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What Causes Chimneys to Leak?

Chimneys are designed and built to withstand constant exposure to the elements. However, even the best built chimneys can be damaged or deteriorate over time. Chimney damage often leads to chimney leaks; with so many different components, it can be difficult to determine the exact cause of a chimney leak.What Causes Chimneys to Leak

Causes of chimney leaks

Diagnosing the cause of a leaky chimney can be difficult; because of this, we recommend having a chimney inspection done by a certified professional to identify the cause of the lea. Finding and repairing the source of the chimney leak first can prevent additional water from getting in after chimney repairs are made. The following are four of the most common causes of leaky chimneys.

– Chimney cap: The metal top and mesh sides of the chimney cap keep moisture, animals, and debris out of the chimney. However, if the chimney cap is improperly fitted, incorrectly installed, or damaged, water can easily flow into the top of the flue and down into the rest of the fireplace system.
– Chimney crown: The stone or masonry of the chimney crown is the slab that surrounds the flue and covers the top of the chimney structure. Because of their location, chimney crowns often bear the brunt of the chimney’s exposure to the elements; this can cause them to deteriorate faster than other chimney components. When this occurs, water can seem into cracks or holes in the chimney crown.
– Flashing: Chimney flashing creates a watertight seal on the joint between the roof and the chimney. Flashing can lose its seal due to overexposure to the elements, damage from storms, changes to the surrounding roofing materials, or improper installation. Leaks caused by flashing are often misidentified as roof leaks because the water appears on ceilings and walls instead of inside the chimney.
– Masonry: Water from rain, ice, snow, and even sprinklers can cause masonry to deteriorate over time. Damaged masonry can chip, crack, and spall because of overexposure to moisture. Not only does this let water into the chimney, but it can also affect the structural stability of the chimney structure.

How to prevent chimney leaks

While it is impossible to keep your chimney away from water, it is possible to help prevent chimney leaks. One of the easiest – and most important – ways to prevent a chimney leak is by having regular sweepings and inspections. This annual maintenance allows minor chimney problems to be identified and repaired long before they create serious damage.

In addition to regular annual maintenance, masonry can also be waterproofed in order to prevent water damage. During the waterproofing process a specially designed water repellant is applied to the masonry; this allows the bricks and mortar to retain their semi-porous nature without letting water be absorbed by the masonry. Waterproofing may also be able to stop the deterioration process on chimneys with existing water damage.

If you have a chimney leak – no matter how small – don’t wait for the leak to get worse before calling a chimney sweep. Contact Mountain Man Fireplace & Chimney today to schedule an inspection; our certified technicians can find and repair the source of your chimney leak!

By Jake Johnson on June 21st, 2016 | Tagged with: Tags: , , , , | Leave a Comment

What’s A Chimney Crown And Why Is It Important

When it comes to their chimney, many homeowners wrongly assume it is a singular structure. However, chimneys are actually complex structures with a number of different parts that all work together to keep your fireplace system functioning. One of the often forgotten chimney components is the chimney crown; even though you may not pay it much attention, the chimney crown has an important function.

What’s a chimney crown?What's a Chimney Crown and Why is it Important - Evergreen CO - Mountain Man Fireplace and Chimne

The chimney crown is the masonry or concrete slab that covers and seals the top of the chimney. The top of the flue extends through the top of the chimney crown, which is then covered by the chimney cap. Chimney crowns play an important part in protecting the chimney system against water damage by keeping moisture from ice, rain, sleet, or snow out of the chimney.

Well-constructed chimney crowns should be made of concrete as this is the most resistant to moisture. Likewise, chimney crowns should be slightly sloped or domed to prevent moisture from building up on top of it around the top of the flue. Lastly, chimney crowns often have a lip of two to two and a half inches; this edge, known as a kerf, prevents water from flowing from the chimney cap directly onto the sides of the chimney structure. Instead, it drains harmlessly onto the roof.

What causes chimney crowns to deteriorate?

Even if the rest of the chimney structure is sound, the chimney cap may be damaged or need to be repaired. This happens because chimney crowns often bear the brunt of the elements. Because they are flat or slightly sloped, snow and moisture are able to accumulate on the chimney crown; the masonry of the chimney itself is often saved from this kind of deterioration because of its straight vertical sides.

Another major issue that can occur with chimney crowns is deterioration due to the building material. Chimney crowns should never be mortar based or constructed using brick. Both of these building materials are too porous to be able to effectively keep water out of the chimney. Chimney crowns should be made of concrete – or in some cases metal – as it is best able to withstand moisture without being damaged.

 

Chimney crowns can also be damaged by exposure to changes in temperature. During the winter, for example, the flue itself may be extremely hot even when the masonry of the chimney is cold. This temperature difference can cause the chimney crown to expand and contract, losing the seal around the flue and potentially letting moisture into the chimney.

Why is a chimney crown important?

