As an alternative wall-covering company, we here at American Clay get a lot of questions spanning an assortment of topics. From how to apply American Clay in earthquake prone areas to how to keep your dog from licking it off the walls, it seems we’re getting close to having heard it all.However, some questions we get more than others. For those frequently asked questions, we have an
extensive section on our website providing detailed answers and explanations.
One of the most common application questions we get is in regards to fireplaces. “Can I use American Clay to cover a brick fireplace?” is one of American Clay’s most recurrent questions. So here is a detailed answer to that oh-so-common question.
“Can I use American Clay to cover a brick fireplace?”

The short and simple answer is YES! American Clay can definitely be applied over brick fireplaces!
The longer–but still simple–answer is, the brick substrate requires some proper preparation.
Categorized as a Substrate Category II, the brick surface needs a ‘brown coat’ of fibered cement, lime plaster, a site-based earth plaster or drywall.
A cement brown coat is usually the way to cover brick; it fills the mortar joints and flattens the whole area. “Brown” means that it is left with a sandy surface, rather like very rough sandpaper. The cement is left to cure, an absolute minimum of one week and preferably four weeks. Then the clay plaster can be applied directly to the cement brown coat, which is now a Substrate Category III.
Keep in mind, it is best to follow the
manufacturers’ recommendations when using a leveling coat for bonding it
to the brick–or painted brick–substrate.
If you are using cement as your brown coat, sanded primer is not required. However sanded primer IS required if the surface has been leveled with gypsum, drywall, joint compound, Structo-Lite, or any other variation of gypsum.
Depending upon how much abuse you think your hearth will receive, we would suggest that you consider adding Mud Glue to both coats of plaster. The Mud Glue makes the plaster more resilient and durable, while not significantly reducing the repairability or breatheability. Mud Glue does make the plaster a bit fussier about how much water is used in the mixing and compression, and it limits the bucket life (time to leave the plaster wet in the bucket) to 3-5 days. For this reason, you might consider using someone who is experienced in American Clay plaster to do the application.
For more information about properly preparing a substrate and American Clay application, visit the Product Application page.