In the late summer and fall of 1983, I built my first kiln here in Pittsboro, NC. It’s still standing, 107 firings later! With a big international Woodfiring Conference in Star, NC, “WOODFIRE NC: ENVISION,” coming up May 27-29, 2022, and  presenters and patrons coming from South Africa, Mexico, Finland, Switzerland, Portugal, Australia, Japan, and across the US, I thought would be a good time to share some thoughts and images of the construction of my big kiln and talk about its origins.

The design was inspired by one that Svend Bayer built in 1978. Svend had been apprenticed to Michael Cardew ten years before I too apprenticed with Cardew. At the end of his apprenticeship, Svend travelled to Southeast Asia to look at kilns and big pots and had seen some particularly beautiful kilns in Northern Thailand. After that trip he was invited to build a kiln in Connecticut by Todd Piker, who’s apprenticeship with Cardew coincided with Svend’s. Svend returned to England a year later and established his own pottery near Sheepwash in North Devon, not far from the excellent North Devon ball clay deposits. The first kiln he built there was similar to the first kiln he’d built in Connecticut, but a few years later he decided to demolish it and build one similar to the Northern Thai kilns he’d admired. I was able to visit him while construction of that kiln was underway and was enthralled by the design and later the pots that came out of it. In addition to making beautiful pots, Svend has continued to build kilns, replacing his own on several occasions and building kilns for other people. Now aged 76, he’s built nearly 30 kilns. He’s been a good friend and very important mentor over the years.

So too is Todd Piker with whom I served a second apprenticeship after my time at Cardew’s. The 600 cu. ft. kiln at Cornwall Bridge was the first Svend built and it served Todd well for more than a decade, during years of high production and multiple firings, before the semi-circular barrel arch began slumping and needed replacing. As luck would have it I was there at the time and couldn’t have built my kiln without having demolished and rebuilt the arch of Todd’s kiln. I thoroughly enjoyed that project as well as the higher production at Todd’s, particularly making multitudes of “Harris Bowls,” a 7lbs. hanging planter for nearby White Flower Farm.  Todd had an order for 5,000 of them a year, so we became proficient at making and firing them. One year we fired the kiln 13 times.

When it came finally came time to design my kiln it was Svend’s original Thai-style kiln in Sheepwash that I turned to. Mine has a slightly different floor plan, with straight walls rather than a gentle taper, and because of the configuration of the buildings on my property, a side door for ease of loading close to my workshop door. It was also slightly bigger.

Once Carol and I had moved to Pittsboro, I spent weeks cleaning out the old board and batten-sided chicken house that was to be my workshop, clearing out 6” of aged chicken shit and carting it to what was to become my vegetable garden, cutting out the floor to create the dirt floor which 40 years later is sculptural in its complexity and interest, and underpinning the sills with concrete blocks (it’d been built on fieldstone piers spaced 8’ apart). All the while I was scouting building materials for the kiln shed and kiln and bought cedar posts for the shed from Bobby Roberson in Pittsboro, rough lumber for the frame from Kurt Jones down in Bennet, and salvaged old tin from a large nearby cow shed for the roof.

It was late summer when I started building the kiln shed and kiln and I was new to the sultry South. It was only youthful energy and fervor that managed to get me through the heat and hard labor of each day. The first task was to have a big hole dug for the kiln, kilns need plenty of buttressing and many traditional Southeast Asian kilns are buried in the ground, as are tradition Southern US “groundhog” kilns.

The backhoe operator hit no rocks, only gorgeous Carolina red clay, and must have thought I was building swimming pool. I knew that drainage away from the kiln was vital, I’d heard too many stories of flooded fireboxes, and was lucky to have a site that was relatively flat with gentle grades sloping away on three sides.

I’d never built a building before, hardly knew which end of hammer to hold, and without the help of my kind and patient neighbor, Gene Howard, and endless helpful suggestions from our mail carrier, Keith McMath, it would never have been finished. I dug the post holes, put up the top plates, Gene and I fabricated all the trusses, and with the help of his Uncle Clyde and various neighbors, we had a barn raising, lifting the trusses up, securing them with purlins, and nailing down the rusty old 5V tin roofing. It is 56’ x 24’, and certainly no architectural wonder, but I was pleased to have built a decent and useful structure in keeping with the other vernacular buildings here.

As luck would have it, I managed to find a trove of used firebrick from a scrap dealer, Earl Thurman, who lived just north of the nearby brick-making town Sanford where he’d torn down one of the many kilns. I bought 6,000 of them at 5 cents each. Nowadays used brick are very hard to come by, and new good quality firebrick cost considerably more. The bricks were stacked on rotten palettes on sloping ground, I didn’t think he’d be able to pick them up with his old forklift, but he managed to get them up onto a flatbed truck, which I followed back to our place. Only one of the unsecured bricks fell off as we rounded the courthouse circle in Pittsboro.

