Forth with whatsoever part of your home, your fireplace requires maintenance to ensure your family's condom during its utilise.  There are three chief components to your fireplace; the firebox itself (Modular, Masonry or Metal), the damper / chimney arrangement and the fire brick liner. Fire bricks absorb heat, providing a buffer between the fire and the firebox, maintaining a high temperature and preventing damage to the wall backside a fireplace.  Burn down brick mortar and/or fire bricks can go damaged subsequently years of employ which can cause a burn down brick to autumn out or fissure.  A cracked or damaged fire brick can be a potential fire gamble and should be repaired or replaced before using the fireplace over again.

Repairing Cracked Fire Brick

Supplies Needed:
Water
Detergent
Scourer
Fire Cement
Gloves
Trowel

Directions (for Individually practical Fire Brick):

1. Make clean any soot, grease or grit from the fire brick that is to exist repaired – let brick to dry out earlier get-go the repair.

2. Utilise burn down cement to the area that is existence repaired, using the trowel.  If the brick has broken into more than i piece, apply a layer of cement along one edge of the break and push the pieces firmly back together.  Wipe any excess cement from the brick.  If repairing a scissure, work the cement well into the area, removing any excess.

3. Apply estrus to the fire brick, gradually increasing the temperature over a 3 to four hour period.

4. Allow the brick to cool and check for farther cracks.  If additional cracks are found, echo steps one-3.

Replacing Damaged Burn brick

Supplies Needed:

Carbide-Tipped Scoring Tool meant for cutting tile backer board
Metal Jointer
Brick Trowel
Tuck-Pointing Trowel (narrow enough to fit in the brick joints)
Dry-Mix Refractory Mortar
Water
Paintbrush

Directions (for Individually practical Burn Brick):

1. Scrape out the loose mortar.  Rake out the articulation with the scoring tool – start gently, probing for areas that are loose.  Dig out the deteriorated mortar until the joint is near ½ to ¾ inches deep and the brick surface on both sides of the joint are mortar free.

ii. Castor the joint.  Use an old paintbrush and vacuum to sweep the joints clean.  Brush water onto the joints and brick faces (mortar doesn't stick to bone-dry out brick well).

3. Pack the mortar.  Mix a small batch of mortar co-ordinate the mortar directions and utilize to the brick in line with the articulation – pack into the articulation with a tuck-pointing trowel.  Pack about halfway full, then press firmly as you pull the pointing trowel (handle first) forth the joint until joint is filled.

four. Clean upwards by scraping the excess mortar off of the brick faces and so wipe immediately with a damp sponge.
Let the mortar dry completely for several days – later completely dry, rough up with a metal chisel if desired so it matches the surrounding mortar.

five. For factory built fireplaces with installed fire brick panels, contact the Fireplace Manufacturer for instructions on replacement/repair.

Note: Though each individual mason may have their own technique because of geographic conditions or grooming, these are some general procedures for repairing cracked fire brick.

Sources: ehow.com, This Old House