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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!


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!