How to Repair a Damaged Stone Fireplace Surround

  • 3-6 hours
  • Intermediate
  • 50-200
What You'll Need
Drop cloth
Cold chisel
Wire brush
Cold water
Spray bottle
Replacement fireplace stones
Flat metal piece

A stone fireplace surround is appealing to most homeowners who want to have a natural and rustic appearance. After some time, the stone fireplace surround undergoes wear and tear of the mortar, due to thawing and freezing weather cycles which create shrinkages and cracks. Repairing the damage by re-pointing the mortar helps provide a cohesive stone appearance, and keeps the stone fireplace surround looking great. Repairing a damaged stone fireplace surround is not difficult. Simply follow the step-by-step instructions below.

Step 1 – Inspect and Mark Damaged Areas

Inspect the stone fireplace surround for chips, crumbling and cracked areas. Make a mark with a chalk on these areas, so that you don't have to search for them again later on.

Step 2 – Remove the Damaged Areas

Lay out a piece of drop cloth beneath the wall of the stone fireplace surround to catch the debris. Use a hammer and cold chisel to chisel the crumbling or damaged mortar out. Make sure that you get into all the cracked and damaged areas by chiseling into them at least ½-inch in depth.

Step 3 – Pry out the Damaged Stones

Use the blunt chisel side to pry out the damaged stones. Chisel out the mortar surrounding the damaged stones so that you can properly remove them. Don't hesitate to chisel the mortar out as needed, because you will be filling in all the mortar areas later on.

Step 4 – Scrub the Chiseled Area

Use a wire brush to scrub the chiseled area. Remove any debris and dust from your chiseling work. Scrubbing flattens the surface, and preps the wall for filling in new mortar.

Step 5 – Apply Mortar onto the Replacement Fireplace Stones

Mix water and mortar in a bucket. Follow the instructions on the mortar labels for mixing ratios. Spray a thin layer of water mist at the back of the replacement fireplace stone using a spray bottle. Use a trowel to spread a thin coat of mortar evenly across the back of the replacement stones.

Step 6 – Install the Replacement Fireplace Stones

Install the replacement fireplace stone by pressing it into the place where you removed the damaged stone in step 3. Wiggle the stone slightly to make sure there is proper coverage. Follow the same procedure for installing all the other replacement stones. Let the mortar dry overnight.

Step 7 – Fill the Joints with Mortar

Use a cloth and cold water to damp the joint areas you want to fill with mortar. Spread the mortar on the flat metal piece. Scrape it on the fireplace surround wall surface using a trowel. Use the flat trowel side to force mortar into the joints, ensuring that it fills the joints completely. Let the mortar set for at least 10 minutes. After the mortar has set, even and match the new mortared joints to other wall joints by running a jointer into the mortar.

Step 8 – Finishing

Use the flat side of the clean trowel to remove the excess mortar from the newly mortared joints. Let the mortar set for at least 30 minutes. Sweep the mortar with a wire brush for a worn-in look.

Step 9 – Moistening

Let the mortar cure gradually by moistening the newly mortared joints twice a day for the next four days. This way, the mortar will not dry too quickly and cause it to crack.