Chimney and Firebox Rebuild

When a professional chimney sweep recommends that your chimney needs to be rebuilt, it is vulnerable to a chimney fire and beyond a simple repair of its existing materials. If the structural integrity of your chimney is no longer sound, such as this one pictured above, your professional sweep will recommend a rebuild.

There are four major causes that lead to the chimney’s end of life and these include its original construction, frequency of usage, maintenance and the weather. If there is faulty initial construction, frequent usage over many years, or a lack of annual maintenance and cleanings, your chimney will start to degrade. This usually means the mortar is crumbling or bricks are cracking or both. Your chimney is the only part of the rooftop that is not protected by the roof. The brick is exposed to all types of weather in your area. Exposure to the elements such as an infiltration of water or an area that freezes and thaws often throughout the year will cause wear on your chimney.  If it degrades the mortar completely, it will require a chimney rebuild.

Rebuilding a Firebox

If your fireplace has cracks or crumbling mortar when you run a trowel along the bricks, it needs to be replaced. If it is pre-fabricated, it is always necessary to adhere to the manufacturer’s pre-designated panels for the replacement of your firebox. If not, here are some steps that your professional chimney sweep will use to replace the firebox.

1)Masonry cement preparation: Follow the instructions that come with the cement package, and mix the appropriate combinations of sand, cement and other ingredients. Your sweep will want to have the existing mortar analyzed and matched so that the consistency of the new mortar matches the original.

2)Cleaning up the old stuff: Remove the mortar in the fire box using a hand rake and throw away this material. Mortar that is stuck to the bricks has to be loosened with the help of a crowbar and then released using the trowel. Only if the mortar is very stubbornly attached, is it a good idea to remove it with hard blows from a hammer. Once the mortar is removed, do not remove all bricks at once. First, take out the bricks at one section and replace them with the new set, one by one. Then, gradually move on to other sections and completely replace all the old bricks with new ones, also sealing them together using fresh mortar.

3) Combustible clearance: Your professional mason/sweep will make sure that the proper clearances to combustibles are done correctly for your type of firebox.

4) Brick pattern drawing: Use a trowel to draw the required patterns on the bricks. Apply cement with the refractories, on the panels, to give appropriate outlines.

If your fireplace is pre-fabricated, then your sweep will look at the bottom panel of your firebox for manufacturer’s specifications. They will remove it from the panel and order the new model according to the old model’s specifications.