another and it suffered only minor chipping on the edge that hit first. Now these were not stabilized and and the only thing we added to the soil was straw and water. the next day I took one and dropped it from 4ft twice and kinda tossed it out in front of me several feet with no damage. it wasnt until my sister flew into the driveway and ran it over with the car that it got any damage. I know we wont get it that dry and solid so quickly going directly on the wall but I am wondering if 5-6 day between courses would be enough?

Joseph Johnson wrote:We did 5 test bricks 12"x14"x3-1/2" just to see if our soil was good for adobes. We did this at 9pm and the mold was pulled after 20 minutes. at 11am the following day I stood them up on end and couldnt resist taking one and doing a 4 ft drop test. It cracked across the middle but didnt break in half. At noon the next day I broke it in half and found it to be almost dry almost to the middle. at noon the next day I dropped another and it suffered only minor chipping on the edge that hit first. Now these were not stabilized and and the only thing we added to the soil was straw and water. the next day I took one and dropped it from 4ft twice and kinda tossed it out in front of me several feet with no damage. it wasnt until my sister flew into the driveway and ran it over with the car that it got any damage. I know we wont get it that dry and solid so quickly going directly on the wall but I am wondering if 5-6 day between courses would be enough?

I think 5-6 days would be plenty, especially in hot months and if you use a drier mix. I had the week of Christmas off and I was able to do a couple of courses on consecutive days. On the second day one of my lower blocks bulged a bit. I think that was primarily because I used a soupy mix on that particular block. The rest seemed fine though.    

Here my variations on Abe's forms:


I used 2x6s. The interior of all the forms are 12" wide and either 12" or 18" long. I think 2x4s may work better to prevent the block from slumping and to make the forms easier to slip off. The corner form (3rd from the left) was fairly heavy.  

I extended the legs to the full length of the form. This was helpful when I couldn't center the form over the gap.

On the corners of the building I alternated using the first form from the left and the third form from the left.

For the door way and window openings I used the end cap form (far right). Every course I would alternate with a 12" end cap form (not pictured).

Hello Aaron. How is your shed doing, 7 years later? Do you remember the ratio of clay to straw that you used?

Joylynn Hardesty wrote:Hello Aaron. How is your shed doing, 7 years later? Do you remember the ratio of clay to straw that you used?

I was just thinking I should give this thread a bump. Shed is doing great. For ratios roughly three parts sand, 1 part clay and 1 part straw or around 3-4 big handfuls of straw for a wheelbarrow load of cob.

Here is a blog post about some repairs I made in May 2022 and here is the YouTube video:

The pace was slow but maybe that was part of Abe's plan.  Meditation can occur in many types of purposeful manual labor.  Ever go to the gym and see some weight lifters going ballistic with rapid movement, loud clanging, and feral grunts of exertion?  Others gain endurance by slowing down the lifts and easing the weights down with barely a sound.  

Different strokes for different folks I reckon.