What Do the Stains on Your Chimney Mean?

In a perfect world, chimney bricks would always be the beautiful color they began with. Over time, chimney masonry can become stained, discoloring the bricks and marring the overall appearance of the chimney. Cosmetics matter, but more importantly is why the stains are appearing. National Chimney Cleaners of Morris County, NJ, and Fairfield County, CT, would like to share some details on why chimneys become stained and how to resolve the problem. Here are 4 causes of common chimney stains.

Chimney Repair Jefferson, NJ

  1. Black chimney stains

This stain is caused by soot and is mostly seen with open masonry fireplaces. If you see varying degrees of black staining on your chimney masonry, the chimney probably needs to be swept (cleaned). This can reduce or eliminate the problem. Excess soot comes from excess smoke, which may be the result of burning damp wood rather than dry, seasoned wood. Damp wood creates much more smoke than dry wood.

  2. White chimney stains

White staining on chimneys is fairly common. What you’re seeing is called “efflorescence,” and it happens when moisture leeches out the naturally occurring salts within the bricks. A little white chimney discoloration is not an immediate cause for alarm. Significant white staining, however, can point to a serious breach to the chimney masonry and can lead to
major water damage throughout the system. If you have
a lot of white staining, schedule a chimney inspection.

  3. Dark green chimney stains

If the stains you see are truly green-based and not actually black or brown, the problem likely is algae growth. This happens when water is allowed to sit in sections of the chimney’s bricks. Algae is also often found on the chimney crown at the top of the chimney, if there’s no full-width chimney cap to protect it. An inspection should be performed to determine why excess moisture is present. It could be because of a chimney leak, which needs to be addressed.

  4. Red chimney stains

Red stains are likely from rust and are most often seen on prefab chimneys when their chimney chase covers are rusted. Standard masonry chimneys may also develop red, rusty stains if their metal chimney caps or top-mount dampers are besieged by rust. The average homeowner can usually figure out why rust is appearing on the chimney, but professional service is needed to resolve the problem and prevent it from happening in the future.

Chimney Inspection Morris County, NJAddressing all chimney staining and discoloration issues

Any type of brick discoloration on your chimney is a sign that you should be aware of because the stains you see may be caused by a much more serious issue that will not stop on its own. When caught early, these issues can be resolved and the chimney can be restored to a safe, functional state. The first step with chimney discoloration (and any other “unusual” chimney issues) is an inspection by a licensed chimney professional. These professionals understand all the causes of chimney staining and can recommend the right action to solve the problem. Most chimney inspectors are equipped to perform any repairs that are needed to get your chimney back into top shape.

Help for your chimney

National Chimney Cleaners is here to help with all your chimney needs, from inspection and repair to expert chimney sweeping and chimney rebuilding. If you live in the Morris County, NJ, or Fairfield County, CT, regions, give us a call at 800-631-6177. You can also reach out through our handy contact form.


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