How to Repair a Broken Chimney Flue

What You'll Need

If you are living in an older house with an aging chimney flue, then you may find that you need to repair the flue before you start using it with a stove or a log fire. Repairing a flue is usually done by an expert, as toxic gases are produced during the heating process which can harm people in the living room. You cannot get the best results out of your heating system if you don't repair the damage on your chimney flue, and in fact you can prevent energy loss by repairing your chimney so taht it operates at its best. Getting this job done doesn’t need the assistance of a professional if you have some basic home improvement skills. All you have to do is follow a few simple guidelines to get the job done quickly and easily.

Step 1 – Clean the Chimney

The first step in repairing the chimney is to clean the chimney flue itself. This will help you to avoid being covered in soot and dust when you are moving the bricks, and also allow you to see the full extent of the damage. You should now examine the chimney, and assess whether you will be able to repair the chimney yourself, or whether you will need to call in a contractor to do the work. If there are serious flaws on the inside of the chimney, then you should definitely not repair it yourself, and you may need to consider taking down the structure, and replacing it with a good chimney.

Step 2 – Remove Damaged Bricks

You will only be able to remove the damaged bricks from the outside of the chimney, rather than anything in the inside, so using a hammer and chisel, knock out and damaged bricks, and place them to the side. You should keep any bricks that you can, possibly even dividing the bricks so that the damaged half can be thrown away.

Step 3 –  Replace the Bricks

Once that is completed, you will have to replace the bricks with some new ones. Try and find bricks that match the color of your original chimney as closely as possible. Using a layer of mortar, position the bricks as tightly together as you can, remembering that gases should not be able to escape through any gaps. Once you have completed the brickwork, you should cover all of the area with a layer of waterproof caulking, which will keep the chimney from any water damage, and also prevent heat and gas from escaping through gaps in the side.

Step 4 – Finishing

Before you finish the project you will have to check the rest of the brickwork to ensure that there is no more damaged mortar in the surrounding area. Old mortar might chip and crumble, so look out for mortar which crumbles under pressure from your fingers. You can apply a layer of caulk over the surface of the mortar in order to prevent any more mortar from crumbling away.