Cob Oven at the Wildflower Home

I was invited to teach a cob oven workshop at the Wildflower Home, a center for young mothers in crisis, whose mission is to help lead these women towards self-reliance.

I was quite nervous to be teaching in a foreign language, but it went quite well leading by demonstration and the women had a total blast.

Part 6: Thatching

Peggy teaches us about the local grasses used for thatching. This is by far the most common way to roof your home in this part of Thailand.

The grass is wrapped around a piece of split bamboo and tied tightly to it.

We use strips of bamboo to fasten each section of thatch on to the roof framing.

We thatch from the bottom up, each layer is about 4 iches above the previous row.

Thatch is a great way to roof in the tropics because hot air that accumulates in your home can natural vent out, while any rain that hits the material will run along the blade of grass and drip along the edge only. This system lasts quite long, the thatch will only need to be replaced about every five years.

Part 5: Roof Framing

the roof takes shape

sitting on the top of the wall while installing rafters

Jackie, adding notches when needed

the framing is built directly into the mud brick walls

Part 4: Reclaimed Wood Floor

spreaders buried at the end of each joist

leveling the joists

fitting each floorboard

packing the space behind the blocking with clay straw

a beautiful reclaimed wood patchwork floor

Part 3: Arches

Probably the most fun aspect of using adobe is building arches. These make great door and window openings. And they the surprisingly strong and can bear a lot of weight. First, build a wooden form and support it at the level you want to start the arch. Then as you build arch the form, use a string attached to the center point to keep track of each brick's alignment.

You can also use stuffed bags to build a form.

In the case of our largest arch, that worked just fine!

Testing them out once they are dry is so much fun!

Part 2: Making bricks and Walls

Welcome to the mudpit! The great thing about adobe bricks is that it's really easy to make the mix. You can use the clay in just about any hole you dig on the property and since we will be using a form to make the bricks and letting them dry in the sun, we don't need to worry about too much moisture in the mix. Thus, the pit becomes a creamy slurry and only requires simple walking around in it to mix well. This is also the same way we mix the mortar! For the brick mixture however, it is good to add a fiber component if you have one available. Adding fiber such as straw will increase the strength of the bricks and also make them more light weight. We added rice husks once we could get them.

Each brick will be 4 x 8 x 16 inches, so that we can use them in a variety of different positions. Packing the mud into forms...

Staring to lay the courses...

And probably the hardest part of it all... getting the bricks from the brickyard to the building site! We make it a group effort and have about 30 minutes of passing brickis on a 'brick line' each day.

The building takes shape!

Adobe Home for Peggy & Jo -- Part 1: Foundation

Pouring your own foundation isn't as hard as it might seem. Here we created our foundation in less than a week. First we cleared the site and leveled the footprint area. Then we tamped the earth solid using garden hoes and a big log with handles attached to it.


Then we marked out the wall's locations using a peg with a rope attached for the circular portion of the house and the pythagorean theorem (a^2 + b^2 = c^2) for the extensions. We set up battens with string to mark the edges of the walls and then excavated a trench 15cm deep for the footings. (No need to worry about frost-heave here!)

In Thailand, plywood is a precious commodity, so we built our forms for the foundation stemwall using old adobe bricks lined with feedbags. What's great is that they support themselves so no hardware is required and they can be reused for building with later.

Then came the not-so-fun part, mixing concrete, but it can be fun if you have a lot of people and don't have too much to do of it. We set up a bucket brigade to supply the right ratio of sand and gravel that we would add to the cement. Onward!

Once the concrete was thoroughly mixed, we poured it into the forms. The next day, we removed the bricks and two days later we'd be building walls.