Mixing Cob for sustainable building

Quicker than the tarp method and easier on the knees too!
I made this method because my knees and ankles are too fragile for the tarp method.
The clay came from the subsoil in my back garden and I built a shed with it.
Hope muddy and others like it. There is another method to build walls called leicht leim. This one uses just straw and clay. I think the wet straw clay mix is compressed in place into forms and ends up resembling fiberboard.
http://www.networkearth.org/naturalbuilding/clay.html has some details (I have seen it but not done light clay)

Category:

Howto & Style

Tags:

• cob
• building
• straw
• clay
• sand
• sustainable

[dalehodgins]

I wonder have you ever calculated the number of cubic feet per hour that you're able to produce with this method? Is there some reason why you haven't used a rototiller or garden tractor for this process? I've mixed enough brick mortar in a wheelbarrow to know there's nothing easy about the process. Since premixed Cobb has a long shelf life why not mix it in big batches on the ground and put your labor into wall building? Thank you, Dale Vancouver Island Canada.

[gaiatechnician]

@dalehodgins It is super easy calculate the cubic ft per hour. It is a 6 cubic ft wheelbarrow. I also know the capacity of the buckets of raw material. I dug the clay out of the ground in my back garden as I built and I have limited space. I enjoy physical work and it is a whole lot cheaper than renting a rototiller or tractor and then going to the gym afterwards. "Since premixed cob has a long shelf life" I have not found that to be the case, it gets harder every day.

[NewJura]

GT you must have an amazingly strong back!! that hurt mine just watching!!

I still prefer tarp method, I was wondering how your mix was used as it was really wet until I seen that you let it dry overnight, seems doable for a one man show!! great job!!!

[gaiatechnician]

@NewJura When you mix, you cut into the material with the side of the shovel and cut out a 1 inch slice or so of sand/clay. So actually you are just lifting a little slice of material each time. It is like "sculling" in a boat.

AND I used a shovel with a small blade and a half empty wheelbarrow.

There is a lot of technique there! It is not all brute strength and it gets easier with practice.

If the clay/water was well hydrated and like syrup consistancy, it would be lots quicker.

[trailkeeper]

The ratio of clay to sand looked to be about 5 to 7 parts.  The mix being a bit more sand than clay. The fluffed straw "volume"/space-size looks about that of the clay/sand mixture.

[gaiatechnician]

@trailkeeper In this case, my clay was dry and shovels were small. It was more like 2 sand to 1 clay or 2.5 sand to 1 clay. It is coarse sand or fill sand and also the clay had some silt in it. No silt is best.

It all depends. Really good clay might work with 1 clay to 3 sand or more.

[noneedtohaveone]

I know you are a person who tests a lot..because I saw your vids experimenting which solar power and stuff...so

Did you think about using carbon from ,for example, sawdust....I don't want to use a lot of sand and it has a lot of sawdust available in a lot of countries. So I was thinking about gathering the sawdust, burn it and use it so I could use less sand...What do you guys think? pm me please.

[NewJura]

@gaiatechnician I have 2 hydrating pools I use for my clay, they are 5 bales by 4 bales wide with a tarp as a liner and filled with clay and water, they have been setting since October of this last year and the clay is so nice and soft!! I used some in November to build a cob oven for a transition group in town, it was so nice to work!! I tend to use my cob right as I make it so the setting over night isn't an option, you are doing great work GT!!!

[yellowmetalcyborg]

Looks like an intense work out!

lol

Great job, I enjoyed watching, and this is the video I will refer to if I will ever need to make some cob.

[hempseed57]

@gaiatechnician As always thanks for the reply

[trailkeeper]

@gaiatechnician Ok, I'll look up some ratio or parts values. I think I seen a video once where people take that straw and cut it to to small segments.

[muddymuddymuddmann]

THANK YOU SO MUCH! I HAVE LEARNED MORE FROM THIS VODEO ON MAKING COB THAN ANYWHERE ELSE ON THE TUBE. IDENTIFYING CLAY MIGHT STILL BE A LITTLE BIT HARD, BUT I KNOW WHEN I SEE THE STICKEY KIND. IT SURE LOOKED LIKE YOU WERE WORKING IT PRETTY HARD, BUT I BET IT'S WORTH IT WHEN THE SHED IS BUILT. I TURNED THE PLAYER VOLUME UP AND THE COMPUTER VOLUME AS WELL TO LISTEN TO THE SOUND OF THE SAND AND CLAY. WHAT KEEPS IT FROM DISOLVING WHEN IT RAINS? AND AGAIN.. THANK YOU VERY MUCH.

SCOTTY B

MUDDy