The mortar in a fireplace can crumble over time due to the constant heating and cooling of the bricks when you build fires. Crumbling mortar and cracks in bricks make your fireplace look ugly. They can also pose a fire danger if the damage is in the right place and heat or fire escapes through the damaged area. Your fireplace should be inspected annually, as well as each time it is cleaned, so repairs can be made. Here's a look at how bricks and mortar in a fireplace are repaired.
Heat Resistant Materials Are Used
The mortar used in fireplace bricks is different from mortar used in brick walls, because a fireplace is subjected to such intense heat. The mortar is called refractory mortar. It's made from magnesium silicate rather than sand and cement. This type of mortar can withstand extreme temperatures. Likewise, the bricks used are called firebricks, and they're designed for contact with high heat.
Old Mortar Is Scraped Out
If the mortar is crumbling or if a brick is cracked, the first step is to scrape out the old mortar with a tool designed for the purpose. Once the mortar is out, the damaged brick can be pulled out and replaced. Digging out the mortar creates a lot of dust and this has to be cleaned up before new mortar can be put in. Also, if the damaged brick is in an area covered with soot, the soot needs to be washed off first. It isn't necessary to let the bricks dry out before repairs are made since they need to be wet during the process anyway and the contractor will probably spray them with water before applying the new mortar.
New Mortar Is Applied
A new brick of a similar color is slipped into the hole created by removing the old brick, and then new mortar can be applied. If the problem is just crumbling mortar and the bricks are fine, then the bricks can be left in place during the repairs. New mortar can be troweled into the cracks between bricks or put in with a caulk gun, then tamped down and leveled off.
Repairs can be done to single bricks, and if the fireplace has extensive wear and damage, a professional can repair large sections to make the fireplace usable again. Whether the bricks are inside, on the floor, or on the mantle, you should have repairs done when you notice cracks in bricks or crumbles in mortar because the damage might continue to get worse. While the mortar and bricks used to make fireplaces are intended to withstand high heat, eventually the heat exposure and frequent expansion and contraction take their toll on a fireplace, so occasional repairs are needed to ensure your fireplace has a long life and is safe to operate.
Contact a company, like Excel Chimney & Fireplace Service, for more help.