Fire bricks are typical in pizza ovens and outdoor ovens because they withstand temperatures up to 3,000 degrees. However, you also can use fire bricks for interior flooring, and they add a distinctive look to any room. When used in your bathroom, they can create a rustic appearance reminiscent of an outdoor patio for a secret-garden vibe.
Remove the Old Flooring
You should remove the old flooring in your bathroom before you lay down the fire brick. While you may be able to get away with laying the brick on top of linoleum, it is preferable to have a clean surface on which to install your new floor. After you take out the old floor, make sure the subfloor is clean and level. Sand out any old grout or glue and flatten any raised nails. If the subfloor is weak or uneven, you can install a plywood underlayment to support your new floor.
Decide on Sheets or Bricks
There are two choices for fire brick flooring: Individual bricks or paneled sheets, sometimes called pavers. Individual bricks are typically thicker than the sheets and may create a raised floor that forms awkward gaps around your toilet and your tub. Paneled sheets are not only thinner, but they also cover more surface area at a time, making installation go more smoothly and quickly. Compare costs and available styles for each to decide which would best suit your budget and the plans you have for the design of your bathroom.
Lay the New Floor
Prepare to lay your floor by misting the subfloor and the bricks with a spray bottle of water. This will help them adhere to the grout. Add grout to the bottom of the bricks or paneled sheets and to the sides and begin placing them starting in a corner of the room. Use plastic spacers to help you maintain even spacing for the grout lines. Wipe away the excess grout after 10 minutes.
Work in rows across the room until you have filled the space, minus the gaps that would not accommodate full-sized bricks or sheets. Use a circular saw with a masonry blade to cut the bricks or sheets to size. Install the custom-cut pieces to complete the floor.
Finish the Job
Tap the fire bricks into the grout with a rubber mallet to ensure a good bond and an even setting. Wipe up any excess grout. Leave the grout to set for at least 48 hours. Apply a sealant to the grout once it has cured to protect it from cracks and stains. Alternatively, you can choose a sealant that covers both the brick and the grout, which will give the whole floor a shiny, smooth finish and protect it from damage. The sealant will have to be reapplied every few years to continue to protect the floor.