How to Stack a Kiln for a Complex Load

Amelia Johannsen’s portfolio moves between functional pottery, sculptural forms and decorative plates inspired by the Pacific Northwest and Mediterranean coastlines. This mixture makes a busy kiln a normal part of studio life, where a single firing may contain cups, sculptures and table pieces with very different requirements.

The right way to stack a kiln for a complex load begins before the door opens. Clay condition, shelf strength, glaze behaviour, airflow and temperature must all agree. Think of the load as a temporary building: every level should carry its own weight, allow thermal movement and remain stable when heat turns a small error into permanent damage.

Plan the Load Around the Firing Cycle

First identify the firing cycle. A bisque load can include greenware, shelves and decorative forms, while a glaze firing introduces cones, stilts, wadding and the risk of running glaze. Mixed loads are possible, but pieces with different temperature requirements or firing schedules should be separated into clearly labelled groups.

Create a load map before moving anything. Work from the bottom upwards, recording the position, orientation and shelf level of each piece. Use witness cones in several locations and place delicate or valuable work where it can be inspected easily. Leave enough clearance for lids, handles and pieces that expand during firing.

Dry and Inspect Every Component

Every component should be completely dry before loading. Thick walls, handles and coiled sections often retain moisture long after the surface feels dry. Check for cool spots, soft joins and clay that smells damp. In Australia’s variable conditions, particularly through Sydney’s damp winters or Brisbane’s humid summers, calendar time is a less reliable guide than the clay itself.

Remove loose fragments and inspect rims, feet and handles for chips. Keep lids separate when their fit could trap expansion or allow glaze to stick. If a complex piece has been built in sections, the coil-pot construction guide offers useful advice on achieving even walls and dependable joins.

Build a Stable Shelf-and-Post Framework

Kiln shelves support the load; they are not intended to carry tall vessels directly. Use the correct manufacturer-approved posts, shelves and accessories, and check that each surface is level before adding pottery.

Confirm that the kiln is empty, cool and clean.
Inspect shelves for warping, cracks and old glaze runs.
Check posts, stilts and catch plates for damage.

Set posts squarely and align them vertically through the load. Centre dense pieces over supporting posts, while leaving fragile rims and handles clear of adjacent work. Never use improvised kiln furniture or untested clay props.

Space supports to match each shelf’s safe working load.
Keep the centre of gravity low and stable.
Leave access for inspection and safe unloading.

After every level is assembled, view it from the doorway and from above. A balanced load should not lean toward one wall or depend on a piece staying perfectly upright to remain stable.

Protect Glaze and Contact Surfaces

Glaze becomes mobile at temperature, so contact points need deliberate protection. Use kiln wash on shelf surfaces where appropriate, wadding or stilts for glazed pottery, and catch plates beneath forms likely to drip. Avoid placing glazed surfaces directly against one another, and keep any separating material clean and completely dry.

Large plates and shallow vessels need particular attention because their broad bases can rock before firing. Use three-point support, with each point carrying part of the weight. The decorative plate balance guide explains how useful proportions influence stability as well as appearance.

Distribute Weight, Space and Heat

Place the heaviest and largest forms low in the kiln, directly above strong supports. Build lighter and more fragile pieces above them, keeping tall work away from the walls where temperatures may vary. Do not concentrate delicate open forms in the centre if that leaves them exposed to uneven heat or condensation during cooling.

Small vessels still need room to heat. A tightly packed centre can develop different temperatures from the outer shelves and produce uneven glaze results. Alternate large and small pieces to create circulation paths, but do not create unstable gaps. Check that every shelf remains supported and that no piece projects beyond the kiln wall.

Use cones, heatwork indicators or an approved temperature controller as checks rather than assumptions. A satisfactory reading at the controller does not guarantee that every shelf has received the same heat. Place indicators near the top, bottom, centre and loaded edge to reveal differences before they appear in the finished glaze.

Account for Australian Conditions

Australian workshops commonly use 240-volt electricity, while high-capacity electric kilns may require a dedicated circuit or three-phase supply. Check the kiln manual and have the installation assessed by a qualified electrician. Adequate ventilation also matters, especially during busy firing seasons and in workshops affected by smoke or airborne dust from bushfires.

Local clay and inclusions deserve careful attention. Coastal deposits and beach sand can introduce iron, salt or organic material that causes pinholes, bloating or colour changes. Melbourne’s changeable weather, Sydney’s coastal damp and Brisbane’s humidity can all slow drying, while Adelaide’s hot, dry summers can make uneven drying more likely.

Document the finished arrangement with clear photographs and keep the load map with firing records. The Max Goh photography portfolio demonstrates how a considered image can preserve the position and surface detail of a complex collection for later reference.

Turn the Firing into Market-Ready Work

Allow the kiln to cool according to the manufacturer’s instructions before opening it. Glazed work can remain hazardous well below visible red heat, and early access increases the chance of thermal shock, chips and glaze sticking to shelves. Wear suitable gloves and eye protection, then unload from the most stable level downward.

Compare the finished pieces with the load map, photograph them and record any defects while the details are fresh. Works that sell through independent ceramics markets, design fairs and galleries in Melbourne, Sydney and Brisbane benefit from consistent images, accurate dimensions and reliable provenance.

A successful firing becomes more valuable when its lessons are carried forward. Explore the Amelia Creations workshop calendar for hands-on clay sessions and related events, including experiences with wine and tapas, and prepare your next complex load with a clear plan, stable supports and a well-kept firing record.