How to fix a crack in a stone mantel

Return the highlight of the room to its former glory.

A stone-manteled fireplace is often the highlight of the room. We like them so much that we turn our furniture towards them and gather around them whenever we can. Over time, cracks inevitably appear in most mantles, and taking care of them now can help keep yours the focal point of the room, as it should be. Whether caused by heat stress or a careless knock, quickly taking care of cracks that form can prevent them from growing and potentially avoid structural damage to the fireplace down the line.

Step 1: Prepare the plan, tools, and area

No good fireplace mantle repair happens without a good plan. You will have to consider what material you will use to fill the cracks, what applicators and tools you will need, and mark, clean, and dry the area. The two most common filler materials are:

● Caulking – Easiest, cheapest, and fastest option for hairline cracks. Caulk and caulking equipment are widely available and are available in all shades and finishes to match your mantle. Any hardware store should be able to help you find the right products.

● Epoxy / Epoxy with Stone Dust – Epoxy is a good choice for any crack wider than 1/8th of an inch, and the addition of stone dust can help you get that absolutely perfect match. Epoxy kits are also widely available in hardware stores, however, it might be a bit tougher to find the stone dust. If you are planning on using the epoxy and stone dust method, we strongly recommend that you buy an epoxy kit with a mixing set and applicator tip.

Once you’ve purchased the right filler and applicator tools for you, marked all the areas you wish to repair, cleaned the area of any dust, debris, or grime, and allowed it to thoroughly dry –move on to step 2.

Step 2: Apply the filler material

If you’re using caulk, press the nozzle into the edge of the crack and apply in a forward moving motion. This helps push the material deep into the crack, filling it completely. Wipe down any excess and allow to dry. This should solve the problem right there and then, and you can enjoy your fireplace once the caulk is dry.

If you’re using epoxy without stone filler, a good tip is to get a large-gauge needle and syringe from a pharmacy and use that to apply the epoxy. It will allow you to reach every inch of the crack and evenly apply the epoxy in the right amount. If you apply too much, simply wipe up the wet epoxy from the surrounding area, but don’t worry about smoothing it out. Simply let it dry for now.

If you’re filling the cracks with epoxy and stone dust, slowly add the stone dust when mixing the epoxy. Keep adding stone dust until it perfectly matches your fireplace mantle. then use the applicator tip to fill your marked cracks. Once again, wipe off any excess epoxy from the surrounding areas, but don’t attempt to smooth it out with the applicator. Let it dry.

Step 3: Sanding and finishing

Once the epoxy is dry, it’s time to sand down any rough edges and imperfections to get that perfectly smooth finish. It’s important to use fine-grit sandpaper, upwards of 1000 grit, to ensure you don’t scratch the stone and damage the finish. Stone polishing kits are available with the right grit for the right stone, although hand sanding is also a viable option. Wipe the repaired area down with a damp rag, and marvel at your handiwork.

When to leave it to the pros

Although fixing a crack in a stone mantle is a viable option in many cases, we strongly recommend contacting the pros for cracks larger than half an inch, or if the cracks are affecting the fireplace’s structural integrity. WeRestoreSurfaces has the know-how, tools, and experience to restore your fireplace mantle to perfect condition in no time.