Shortly afterwards, the parents of my oldest friend in England, Dave Knappett, came to visit to check up on this wayward venture, and, Charles Knappett, a pathologist, immediately offered to help clean mortar off the old brick, delighting in the etymological connection to his family’s ancient trade, knapping flint. Not surprisingly, he was good at it, tirelessly knapping bricks for three full days, and took a picture of me laying some of the first firebrick.

Mark Hewitt laying the first brick

Digging the foundation of the stepped kiln required careful attention, but the clay made for easy squaring and levelling.

If I was to do it again, I wouldn’t pour a concrete footing, the clay is perfectly stable, and a gravel footer would’ve been fine. Gene helped me throughout, not quite sure what he’d gotten himself into, but intrigued by my enthusiasm and was endlessly kind with his suggestions. That’s Gene in the blue cap.

Hewitt kiln build - pouring foundation

Hewitt kiln build - pouring foundation

Hewitt kiln build - walls

Hewitt kiln build - walls

Once the walls were capped with some tapering  9” x 9” bricks it was time to build the arch form, and again help arrived.

Hewitt kiln build - walls

Stefan Barth, a German, whose father was a cabinet maker, was apprenticing at Cornwall Bridge Pottery and came down to lend a hand. First we built a sturdy substructure, making sure not to hammer nails home so we could lever them out easily later, and wedging in bracing members for easy removal.  Then we made a series of arch forms out of rough 1”x 12” poplar boards, conforming to the planned height and width at each part of the kiln, and created the desired arch profile by turning them upside down, suspending a chain the desired width and height, spray painting the chain, then jig sawing out the shadow.

Hewitt kiln build - creating the frame
We carefully mounted each one and began covering the structure with the ripped tongue and groove 1” x 6” flooring I’d salvaged from the floor of the chicken house/workshop, creating a beautiful, sleek structure that looked like a boat turned upside down. It was a temporary site-specific installation, with mesmerizing internal shadows and beams of light.

Hewitt kiln build - wooden frame


Hewitt kiln build - wooden frame

Hewitt kiln build - wooden frame

Building the kiln - frame

Kiln frame

Building the kiln frame

Now came the task of laying the brick on the arch form, running courses in long rows front to back, using a bedding mortar, when needed, of china clay and fine pyrophyllite grog (a highly refractory mineral mined in nearby Hillsborough, ground into grit of various sizes). The first several rows of brick were “straights”, then came a row of  “#1 arch” bricks to help the bricks conform to the arch. As the slope of the arch increased there were more rows of #1 arch bricks. Finally, the courses of brick met in the middle of the arch creating a herringbone seam of carefully cut interlocking bricks which acted as a series of keystones. Eventually a slender eyelet was all that remained to be filled, and while I used cut bricks to fill the gap, now I would use a good quality refractory castable to fill the small, awkward keystone spaces.

Hewitt kiln build - laying bricks on frame


Hewitt kiln build - wooden frame


Hewitt kiln build - laying bricks on frame


Hewitt kiln build - laying bricks on frame

Mark building kiln

Buttressing the structure came next to ensure the arch didn’t collapse when we took the form out, backfilling with river stone from the Haw and random leftover brick, and adding a concrete skirt to any part of the retaining wall above ground. It’s pretty funky but has done the job these last 38 years. I was still apprehensive about taking out the form, but eventually I summoned up the courage, called Gene, and, starting at the middle of the kiln and working towards each end, we slowly removed the substructure. Finally, as we got to the chimney end, the entire wooden arch fell down with a whomp, missing us and leaving the brick arch standing on its own. What a relief!

Hewitt kiln build - kiln end

Hewitt kiln build - firebox end

Looking down on the Hewitt Kiln 1983

Mark Hewitt pottery 1983

Despite the clear success, for months afterwards I remember having an adrenalin rush that went all the way to my fingertips whenever I looked towards the kiln, convinced that the arch had collapsed while I wasn’t looking.  Subsequent psychological trauma accompanied the approach of the first firing, indeed every firing for years, in the shape of bizarre dreams all pointing to impending doom. Fortunately, they’ve abated as I’ve gotten older, but that doesn’t mean they won’t return.

Meanwhile, the kiln wasn’t finished, we laid 3” of kaowool blankets over the kiln. Kaowool is like fiberglass but made of fibers of kaolin and has a very high insulating value – they use it to insulate space shuttles. We placed wide sheets of tinfoil over the kaowool, and finally parged the exterior with a sand and cement mix which we decorated with red clay, stove blacking, and white cinder block paint. Our brick mason friend, Joe Kenlan and his crew, came to build the chimney, using large kiln car blocks made of fireclay for the hot inner sleeve, and clad on the exterior with common red brick.

Big wood-burning kilns are risky and dangerous to build and fire. I wouldn’t advise anyone to build one who hasn’t had extensive experience beforehand. I was lucky, Michael had one, and Todd had one which we fired frequently, and I had the chance to rebuild.

As I write this, Firing 107 is cooling, I want to go in and see what’s in it, but the temperature is 850F, so I must wait. Who knows what treasures lie inside!

Firing 107 finished - night view