Take a screwdriver and scrape some of the mortar joints of your fireplace. If it crumbles out easily, you have a problem. When damage is found in the fireplace, you can be certain the chimney crown coupled with the extreme heat the fireplace endures is causing the problem.
This is what happens: Water gets in the cracks on the crown or through an uncapped chimney and filters down to the smoke shelf just above the damper. There the water mixes with the ash and soot that has accumulated to make lye which attacks the mortar holding the bricks together. This can literally make the fireplace fall apart because nothing is left to hold the bricks together. Repairs to the firebox should not be done with ordinary cement because it will not stand up to the high heat encountered. We solve the problem by carefully raking out the loose mortar to prepare the firebox to receive a new high-solids cement made to withstand the extremes of fireplace heat. This ensures a safe firebox for your fires. While it is a fix it is only a repair and unless yours requires a total rebuilding it will need to be redone from time to time. The problem comes not from the new material but getting the old and the new to bond to each other properly. Not all fireplaces can be repaired…some must be totally rebuilt in order to work properly.
No matter whether yours is a masonry fireplace or a prefab fireplace we suggest you get one of our heat shields to protect the masonry work even further. If done this way you will have a long-lasting repair.
Unlike in standard fireplaces, where the firebrick is four inches thick, the refractory panels in prefabricated fireplaces are only 1/2 to one inch thick. Those can not be patched as a standard firebox can. The base is so thin the patch fails often after being heated only once.
Using a high-heat refractory cement, we pour our own panels, reinforcing them with metal to give them a strong and durable life. Using the proper material and knowing how properly to do the repair is essential to a long-lasting repair.
Behind the firebrick panels is an air chamber composed of two pieces of thin sheet meta spaced about 3-4 inches apart. Convection moves air through the chamber when the fire is burning. The air comes in the vents at the bottom and exits through the upper vents. This movement keeps the back wall relatively cool. These units are also called zero clearance fireplaces because they can be placed next to combustible materials such as framing studs. So the integrity of the wall is of utmost importance.
You can get a factory replacement panel if you hunt far enough but you will only have what failed in the first place. Factory replacements are usually made of fire clay or light-weight vermiculite which are not as durable as our long-lasting custom poured refractory panels. We pour them to be an exact fit and reinforce them with a metal mesh and our customers get years of use from them.
Here is an example of a dangerous prefab fireplace in need of repair (left), and a panel we have poured to repair a firebox (right).
The firebrick is protecting the thin sheet metal wall of the fireplace. If not taken care of, the fires built-in it can eventually burn through the metal and reach the wooden framing members. You can imagine the result if that were to happen. In order to get the proper size and shape, we pour them ourselves using the proper materials for long-lasting protection.
This is a service we provide to our local service area only.
Once poured the panel must cure for at least 30 days before use. When first installed and the 30 day wait period is over we suggest having 2 or 3 small fires to promote the final cure of the panel.
Then we strongly suggest that you purchase one of our Heat Shields to offer greater protection and increase fireplace heat production by 30-40%.