Loading a kiln is one of those jobs that looks simple until you have a shelf of glazed pots in front of you and a lid waiting to be closed. Get it right and your glaze melts the way you hoped, your bisque comes out sound and your elements last longer. Get it wrong and you can end up with a shelf of pots that are scorched on one side, underfired on the other, or welded together at the rim. The good news is that even firing is mostly about two things: airflow and balance. Everything below is about giving your kiln the best possible chance to do its job evenly.

Even Firing Begins on the Shelf

Before you load a single pot, check that your kiln shelves are clean and freshly coated with kiln wash. A flaking shelf can shed grit onto glaze, and a bare shelf invites glaze drips to fuse permanently to the surface. Once a shelf has a run of glaze welded to it, that bump will lift every pot you stack above it, which throws your whole shelf height out of alignment.

Wipe the rims of your pots, check the bases for stray glaze, and give every piece a quick look for dust. The way you arrange those clean pots matters just as much as what's inside them.

Leave Room for Air to Circulate

Heat moves through a kiln in two ways: by radiation from the elements and by air moving inside the chamber. If you pack pots tightly together, you block the moving air and you create pockets that heat at a different rate to the rest of the load.

• Leave at least 2–3 cm between neighbouring pots, and more between larger pieces.
• Keep glazed ware slightly further apart than bisque. Bisque can be loaded more densely because it won't stick to its neighbour if it touches.
• Never let two glazed rims or two glazed bellies touch — glaze will fuse and you will lose both pots.
• Leave a clear gap of 5–8 cm at the top of the chamber so heat can move across the front of the load rather than pressing against the lid.

If you are firing a full load, think of the chamber as a chimney. Air needs a route from the base of the kiln, up past the pots, and out at the top. A solid wall of pots across the middle of a shelf will stop that movement dead.

Respect the Elements

Elements are the single biggest cause of scorched and blistered pots. Anything sitting too close to a glowing element will be hotter than the rest of the load, and glaze on that side may boil, crawl or over-melt.

• Keep every pot at least 5 cm clear of side elements and lid elements.
• Do not lean tall pots towards the wall. Even a pot that starts clear can shift or slump into the element zone as it fires.
• Skip the outermost ring of a shelf for anything precious. That is where the heat is fiercest and where your best glaze test will look nothing like the rest of the load.
• If your kiln has grooves holding the side elements, remember that heat radiates sideways. The wall zone is hot, not neutral.

The very bottom of a top-loading kiln is usually the coolest zone, and the top is usually the hottest. Load your most forgiving work — bisque, test tiles, robust stoneware — into the extremes and put your prize pieces in the calmer middle.

Stack Shelves Like a Well-Balanced Tower

Shelf placement is where careful potters separate themselves from hurried ones.

• Use three supports per shelf, arranged in a triangle, not four. Three points are stable on an uneven kiln floor and won't rock.
• Line the supports up vertically from shelf to shelf. A tower that leans puts uneven weight on the pots below and can topple during a firing.
• Vary the height of your stacks. Half shelves and staggered props let you fill awkward gaps and keep the load from becoming one uniform, dense block.
• Put the heaviest, widest and tallest pots on the bottom shelf, where the weight is supported by the kiln floor rather than by a prop.

Avoid building a single tall stack in the centre of the kiln. Balance the load around the chamber so heat rises evenly rather than funnelling up one side.

Load for the Kettle You Actually Own

Every kiln has its own personality, and it is worth firing with a set of pyrometric cones on each shelf, at least until you know your chamber well. Cones will tell you where the cool and hot spots really are, and that knowledge is worth more than any general rule.

A useful approach is to load slightly more densely at the bottom and around the edges of the chamber, and more sparsely at the top and in the centre. If your kiln fires hot at the front, keep the front third a little emptier. Record what you did — a quick sketch of the load with the firing result written on it will guide your next session far better than memory.

Before You Close the Lid

• Check that no pot, prop or shelf is touching an element.
• Make sure the lid sits flat and the kiln is not overfilled to the point of pressure on the top shelf.
• Confirm every support sits squarely under its shelf, with no overhang.
• Look down through the chamber one last time and ask yourself whether air could move freely from bottom to top.

Do that and you will close the lid knowing the kiln has the best chance of delivering the even, predictable firing your work deserves.