Masonry 101 | How To Deal With A Spalling Chimney

Masonry 101 | How To Deal With A Spalling Chimney

14 September 2022
 Categories: , Blog


If you're like most homeowners, you probably do not give much thought to your chimney until you start having problems with it. By then, however, it is often too late. A spalling chimney can be a serious safety hazard. Here's what you need to know.

What is a spalling chimney?

A spalling chimney is a chimney with masonry that is beginning to break down. The bricks or mortar start to flake off, and the structure itself starts to weaken. It may be missing chunks of concrete, full bricks, or even look dangerously close to toppling over and falling to the ground.

What causes spalling in chimneys?

Several things can cause spalling in a chimney, including:

  • Water infiltration. The most common cause of spalling is water infiltration. When water seeps into the bricks or mortar, it can cause the masonry to expand and contract. Over time, this can lead to cracking, flaking, and, eventually, spalling.
  • Chemical reactions. Certain chemicals can cause masonry to break down. For example, muriatic acid is often used to clean brick and stone surfaces. However, if it's not diluted properly, it can eat away at the masonry, causing it to flake and crumble.
  • Poor workmanship. If a chimney isn't built properly originally, it is more likely to experience problems down the road. This includes things like using the wrong mortar mix or not allowing the mortar to cure properly before use.

How do you fix a spalling chimney?

The best way to fix a spalling chimney is to have it professionally repaired by a masonry contractor. The masonry contractor will be able to assess the damage and make the necessary repairs, including tuckpointing, repointing, and rebuilding.

What is the difference between tuckpointing and repointing?

While tuckpointing and repointing have similar sounding names, they are masonry repairs that serve different purposes. Tuckpointing is a type of masonry repair that involves adding new mortar to the joints of a brick structure. Tuckpointing is usually done to improve the appearance of the brickwork. Repointing, on the other hand, involves completely removing the old mortar from the joints and replacing it with new mortar. This is usually done to improve the stability and strength of the brickwork.

If you have a spalling chimney, it's important to have it repaired as soon as possible. Otherwise, you could be putting your safety at risk. Contact a masonry contractor in your area to get started.