A well maintained chimney crown is an important part of keeping your entire chimney system in good condition. Without it, moisture can enter the chimney structure, putting everything from the flue to the firebox at risk for water damage. Chimney crowns are checked for signs of damage or deterioration during your annual chimney inspection; to schedule your chimney inspection, contact Mountain Man Fireplace & Chimney today!

By Jake Johnson on December 15th, 2015 | Tagged with: Tags: , , , | Leave a Comment

Chimney Crowns Aren’t Just For Aesthetics

Chimney crowns do more for your chimney than you might expect!

Chimney crowns do more for your chimney than you might expect!

Many homeowners falsely believe that their chimney crown is just for aesthetics and that the chimney cap does the majority of the work of protecting the flue. However, the chimney crown is an equally important piece of the chimney that needs the same level of care and upkeep as the chimney cap.

What is a chimney crown?

A chimney crown is a concrete or masonry slab that covers and protects the top of the chimney. The chimney crown is uniquely important in that it protects both the interior and exterior of the chimney. Because of this, chimney crowns should be both functional as well as aesthetically pleasing.

Features of a chimney crown

There are several key features that a chimney crown needs to have in order to function correctly. One of the most important features of the chimney crown is the overhang. Also known as a drip ledge, the overhang should extend an additional 2 to 2.5 inches on all sides of the crown. The overhang prevents water from flowing directly onto the masonry of the chimney, protecting the bricks and mortar from being constantly assailed by water and moisture.

Another important chimney crown feature is the building material used to construct the crown itself. Many chimney crowns, especially those installed by general contractors or masons without experience, are not made of the right materials. While bricks and mortar can be used for the chimney, they should never be used for a chimney crown as they are too porous to serve as a long term protection against moisture. Instead, chimney crowns should be made of a solid slab of concrete, metal, or stone.

Maintaining your chimney crown

Just like the rest of your chimney system, the chimney crown should be regularly inspected to check for cracks, leaks, or other signs of damage or deterioration. Likewise, if you begin experiencing chimney leaks or leaking around interior ceilings or walls, the chimney crown should be checked as soon as possible.

If your chimney crown has begun to deteriorate but is not yet seriously damaged, a specially designed waterproofing product may be able to be applied. These products are specially designed for use on masonry and chimneys and can prevent further or future water damage. Likewise, waterproofing can always be used as a preventative measure against water damage even if your chimney crown is not damaged.

In addition to maintaining your chimney crown, your chimney cap and chimney flashing should also be regularly inspected, maintained, and repaired as needed. Together with the chimney crown, these three chimney components play an important role in protecting your chimney, fireplace, and home against water damage. If any other part of the chimney is damaged, water may be able to find its way in.

If you live around Littleton, CO and you’re worried that your chimney crown is more aesthetic than functional, contact Mountain Man Fireplace and Chimney today. Our expertly trained technicians can evaluate the condition of your chimney crown and help make it both a beautiful and functional part of your chimney.

By Jake Johnson on May 8th, 2015 | Tagged with: Tags: , , | Leave a Comment

Keep the Water Out

Look Up: Preventing Leaks Can Start At The Top

Your chimney is a complex (and pretty remarkable) system, and every component plays an important role in its performance, safety and longevity. But when we get on the subject of understanding and preventing chimney leaks, it sometimes helps to start by looking up.

What do you need to do to ensure that your chimney stays dry? We have answers.

What do you need to do to ensure that your chimney stays dry? We have answers.

The top portion of your chimney, up above the roofline, tends to be both your chimney’s first line of defense against moisture intrusion and moisture damage and the most heavily bombarded part of your chimney — between rain, snow and baking sun. Making sure that all the parts of your chimney system that live above the roofline are in top shape goes a long way toward keeping chimney leaks at bay. And that’s something we want to help you do at Mountain Man Fireplace & Chimney, because chimney moisture damage is a serious, and seriously frustrating problem.

The Top Portion Of Your Chimney: A Breakdown

Chimney Caps

If you’re looking at your chimney from the street, the first thing you notice up at the very top should be a chimney cap. These are installed atop your flue opening, and their role is multifaceted: Chimney caps not only help to keep rain, snow and other forms of precipitation from diving right into your open flue, they also keep nesting animals out, which helps prevent a whole other kind of damage and annoyance.

If you don’t have a properly sized chimney cap at the top of your flue, that’s one big piece of prevention missing, and one big step closer to moisture problems in your chimney.

Chimney Crowns And Chase Covers

If you have a masonry chimney, you’ll have a masonry chimney crown built up top, right below where your chimney cap is installed. It’s in a tough spot — horizontal, in the direct line of sun and precipitation — and it does an important job, directing and diverting water away from your flue opening. Given all the stress your crown is under, it’s not uncommon for cracks to form. But once cracks do form, bigger trouble begins — moisture can make its way into small cracks, expanding as it freezes and more or less bursting the masonry apart from the inside. The longer it’s left uncorrected, the more damage occurs, and the more moisture gets a chance to make its way into the interior of your chimney and your home.

