Behind every finished tile is a carefully controlled firing process. While firing might look like simply heating clay until it’s hard, each stage serves a specific purpose and plays a major role in the final look, durability, and consistency of our tile.
At Red Rock Tileworks, we use both gas and electric kilns, each chosen for what it does best. Here’s a closer look at how bisque firing and glaze firing work—and why both are essential to our process.
What Is Bisque Firing?
Bisque firing is the first firing in the ceramic process. At this stage, the clay tile is still fragile and porous. The goal of bisque firing is to transform raw clay into a hardened, stable material that’s strong enough to handle and ready to accept glaze.
We do our bisque firings in an updraft gas kiln. Gas firing is a cost effective firing process that creates an option for a fuel-rich environment, which introduces subtle variation and character while allowing us to carefully control the firing atmosphere.
During bisque firing:
- Physical and chemical water is driven out of the clay
- Organic materials burn off
- The tile becomes permanently hard but remains porous
That porosity is critical—it allows the glaze to absorb evenly during the next step.
Why Use a Gas Kiln for Bisque?
Gas kilns give us a more hands-on firing experience. Because they’re influenced by flame, airflow, and atmosphere, they require constant attention and adjustment. This variability isn’t a drawback—it’s a tool.
Using an updraft gas kiln for bisque firing allows us to:
- Gently and evenly harden the clay
- Maintain control during a sensitive stage of firing
- Set the foundation for how the glaze will behave later
Bisque firing is all about preparation. A well-fired bisque leads to better glaze results.
What Is Glaze Firing?
Once tiles are bisque fired, they’re glazed and ready for their final transformation. Glaze firing is what melts the glaze, fuses it to the clay surface, and brings color, texture, and depth to life.
We do all of our glaze firings in electric periodic kilns. Electric kilns offer a much more consistent firing environment, which is essential when repeatability and surface quality matter.
Why Electric Kilns for Glaze Firing?
Consistency is key when firing glazes. Electric kilns provide:
- Even heat distribution
- Precise temperature control
- Minimal variation from firing to firing in an oxidized environment
This allows us to achieve reliable, repeatable glaze results—especially important when producing tile for larger installations or matching previous batches.
Our Firing Cycle
Both our gas and electric kilns run on a 16-hour firing cycle:
- 8 hours to rise to peak temperature (cone 06)
- 8 hours to cool naturally
We fire low-fire, which is hot enough to fully melt the glaze and create vibrant surface color, but cool enough that we’re not wasting energy or fuel by over-firing. This temperature range is ideal for indoor tile applications, where durability, color clarity, and efficiency matter most.
Choosing the Right Kiln for the Right Job
Every kiln has a purpose. Our gas kilns give us control and character during the bisque stage, while our electric kilns provide consistency and precision during glaze firing. Together, they allow us to balance craftsmanship with reliability—resulting in tile that’s both beautiful and built to last.
If you’d like to see this process in action, check out our latest Tile Talk Tuesday video for a behind-the-scenes look at how our kilns work.