My Experience Building a Gas-Fired Kiln for Ceramics

Hello everyone! I recently moved my studio and, with the new space, decided to expand on my old kiln by building a new one from scratch.

The Design

In the post  mentioned earlier, I wrote about sizing gas-fired kilns and
used those calculations to size the new kiln.
In short, I wanted a kiln measuring approximately 90 cm ×
90 cm × 90 cm (width × length × height), firing up to cone 6.
Using insulating bricks, I decided on 4 atmospheric
burners.

The roof was the highlight of the design. I departed from the usual arch construction and used Nils Lou’s flat-roof solution, which is simpler to build.

Reading The Kiln Book by Frederick Olsen—and especially the excellent The Art of Firing by Nils Lou—was essential for me. If you are interested in building your own kiln, be sure to read them!

Here are the general kiln drawings:

As the drawing shows, I used concrete blocks for the base, with 2 horizontal burners at the back and 2 vertical burners at the front.

I made some changes to the original drawing: the roof bricks were set on end, and I increased the chimney height to 2 metres of brickwork plus 2 metres of 8-inch stainless-steel flue. I also placed the damper horizontally at the chimney outlet.

Angle iron and 3/8-inch threaded rods, tightened firmly with nuts and washers, hold the kiln structure and roof in place.

The Construction

The first step was to level the area and lay the concrete blocks. At this stage, it is important to check that the chimney outlet will not meet a roof rafter.

I then began to lay out the kiln’s floor plan with insulating bricks.

For the chimney, I used hard firebricks, which are cheaper and mechanically stronger. I laid them with a thin layer of refractory mortar, since the chimney must have no gaps.

The rest was physical work, requiring careful checks for plumb and square. I also cut the concrete blocks at the front to accommodate the vertical burners.

Then came the most demanding and delicate part: installing the roof. As it was very heavy, I decided to lay the bricks in place. I cut an MDF support board and propped it up to carry the bricks. The surface needed to be well supported and level.

To prevent the bricks from distorting under pressure from the angle iron, I alternated rows in both directions. I used hard firebricks at the corners and a thin layer of refractory mortar on all the bricks. Once they were laid, I installed the angle iron and tightened it firmly with the threaded rods.

I then wrapped everything in ceramic-fibre blanket and aluminium foil. These layers help insulate the kiln and save fuel.

I left all the gas installation work to a specialist company. I strongly recommend that anyone without experience in this area do the same. Safety first!

Conclusion

I think being a potter is about more than forming a piece. It also involves engaging with different fields of knowledge—chemistry, physics, engineering and so on—which in turn can positively influence creative work.

Building this kiln was a major challenge, but it gave me confidence for future projects and was an invaluable experience.

In future posts I will write more about firing the new kiln.

Until then!