How to Fix a Veneer Stone That Has Fallen off the Wall

Clean the veneer stone thoroughly by rinsing it with a strong spray from a garden hose.

Put on gloves and mix the S-type mortar as recommended by the manufacturer. In general, the mortar should have the consistency of peanut butter when mixed properly. Make peaks in the mortar with the trowel or mixing paddle. The peaks should stay up without slumping.

Brush any dirt or debris out of the void from which the stone fell, using a stiff brush.

Apply 1/2 an inch to 3/4 of an inch of mortar to the back of the stone, ensuring that the entire surface is covered with mortar.

Push the veneer stone into the void, wiggling it in a little as you reset it. Use the tip of the trowel to remove any mortar that squeezes out onto the veneer.

Mix the grout according to manufacturer's directions. Fill the grout bag about 1/3 full, shaking the bag to settle the grout into the bottom of the bag.

Twist the top of the grout bag and then apply grout around the reset veneer stone. Push the grout well into the void surrounding the stone, then smooth and shape it with the tip of the trowel. Clean the veneer surface of excess grout, using a damp sponge.

Allow the mortar to dry for the time recommended by the manufacturer. Mortar usually dries in 24 to 72 hours, depending on the outside temperature and humidity.