Our Company Blog

Leaky Chimneys

Don't let a small chimney leak turn into a massive repair job

Don’t let a small chimney leak turn into a massive repair job

After a long winter, the warmer temperatures and milder weather of spring is a welcome reprieve. Unfortunately, April showers may bring more than May flowers – they may cause your chimney to leak.

The symptoms of chimney leaking can take a number of forms, ranging from a damp or moldy smell, water damage to walls or ceilings, or a tell-tale dripping noise when it rains. No matter what symptoms of water entry your chimney is exhibiting, it is important to have it inspected and repaired as soon as possible.

Causes of chimney leaks

Although chimneys look simple, they are actually complex structures with a number of different parts that work together to protect your fireplace and flue from water entry. However, because chimneys are directly exposed to the elements, they often deteriorate faster than your fireplace itself.

While pinpointing the exact point of water entry can be difficult, the following are some of the most common causes of leaky chimneys.

Chimney cap: The chimney cap covers and protects the top of the flue against water, animals, and debris such as leaves or branches. Chimney caps that are not sized correctly, were incorrectly installed, or have been damaged may begin allowing water in. Likewise, some older homes – especially those that do not receive regular chimney maintenance – may be missing chimney caps entirely.

Chimney crown: The chimney crown is the slab of masonry or concrete that covers the top of the chimney. Chimney crowns should never be flush with the masonry of the chimney; an overhang is necessary to prevent water from flowing directly onto the bricks and mortar. Likewise, good chimney crowns are also angled to protect water from pooling – and therefore damaging – the crown.

Flashing: Flashing is a weatherproof strip that seals the seam between the chimney and the roof. If you’ve had your roof recently repaired or replaced, you may want to check the flashing; most roofers are not equipped to adequately install flashing and may use the wrong materials or too many nail holes, both of which can cause flashing to leak.

Masonry damage: Because chimneys are exposed to the elements, they can very quickly deteriorate when damaged. This is especially true of water damage  which can cause bricks to crack and spall in as little as one year.

Preventing leaky chimneys

The most important thing homeowners can do to prevent a leaky chimney is to have regular maintenance performed. Regular maintenance such as chimney sweeps and inspections ensure that small problems are caught and repaired early before they can turn into major issues.

In addition to regular annual maintenance, having a waterproof sealant applied to your chimney is another way to prevent water damage. These professional-grade products are specially designed for use on fireplace and chimney masonry; by allowing the brick to retain its permeable properties, water and gas are not trapped inside the brick.

Don’t let a leaky chimney ruin your spring – contact  Mountain Man Fireplace and Chimney today to have your chimney leaks repaired! We serve in and around Littleton, CO, so visit our service area page or give us a call for more information.

By Jake Johnson on April 24th, 2015 | Tagged with: Tags: , | Leave a Comment

When is a Chimney Not a Chimney?

Part Two of ‘Why is MY Chimney Leaking?’  

There are quite a number of ambiguous and even confusing terms used in the hearth industry.  Among them is the very basic word ‘chimney’.  If what looks like a chimney and sticks up out of your roof is covered with siding or stucco, it’s probably actually a ‘chase’.  The chase is the framed box and it’s the metal pipe inside that is the chimney.  But all this does is lead to the same questions we answered last month – why is my chimney leaking?  Or my chase or whatever you want to call it?!?!?

In order to safeguard performance and all who live in your home, you must take steps to waterproof your chimney.

In order to safeguard performance and all who live in your home, you must take steps to waterproof your chimney.

Water leaking into your home is a hassle and it can be difficult to locate the source.  Whether you’re venting a fireplace, a stove or even a furnace; the fundamentals of investigating a leak on are the same with a chase as with a chimney:  start at the top and work down to the roofline.  Usually the chase is covered by a sheet metal cover that was fabricated for that specific chase – it looks like an upside down cake pan.  In order to keep it from leaking, the ‘chase cover’ needs to be properly supported and sized for whatever chimneys pass through it.  A properly installed chase cover consists of four components:  the underlying framing and plywood to support it, the cover itself – it should have 4” sides and a drip edge, the chimney collar – the transition from flat to round, and the storm collar – the hat brim-shaped strip of metal that fits around the outer wall of the chimney above the chimney collar.

If water leaks into the chase cover from the top, it typically runs down the outside of the pipe until it reaches something to absorb it.  That can be the ceiling, the top of a freestanding stove or even the walls on the front of a fireplace.  It’s also common for water leaking into the chase to eventually create rust on the top of a built-in fireplace, causing a serious deficiency in the ability of the fireplace to protect the surrounding combustible material.

Because the chase is built very similarly to a standard wall, the sides of a conventional chase are the easiest to evaluate during a leaky chimney diagnosis.  Like anywhere else on your home, water can enter through gaps and/or splits in the siding, cracks in the stucco, and even through holes made by animals.  A comprehensive chimney inspection will include an evaluation of all four sides of the chase.

Where the chase 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/chase, we evaluate the entire chimney/chase as a system: top (cap and cover), middle (siding and/or stucco) 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.  Our standardized 20-point inspection process is designed to locate the source of leaks and allow us to create a repair program for stopping the water penetration into your home.

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!

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!