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Diagnosing Chimney Leaks

Water in your fireplace and chimney – whether it is a few small drops or a large puddle – is never a good thing. And because chimneys have many different components, identifying the exact cause of a chimney leak can be difficult. However, it is important to identify – and repair – the underlying cause of the chimney leak in order to prevent further water damage from occurring.

Diagnosing Chimney Leaks - Seattle WA - Pristine SweepsCommon causes of chimney leaks

The following are four of the most common causes of chimney leaks. Because every chimney system – and leak – is unique, a professional chimney inspection is often needed to identify the exact cause of the leaky chimney.

  • Chimney cap: Made of a solid metal top with mesh or wire sides, the chimney cap is designed to keep water, animals, and debris out of the flue. If the chimney cap is ill-fitting, incorrectly installed, or damaged in any way, water can begin to leak into the chimney.
  • Chimney crown: While chimney caps protect the top of the flue, chimney crowns seal the top of the chimney. Made of masonry, stone, or concrete, chimney crowns often bear the brunt of the exposure to the elements; their flat top means they are especially prone to water damage from rain, ice, and snow. Because of this, chimney crowns can crack and allow water in, causing a chimney leak.
  • Flashing: Flashing seals the joint between the roof and your chimney. Made by layering strips of metal to create a watertight seal, leaks caused by faulty flashing are often blamed on roofs instead. Whether it was installed with too many nail holes, was jostled while the roof was being repaired, or has simply been exposed to the elements for too long, leaky flashing can damage the roof, masonry, ceilings, and walls surrounding the chimney.
  • Masonry: Your bricks and mortar themselves can let water in. Because masonry is naturally porous, small amounts of water and constantly being absorbed. However, the absorption of too much water can damage the masonry; this leads to masonry holes and cracks that can create leaks.

Preventing chimney leaks

Oftentimes the best way to prevent chimney leaks is through regular chimney maintenance. Annual chimney sweepings and inspections can insure that no parts of your chimney are damaged – and that there are no unseen areas of water entry.

In addition to annual inspections, waterproofing may be able to protect your masonry against water. During the waterproofing process, specially designed masonry water repellants are applied to the bricks and mortar. These products penetrate deeply into the masonry, keeping new water out but allowing old water to evaporate.

Don’t let a leaky chimney cause damage to your fireplace and chimney system. Instead, have a chimney professional diagnose – and repair – the cause of your chimney leak. Contact Pristine Sweeps today for more information on how we can repair your leaky chimney and the damage to your fireplace it may have caused.

By Aaron Woodward | Tagged with: Tags: , , | Leave a Comment

Anatomy Of A Chimney

Your chimney is more than just a stack of bricks and mortar; in fact, chimneys are surprisingly complex structures  with different parts and components that all work together to keep your fireplace burning safely and efficiently. By better understanding the anatomy of your chimney, you can begin to learn more about the purpose and function of the unique – and important – components of your chimney.

Anatomy of a Chimney - Seattle WA - Pristine Sweeps

Chimney cap

The chimney cap is a metal cover used to protect the top of the flue; chimney caps also often have mesh or wire sides as a way to keep animals and debris from getting into the flue. In addition to keeping out moisture, animals, and debris, chimney caps can also aid drafting by preventing downdrafts caused by wind.

Chimney crown

The chimney crown is the masonry or concrete slab that covers the top of the chimney; the chimney crown seals around the top of the flue pipe which the chimney cap then sits on top of. Well-designed chimney crowns will have an overhang of at least 2-2.5 inches to allow water to flow onto the roof instead of the sides of the chimney. Because they often take the most “direct hits” from the elements, chimney crowns are more prone to damage such as cracking.

Chimney chase

While the flues of masonry chimneys are surrounded by bricks and mortar, the flues of prefabricated or factory built chimneys are surrounded by the chase. The chimney chase is built around the flue to protect it as well as help make it more aesthetically pleasing; chimney chases are often made using the same siding or building materials as the rest of the home.

Chimney chase cover

If you have a prefabricated or factory built fireplace, your chimney will have a chase cover in place of a chimney crown. The chimney chase cover is a piece of metal – often a galvanized metal such as aluminum – that covers that top of the chimney chase and seals around the top of the flue. Because they are made out of metal, chimney chase covers may rust over time; staining on the sides of a chimney chase is often the first sign that the chase cover has begun to rust.


The damper is located at the top of the firebox between it and the flue and can be opened and closed using a pulley or lever when the fireplace is in use. Dampers should be opened when the fireplace is in use to allow smoke and gas to vent up the chimney; when not in use, dampers should be closed to prevent conditioned air from escaping.

Flue and flue lining

The flue is the metal pipes that create the venting system for the chimney; to protect the surrounding building materials, flues have liners made from materials such as clay tiles or stainless steel. Flues may need to be relined after damage or when a new fireplace is installed.

Learning about the anatomy of your chimney can help you understand the purpose and function of each chimney component. For more information about the anatomy of your chimney, contact Pristine Sweeps today!

By Aaron Woodward | Tagged with: Tags: , , | Leave a Comment