How to Install Fieldstone onto Brick

Remove dirt and other debris from the brick surface with a medium-size sponge wet with warm water or, if the brick is outdoors, with water from a garden hose. Allow the brick surface to dry thoroughly.

Blend mortar in a large bucket according to its manufacturer’s instructions. Scoop the blended mortar with a mason’s trowel, and apply it on the brick in an even 1/2-inch thick layer. Use a mason's scratcher to make even, horizontal lines in the mortar, creating a rough surface. Allow the mortar to dry for 48 hours. The result is a sturdy surface, known as a scratch coat, to which fieldstones can adhere.

Mix a new batch of mortar per the manufacturer’s instructions. Smooth about a 1/4-inch coat of the mortar onto the entire back of one fieldstone with the mason's trowel. Press the fieldstone onto a bottom corner of the brick surface. Wiggle the fieldstone on the brick surface slightly to ensure the mortar presses into the scratch coat. Repeat this process with the remaining fieldstones, placing them in rows from bottom to top on the brick surface and keeping the fieldstones about 1/4 to 1/2 inch apart.

Dampen a medium-size sponge with hot water, and use it to wipe the surface of each fieldstone clean, removing exposed mortar. Allow the remaining mortar to dry for 72 hours.

Blend grout according to its manufacturer’s instructions. Fill three-quarters of a grout bag with the blended grout by scooping the grout with the trowel. Grasp the grout bag's top with one hand, and support the bag with your other hand. Position the bag's top, or tip, in the seam between two fieldstones on the brick surface, and squeeze the grout bag to expel grout. Move the bag slowly along the seam, applying an even layer of grout into the seam. Continue this process until all the seams between the fieldstones are filled with grout.

Wipe grout from the outer surface of the fieldstones with a warm, damp sponge. Allow the remaining grout to dry for 48 hours.