Basic Brickwork Maintenance and Repair - Kilns & Furnaces

Basic Brickwork Maintenance and Repair

Kilns endure extreme conditions during firings, causing wear on their firebricks over time. Here’s a guide to understanding and conducting basic maintenance on your kiln bricks, ensuring longevity and optimal performance:


Normal Wear and Tear

After initial firings, hairline cracks and discoloration may appear in the firebricks—this is entirely normal. Despite their fragile appearance, firebricks are resilient and can withstand temperatures exceeding 1,100°C.


Understanding Cracks

Due to the constant expansion and contraction of firebricks during firing, cracks may develop while the kiln is cold. These cracks function as natural expansion joints and typically close tightly during the firing process.


Ventilation and Contaminant Prevention

Avoid introducing contaminants like silica sand onto the firebrick bottom, as this can widen cracks. Ensure proper ventilation to reduce the impact of fumes on the bricks.


Preventive Maintenance

Regular vacuuming is a simple yet effective maintenance task. Prioritize vacuuming before glaze firings, especially in element grooves, the inner surface of the lid, and under kiln shelves.


Coating the Brick Floor

Apply three thin layers of kiln wash to the firebrick floor to prevent glaze and glass particles from embedding into the bricks. Ensure even application and avoid splashing onto sidewall elements.


Loading and Unloading Tips

Handle the kiln with care during loading and unloading. Avoid touching sidewalls, gently lower the lid, and distribute weight evenly. Extra precautions can extend the kiln’s lifespan.


Removing Contaminants

Promptly remove drips of glaze, glass, or other materials using a putty knife to prevent them from remelting and embedding deeper into the firebricks.


Repairing Minor Damage

Cosmetic damage, like minor lid cracks or gouges, often doesn’t require repair unless affecting firing results. Use caution when considering repairs, focusing on issues impacting kiln performance.


Coating and Repair Cement

For coating, use kiln wash or glass separator rated to 2400°F. Liquid Kiln Coating & Repair Cement is effective for repairing minor damages, ensuring a secure bond.


Patching Techniques

Practice patching firebrick scraps before attempting kiln repairs. For patches or inserts, ensure precise fits, and use Kaolin Grog mixed with repair cement for filling gouges.


Cementing Broken Pieces

Broken firebrick pieces can be cemented together if enough surface area is available for a strong bond. Follow proper cementing techniques to avoid issues during firing.


Cementing Flat Sections

Cement bricks along flat surfaces for a thin seam. Dip one surface into the cement, then slide mating surfaces together for an optimal bond. Allow the cement to set for 24 hours.


By following these basic maintenance guidelines, you contribute to the longevity and efficiency of your kiln. For expert brickwork maintenance or refurbishment, consider Kilns and Furnaces’ professional services. Your kiln’s performance and durability is our priority. Contact us at or visit for more information.

Refractory bricks stacked in Kilns and Furnaces' manufacturing facility.