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What’s Growing in Your Chimney?

Inside Your Chimney: Algae and Plant Growth in High-Moisture Areas

Do you spy algae growing on your roof or chimney masonry? This is more serious than the cosmetic concern it may appear to be. For starters, algae, moss, lichen, or mold on your chimney signifies the presence of moisture in and on your chimney, which is one place where water should never be.

Water can create all sorts of problems for your chimney - A major one is algae growth. Make sure to waterproof your chimney.

Water can create all sorts of problems for your chimney – A major one is algae growth. Make sure to waterproof your chimney.

In addition, there are some varieties of algae—one in particular known as “gloeocapsa magma”—that can literally eat away at roof shingles, limestone, and mortar, degrading your chimney’s integrity. And moss and lichen, which can take root on your roof and chimney, are thick enough so that when they freeze they will hold water against your roof for long periods of time. At Pristine Chimney Sweeps we can clean the algae and any other plantlife off your chimney and waterproof it to protect it from the formation of any more damaging green stuff.

What Is Algae?

Algae is a plant or plant-like organism of any of several phyla, divisions, or classes of chiefly aquatic origin. Algae can be green, yellow-green, brown, or red. Algae, moss, and lichen thrive in moist, shady environments—hello, Seattle! After all, this is a plant that grows under water. So what’s this aquatic plant doing on your roof or chimney? Probably thriving—all while destroying your roof and chimney.

Why Algae Has No Place On Your Chimney

Besides the fact that algae leaves unsightly stains on your chimney, the presence of algae indicates that water has intruded into your chimney’s brick and mortar, after which point it can get inside your chimney and inside your home, where it can wreak havoc on your ceilings, walls, and floors. Water damage to a chimney also manifests itself in the form of rusty chimney components, compromised liners, and crumbling masonry.

How We Remove Algae from Chimneys

All of our consultations with clients start with a thorough video inspection of the chimney. Before we treat a sick chimney, we have to look at it completely to determine the most efficient and cost effective way to make it well again.

When it comes to algae removal, in addition to power-washing your chimney, the CSIA certified technicians at Pristine Sweeps will seal up all cracks and gaps in your chimney and finally apply a water repellant specially designed to keep water out of your chimney for the long haul.

Have questions about algae on your chimney or chimney waterproofing? Contact us today.

Checklist for Your Chimney this Spring

Spring is the best time to do some fireplace and chimney care. Make it a priority on your spring checklist.

Spring is the best time to do some fireplace and chimney care. Make it a priority on your spring checklist.

After a long, cold, rainy winter, you’re ready for spring, and you know it’s time for spring cleaning, and that includes your fireplace and chimney. Living in the Pacific Northwest, we get lots and lots of rain, even during the fall and winter, and this means possible water leaks, a major source of headaches when it comes to chimney repairs. So, spring chimney cleaning can entail a lot of tasks, but Pristine Sweeps compiled a simple checklist for your chimney that can be easily accomplished.


Causing possibly hundreds to thousands of dollars in chimney damage repair, water leaks are a chimney’s worst enemy. Although generally by the flashing, they can be hard to locate, so call us at Pristine Sweeps to schedule a professional leak inspection. However, there are signs of water leaks that you should always be keeping an eye out for:

  • patchy, white spots
  • plants growing in cracks in the mortar
  • cracking and crumbling in the bricks and/or mortar
  • rusty stains
  • brick discoloration
  • water in the fireplace
  • damp odors


According to the Chimney Safety Institute of America, the efficiency of these two parts of your chimney is crucial to saving energy and money, as well as keeping water leaks out, over the spring and summer months. If your damper is stuck open, it is the same thing as leaving a window in your house open; cold air escapes, bugs get in, the rain pours into your house, etc. If the damper is stuck closed, you cannot start a fire because your flue is closed-off and unable to filter smoke and gases. Similarly, your chimney cap fitting correctly on the top of your chimney is very important because not only does it also keep rain out of your chimney, but it prevents stray animals from setting up home there.


These classic chimneys are a bit more elaborate and require different types of maintenance, but Pristine Sweeps specializes in masonry chimneys and is ready to help you check these jobs off your checklist:

  1. crown repair – Your crown is the chimney cap of your masonry chimney.
  2. repointing/tuckpointing/spalling – When the bricks and mortar of your chimney are crumbling and falling apart due to deteriorating joints from water damage, we can repair (or rebuild, if necessary) your chimney using these techniques.
  3. firebox repair – An essential role in the safety of your fireplace and chimney, your firebox should never be cracked or rusted. It needs to be in good working condition so that it can contain all of the heat safely.
  4. smoke chamber restoration – Connecting the throat of your chimney to the flue, a properly working smoke chamber ushers out smoke from your home. If there are any problems with the construction of your smoke chamber, you can have issues with toxic smoke fumes entering your home.
  5. throat repair – Just like the smoke chamber, the throat is important as it works to get smoke out of your house, and because it sits right above your firebox, the high temperatures can cause cracking and other damage, allowing smoke to escape into your home.


The spring is an excellent time to make your appointment for your annual professional chimney cleaning and inspection, and this step could be the only task you have to make this season. At Pristine Sweeps, our chimney sweeps include a Level 1 inspection with a video scan that allows us to spot things that are not visible to the naked eye, giving us the best view possible of the inside of your chimney. During our chimney sweep, we will be able to inspect all of the tasks on this checklist, so be proactive with your spring chimney checklist and contact us for an appointment today for your annual chimney sweep and inspection.