How To Install Faux Stone Over Brick Fireplace Walls

Upgrading a brick fireplace with faux stone veneer offers a cost-effective way to modernize and enhance a room's aesthetic. This detailed guide outlines the process of installing faux stone over existing brick, providing a step-by-step approach for a successful DIY project.

1. Preparing the Brick Surface

Proper surface preparation is crucial for ensuring the long-term adhesion of the faux stone. Begin by thoroughly cleaning the brick surface with a stiff brush and a solution of trisodium phosphate (TSP) and water. This removes dirt, grime, and soot, providing a clean substrate for the veneer. Rinse the surface with clean water and allow it to dry completely before proceeding. Efflorescence, a white crystalline deposit often found on brick, should be addressed with a specialized cleaner. Any loose or crumbling mortar should be repaired, and the brick surface should be smooth and even.

If the brick surface is particularly smooth or glossy, it's recommended to roughen it up slightly to improve adhesion. This can be achieved using a wire brush, grinder with a masonry wheel, or by applying a concrete bonding adhesive. A bonding agent creates a textured surface, which is especially important for smooth, painted brick.

2. Gathering Necessary Materials and Tools

Having the right tools and materials readily available streamlines the installation process. The essential items include: safety glasses, dust mask, work gloves, measuring tape, level, pencil, utility knife, tin snips (for metal lath if required), notched trowel, pointing trowel, grout bag, sponge, bucket, mixing container, drill with mixing paddle (for mortar), hammer, safety glasses, hearing protection, masonry chisel, and a wet saw equipped with a diamond blade specifically designed for cutting stone. The project will also require faux stone panels, mortar mix, grout, concrete backer board (if necessary), and corrosion-resistant screws (if using backer board).

Selecting the appropriate type of mortar is vital. A pre-mixed type N mortar specifically designed for veneer installation is generally recommended for its ease of use and reliable performance. Grout color should be chosen to complement the chosen faux stone. Finally, ensure sufficient quantities of both mortar and grout are acquired before starting the project based on the fireplace's dimensions and the faux stone coverage.

3. Applying the Mortar and Setting the Stone

With the brick surface prepared, the next step is to apply a scratch coat of mortar directly to the brick using the notched trowel. The notches in the trowel create channels, promoting a strong bond between the brick and the faux stone. Depending on the condition of the brick and the type of faux stone being used, a layer of metal lath or concrete backer board may be necessary to provide additional support and prevent the mortar from cracking. If using either, secure it to the brick surface using corrosion-resistant screws before applying the mortar.

Begin setting the faux stone panels from the bottom corner, working upwards and outwards. Apply a generous dollop of mortar to the back of each panel using the pointing trowel, pressing it firmly against the mortared surface. Ensure proper alignment and spacing between the panels, using spacers if desired for consistent joints. Stagger the joints to achieve a natural, stacked stone appearance. Use a level frequently to ensure the panels are straight and plumb.

Cut the faux stone panels as needed using the wet saw equipped with a diamond blade. Measure and mark the panels carefully before cutting to minimize waste and ensure accurate fits, particularly around corners and edges. Dry fit the panels before applying mortar to confirm the fit and make any necessary adjustments.

4. Grouting and Finishing

Once the mortar has cured for the manufacturer-recommended time (typically 24-48 hours), the next step is to apply the grout. Mix the grout according to the manufacturer’s instructions. Fill a grout bag with the mixed grout and apply it to the joints between the faux stone panels, pressing it firmly into the gaps. Remove any excess grout with a damp sponge, being careful not to smear the grout across the face of the stone.

After the grout has partially cured (approximately 30 minutes), use a pointing trowel or a grout tool to smooth and shape the grout lines, achieving the desired finished look. Finally, clean the installed stone with a damp sponge, removing any remaining grout residue to reveal the finished fireplace facade. Allow the grout to cure completely, usually 24-72 hours, before using the fireplace.