That’s part of why we’re so vocal about keeping up with your annual chimney inspections — if we’re checking your system closely each and every year, we’ll find those small cracks and make repairs before you’re left with a crumbled and spalling crown that needs to be completely rebuilt.

If you have a pre-fabricated or factory-built chimney system, you’ll have a chase around the upper portion of your chimney, topped with a chase cover that performs a role similar to a chimney crown. Chase covers are constructed with metal, so you’re not dealing with spalling masonry, but instead with the potential for rust and corrosion. Homeowners with galvanized metal chase covers most often have that problem — and rusty, corroded chase covers are a just about surefire contributor to a chimney leak.

If you notice rust streaks on your chase cover in between chimney inspections, give Mountain Man Fireplace & Chimney a call. We can replace the damaged cover with a new one, and talk to you about different options for materials, like stainless steel and copper, which are far more durable (and are beautiful, too).

Chimney Flashing

Where your chimney comes up through your roof, you have seams — the places where the horizontal roof butts up against your vertical chimney column. Seams in just about any context — from your chimney to your chinos — can mean vulnerability when care isn’t taken to strengthen them. So in a chimney, we install flashing all around the chimney, sealing off and carefully protecting those seams from moisture intrusion.

Since its role in leak prevention is so important, damaged flashing is a big deal — if pieces of flashing tear or come off in a storm, or corrode over time, the likelihood of ending up with a leak certainly isn’t low. If there’s a problem with your flashing, Mountain Man technicians can do the careful, custom work required to getting it back in shape.

If you have any questions about your chimney, from its design and function to the best ways to protect it (and your home), we’re always glad to help. Call Mountain Man Fireplace & Chimney!

 

Why is My Chimney Leaking?

There are few things more aggravating to a homeowner than having water leaking into their home. Finding the exact source of a leak around a chimney can be particularly frustrating.  The inherent complexity of having a masonry structure pass through a framed roof can turn the proper diagnosis of a leaking chimney into a time-consuming headache.

Annual chimney maintenance is helpful because it alerts you to problems early, before they become catastrophic.

Annual chimney maintenance is helpful because it alerts you to problems early, before they become catastrophic.

To understand the fundamentals of why a masonry chimney will or won’t leak, let’s start at the top of the flue and work down to the roofline.  First, if you don’t have a chimney cap, get one.  An uncovered chimney allows whatever rain and snow are falling to enter right into the fireplace flue.  Over time, that water erodes the mortar joints between the flue tiles and it also damages the chimney as the water is heated into steam during operation of the fireplace.

The chimney crown is the ‘lid’ over your chimney.  It’s useful to think of a chimney as a hollow box built out of cinder blocks or bricks.  To keep water from entering the chimney from above, a crown is poured.  The crown should be concrete that is 4” – 5” thick and contoured to drain moisture.  Lots of chimney crowns in our area were just built with mortar instead of concrete or they lack an expansion joint to allow the top flue tile to expand when the fireplace is in use.  The result is cracks and erosion that allow water to penetrate and cause increasingly larger cracks as the freeze-thaw cycle occurs.

The sides of a masonry chimney are often the least understood culprit when making a leaky chimney diagnosis.  Like all masonry materials, mortar joints will allow water penetration when saturated.  When the mortar joints are cracked or damaged, water easily flows through them and into the space between the cinder block structure and the stone veneer.  It flows downward until it reaches the framing of the roof and into your home.  Even in our dry climate, when a chimney is exposed to excessive rain and snow, it will absorb moisture through the rocks or bricks on the sides. The solution is to locate the weakened joints and cracked rocks and seal or replace them as necessary.

Where the chimney meets the roofline can be the most complicated region of a leaking chimney to diagnose.  Every roof-chimney interface should have an overlapping system that includes both flashing and counter-flashing.  The flashing starts under the roofing materials and runs up alongside the chimney.  The counter-flashing starts out with a ‘cut’ into the side of the chimney and then overlaps the flashing to create a barrier to water intrusion.  Unfortunately, a huge percentage of homes in our community have chimneys that are flashed improperly.  We often see chimneys where the counter-flashing is just placed along the chimney and ‘sealed’ with some type of goop.  WRONG!  Chimneys like these need significant repairs to keep the water out of your home.

To correctly diagnose and fix a leaking chimney, we evaluate the entire chimney as a system: top (cap and crown), middle (stonework or bricks) and bottom (flashing and counter-flashing).  If any of the three sections is leaking, then the chimney has a potential for water to enter the home.  Next month we’ll explain how to find the leaks on a framed chase with a factory-built chimney.

To schedule a fireplace/chimney sweeping and/or inspection – call us today at Mountain Man Fireplace and Chimney, Inc – (303) 679.1601 / 838.3882 or electronically at office@MtnManChimney.com.  Semper Fi!