Firebox Restoration

If you own your home long enough and actually make use of your fireplace on a regular basis, you will eventually have to have your firebox repaired or replaced; this could be the result of simple wear and tear or because of something more serious. Regardless of the cause, immediate action on your part is crucial, as using a fireplace without a sound firebox is extremely unsafe. Keep reading to learn what this job involves, why it’s so critical and how the professionals at Mason’s Chimney Service can help you throughout the entire process.

Inspecting Your Firebox

When a certified chimney sweep inspects your fireplace and chimney, the purpose is to identify and repair issues that can compromise the safety and functionality of the unit. If the bricks in your firebox are crumbling and/or the mortar joints are showing signs of deterioration, you have a fire hazard on your hands.

Refractory vs. Non-refractory Mortars

The extreme temperatures created by fires in your fireplace require special firebricks and high-temperature mortar be used in the construction of your firebox. The specific type of mortar used in fireboxes is called refractory mortar; however, the required use of refractory mortar in fireboxes is a recent addition to building codes. As such, the chances that refractory mortar was used in the firebox construction in an older home are slimmer than the same in a newer home.

The problem with the use of non-refractory mortar is that they don’t fare well in fireplaces that are used regularly. The problem is fairly straightforward: non-refractory mortar is Portland cement based, and Portland cement doesn’t hold up well when subjected to the cycle of heating and cooling that occurs in a firebox. Over the long haul, refractory mortar performs far better than Portland-cement mortar and is more readily available than it was a few decades ago.

Firebox Restoration 101

In order to repair damaged firebox mortar, you can take one of three approaches. The first approach involves simply scraping out and repointing the joints between the bricks with refractory mortar. The second approach involves applying a thin coat of refractory cement over the floor of the firebox. The final approach involves removing damaged bricks and replacing them with castable refractory cement. No matter which approach is taken, scrubbing the surface clean and vacuuming any dust before making the repair is critical.

When one of our CSIA-certified technicians is inspecting your chimney system, rest assured that we will pay close attention to your firebox to make sure no damage (i.e., cracks, mortar joint erosion, etc.) has occurred. If we do, however, find problem areas that need to be addressed, we will thoroughly cover all of the work details with you to ensure that you make the best, most informed decision possible. If you notice firebox damage on your own, contact us immediately and cease all usage of your fireplace until the issue has been repaired. You don’t want to put something like that off until it’s too late.