Helpful Tips

Cracked Chimney Mortar – How to Fix It


A chimney is a real cornerstone of any home. It’s essential for letting out smoke and heating the house. Unfortunately, with the passage of time, joints between stones or bricks can fade, wash out or crack. What causes this damage and how to repair mortar cracks in chimneys?

How to maintain the chimney

Regular chimney maintenance is the key to preventing damage and costly repairs. At least once a year, you should have your chimney inspected by a professional. They’ll be able to identify any potential problems and make recommendations for repairs or maintenance. In addition, you should be sure to sweep your chimney on a regular basis to remove any buildup of debris and keep it safe.

But what to do if you suspect that your chimney requires repair?

How to recognize cracked chimney mortar

The easiest way to recognize cracked chimney mortar is to look at the outside of your chimney. If you see any cracks or missing mortar, it’s a good sign that the mortar needs to be replaced. You can also take a look at the firebox. If the mortar is cracked there, it’s likely that the chimney is in need of repair.

What causes chimney damage?

There are many things that can cause cracks in chimney mortar. Some common causes of the damage include:

  • Water – it’s one of the most common causes of chimney damage. It can enter the chimney through cracks or leaks and can cause the chimney to deteriorate over time.
  • Animals – birds, squirrels, and raccoons are just a few of the animals that can enter a chimney and nest there. They can cause damage to the chimney with their nesting materials, and can also cause blockages that can lead to dangerous situations.
  • Weather – it’s another important factor that can contribute to damaging a chimney. Extreme temperatures can cause the chimney to crack, and high winds can even lead to a collapse.

Repairing cracks in chimney mortar – how to do it

How to repair mortar cracks in a chimney? If you’ve noticed cracks in your chimney, it’s important to repair them as soon as possible to prevent further damage.

First, you’ll need to clean out the cracks to remove any loose mortar or debris. Next, you should get the repaired mortar and mix it according to the instructions. Once it’s ready, you’ll need to apply it to the cracks, using a putty knife or trowel. Be sure to smooth it out so that it’s level with the rest of the mortar.

Once the repair mortar is dry, you’ll need to apply a sealant to protect it from the elements. You can find it at most hardware stores. Just be sure to follow the instructions on the packaging.

Not sure if repairing cracks in chimney crown mortar is for you? Contact specialists working at N&M Restoration. We’ll be happy to help you.

The takeaway

Repairing cracks in chimney crown mortar can be a time and energy-consuming task that requires certain knowledge and expertise. 

If you aren’t sure how to proceed, or what materials to use, benefit from professional services that will help you renovate your chimney and keep it in good condition for longer.