How to Repair a Chimney Crown


If your chimney is old and hasn’t been maintained for a long time, it may be starting to show its age. Pieces of it might be flaking off or cracks might be becoming wider and wider over time. If your chimney has deteriorated to this point, it is quite likely that you have already had to face some problems with the chimney crown.

The chimney crown is the part of the chimney that covers the top and manages the outflow of smoke. It is the most significant part of the chimney. If the chimney crown is not functioning right due to wear and tear, your chimney will continue to exhibit serious problems until the crown is fixed.

Problems that begin with the crown can affect the entire chimney. If the crown is not fixed in time, the very structure of the chimney will become at risk. The usual causes of problems with the chimney crown are torrential rains, extreme weather and very high or low temperatures which cause the crown to crack and split.

If your chimney is exhibiting these kinds of problems and the chimney crown is in bad shape, you need to deal with the crown first before you can repair the rest of the chimney. To get an idea of how to fix the chimney crown, here are some helpful instructions.

If there is no significant damage that you can see, get some thin and grainy mortar and apply it to all the tiny cracks that you can find. Be careful that the mortar mixture you make is syrupy and not too thick.

#1. Fill up the cracks

Filling up the visible cracks in this way is a stop gap solution and will resolve the chimney issues for a while. However, this is not a long term solution. The problem with this measure is that the next time it rains or gets too windy, the mortar that you filled up will probably flake off and the cracks will be exposed again.

#2. Caulk the cracks

This is a better solution than simply filling up the cracks with mortar. Examine all the visible cracks and clean them of any debris, rocks and dirt that has accumulated on them. Once the cracks are clear, fill them up with caulk.

#3. Remove the crown

If the measures mentioned above have not worked for long, you will need to remove the damaged crown. Use a hammer and chisel and delicately break off the concrete connecting the crown to the rest of the chimney. Once the crown has been removed, cover the top of the chimney with plastic sheeting to keep the rest of the chimney clean.

#4. Prepare fresh mortar

Mix cement and gravel with a little bit of water to create a mortar mixture that is good enough to repair the damaged sections of the base of the crown that you just removed.

#5. Apply the mortar

Once you have prepared fresh mortar to fix the base area of the crown, it is time to apply it. Examine the areas from which you removed the crown and fill up any visible cracks with the mortar. Carefully spread the mortar evenly across the uneven and broken areas and try to end up with a flat and smooth surface for the crown to rest on. Use a trowel to even out the base area.

Now place the chimney crown onto this flat surface and let the mortar dry. After it dries out, your chimney and the chimney crown should be as good as new and you shouldn’t have any problems for a long time.

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