How to build a wood fired ceramic kiln

To build a wood fired ceramic kiln of this type is easy. If you want to make a small-scale kiln to build and burn as a solo project or a two-man team, this is a good choice. In the first hour; burn slowly til you pass 150 degrees, this is called candling, and is all about giving moisture time to vaporize from the clay before it reaches boiling-temperature. After that I burn as fast as I can; from 150 to 1000 degrees Celsius takes about 5 hours.

It’s an updraft brick-kiln design, found in many versions around the internet. It’s built in a variety of ways from big to small, and also given a variety of names. I call it the half S-kiln, I guess it’s as wrong as anything else. I find it a bit ineffective, with too much fireplace going on and too little space for the ceramics. First when it’s redesigned to a “full S-kiln” it gets more practical in my mind, but more about that another time.

All the books about building pottery kilns/

I managed to burn it two times before the winter & snow were coming, and now I hardly can wait for the spring so I continue working.

This kiln is easily built with bricks stacked on top of each other with no use of mortar, you can take the kiln down again as soon as the bricks cool down if you want. The design needs some special-sized bricks, something you easily fix with a hard metal saw.

Hard metal saw to cut any kind of bricks

I read that bricks will move a bit (expand) as the kiln gets hot, and correctly enough you will get bigger glitches between the bricks when the kiln reaches high temperatures. Remember to secure the kiln, I use steel wires. I found it to be strong enough to keep this small kiln together.

We built an opening in the back of the kiln to dig out embers blocking the air ventilation under the fire chamber. When not removing embers, keep it locked, you don’t want cool air from the back.

Build a wood fired ceramic kiln the easy way:

What is special about this kiln is its long fire chamber, it has a lot of space for combustion. But it’s hard to see inside if it burns at its full length, or if it has openings and “cold sones” between the fire, leaking cold air up in the wares chamber. It’s also hard to get wood deep into the kiln. I use a 1-meter stick to stuff wood back in there. Throwing short sticks deep into the kiln is possible, better still was firing with thin sticks as long as the fire chamber, and feeding them one by one in its full length. Buildups of embers on the other hand are not a problem, embers fall down in the air ventilation shaft, which you need to remove from time to time.

You want to use an hour or two to pass the boiling temperature of water. The Half S kiln is easily controllable both in the hot and the cold end of the fire range, here I start up with some oversized fire-starters for an hour, keeping ting steady around 80 degrees.

The hotter it gets, the harder it is to increase the temperature. This means the last two hundred degrees can be tuff. Stalling means the kiln won’t get hotter no matter what you try. To overcome stalling and reach your desired temperature; understanding the practical aspects of woodfires and combustion is key. Finding a good fire rate for your kiln is important.

Read in-depth about wood firing and how to reach high temperatures here:

How to burn ceramic consistently in a wood-fired kiln/

Yes, I reached my 1000 degrees Celsius: