Some customers give us a call after their first few oven fires because they see cracks appearing on their brick wood-fired oven. First, just know that your authentic brick oven will show signs of cracking. However, it won't crack like the blog post cover if you go through the curing process properly.
Why Do Ovens Get Outside Dome Cracks?
When authentic ovens are built, moisture is trapped in the layers of brick, mortar, cement, or clay. When you cure your oven, you create small fires to allow the heat to slowly rise thus pushing the water out of the oven dome. As the heat rises, the moisture in the oven materials will turn to steam and attempt to escape the oven walls quickly.
It is best to make curing a slow process to minimize cracking but, due to the process, superficial cracks will still occur. While some traditional ovens may crack more than others, these superficial cracks create no structural damage and your oven will live for a long and prosperous life.
Here's the deal...
Larger cracking in your brick oven means the fires started in the oven were too hot over too fast a timeframe. Keeping your fires low and slow is the best policy during the curing process.
It is best to use your oven for a couple of months to allow it to crack where it will before you repair, paint, tile, or stucco. Just as you may patch and repaint cracks in your home over the years, your oven may require the same care and maintenance over time. But like all luxuries, it will be totally worth it!
What About Inside Oven Brick Cracks?
If the bricks inside your oven dome crack, it's not the end of the world. If your handmade oven is triple-insulated like our brick ovens from Authentic Pizza Ovens, your oven will continue to hold heat and cook perfectly. When building the Authentic Pizza Ovens brick wood-fired ovens, the craftsmen begin with a layer of brick and mortar, which is then covered with refractory cement. A thick layer of Rockwool insulation is applied and held down with metal batting before an additional layer of refractory cement is applied.
So, on the inside, there is so much mortar that cracks in the brick or mortar won't allow the heat won't escape. If your inside brick or mortar crack, you could lightly brush the inside to clean any loose mortar.
What If My Oven Face Cracks?
Creating blazing hot fires before properly curing your oven can result in cracks on your oven face. If your oven face cracks, you can use high-heat clear silicone to fill the crack. Remember that all cracks will expand when the oven is hot and then close up when the oven cools.
Covering your oven when not in use is the best practice. Since water can re-enter the oven walls or arch via rain, that moisture will again try to escape with subsequent firings potentially causing more cracking. For this reason, you should keep your oven covered when not in use or go through the curing process again if your oven was affected by rain or snow.
How To Repair Pizza Oven Cracks
If you're a perfectionist at heart, oven cracks may annoy you. But, as you will find, cracks in a traditional European oven dome simply means the oven has been used to its full potential. Cracks are the sign of a seasoned oven.
It may be best to make inner peace with oven cracks and assume that periodically minor repair will be necessary. If not, you may want to consider a steel wood-burning oven that will never crack.
If you just can't stand it and want to repair the brick pizza oven cracks, you can smooth over the cracks using similar material (ie, refractory cement, mortar, clay) or use the Ultrafire Repair Kit to fill the cracks.