Using a trowel, apply fire cement to the damaged area. If the brick has broken in more than one spot, put a layer of cement along the edge of each break and firmly push the pieces back together. Clean off any excess cement. If you are repairing a crack, push the cement into the crack and remove the excess.Click to see full answer. Then, can you repair fire bricks?Fire brick mortar and/or fire bricks can become damaged after years of use which can cause a fire brick to fall out or crack. A cracked or damaged fire brick can be a potential fire hazard and should be repaired or replaced before using the fireplace again.Subsequently, question is, how do you replace fire bricks in a fireplace? How to Replace Fire Bricks in a Wood Stove Open the wood stove door and remove any debris. Clean ashes out of the stove and remove the log grate. Pull any damaged fire bricks from the stove with your fingers. Clean the empty area, thoroughly removing all debris. Place the new fire brick into the empty space and push it into place. Subsequently, question is, how do you fix loose bricks in a fireplace? Clean the joints around loose bricks. Mix up some mortar in a bucket with your margin trowel. Apply mortar to the bottom side of the area where you need to reinstall your bricks. Place the brick(s) in place on top of the layer of mortar. Scoop some grout into the grout bag. How do you fix a fireplace insert? Fireplace Insert Fix Step 1: This Is Unsafe! Check out your fireplace. Step 2: Tools Needed. All you need is: Step 3: Cleaning. Clean the inside of the walls with soap and water and a big sponge. Step 4: Add Caulk. Slightly dampen the crack you need to fill, one at a time. Step 5: Smooth Caulk. Step 6: Repeat. Step 7: Dry Time. Step 8: Curing.