You are preparing your fireplace for the winter season so that you and your family can enjoy the warmth and coziness that a roaring fire brings to your home. A quick inspection of your fireplace and you notice that there is a crack in the brick of the inside lining. How does one repair those cracks in the firebricks?
Most of us know that repairs done on normal brickwork are usually done with mortar. Mortar is a mix used with water to make a paste that is used to build or repair brickwork. However, using mortar in a fireplace can lead to disaster. The water used to make the mortar paste can become steam and perhaps explode. Hot ashes and fire could be all over your floor and hearth.
Firebricks should be replaced when they are loose or damaged. Many times, you want to leave that to a professional. An oily substance and highly flammable byproduct of wood burning fireplaces is creosote. This byproduct can build up in the cracks of the firebricks. It can also travel past those cracks into the firebox and other parts of the chimney. Creosote is easily flammable and can ignite quickly. A chimney fire can spread fast into a house fire, giving you good reason to consult a professional on major chimney repairs.
However, if you need to simply patch a crack in the joints of the firebricks, use refractory fireclay cement. Most home repair or building supply stores will carry it. First with a stiff, small pointy tool like an old butter knife or pocketknife, remove any loose refractory fireclay around the bricks. Then use the knife to make a small groove where you are going to place the new fireclay cement. Using your knife, force the fireclay cement into the newly carved groove you have made. Let dry before using your fireplace.
Now that you have spent some time getting your firebox repaired, you should take a look at your flue liner. Make sure that it is free of debris and that there are no visible cracks. Check your damper and make sure that it works freely. Open and close it several times to make sure it is unobstructed. If you have a chimney cap, and for safety reasons you should, check to see that it is secured firmly and that the screening is in good condition.
Finally, while outside check for overhanging tree limbs. These tree limbs could possibly burn or restrict the air draft to your chimney. Keeping your fireplace and chimney clean and safe will enhance your family's enjoyment for years to come.