We might start sounding like a broken record after a while, but the truth is the truth: Moisture is your chimney system’s worst enemy. Sure, we have to consider other potential chimney problems in providing proper chimney care, like fire hazards and proper draft. But when Mountain Man Fireplace and Chimney technicians are called out for chimney repairs, more often than not, the culprit behind that repair need is water.
How Water Damages Your Chimney
Here’s the thing about the various sources of chimney trouble: Most of them are either irregular, or relatively avoidable. Yes, a lightning strike could cause serious damage to your chimney, but those don’t happen frequently. Same goes for seismic events. And while a chimney fire is a serious concern, we can do a lot to make those far less probable, from sweeping your chimney every year to guiding you toward proper burning practices (like always and only burning seasoned or kiln-dried firewood).
Water, on the other hand, is consistent. Season after season, year after year, rain, snow, sleet and other forms of precipitation bear down on your chimney exterior, wearing at the masonry and the various components of your system. You can’t keep your chimney clear of moisture, but you can know how moisture attacks and damages your chimney, and learn what you can do to protect the system and avoid extensive damage.
3 Types Of Water Damage
Many components of your chimney system are made out of metal, including your chimney flashing and chimney cap. In pre-fabricated chimney systems, you’ll have a metal chimney chase installed at the top performing a job similar to that of a masonry chimney crown: diverting water away from the flue opening. Depending on what those components are made of, rust and corrosion could be a concern. Galvanized metal is a budget-friendly material, but it doesn’t stand up to the elements nearly as well as copper or stainless steel. Galvanized caps and covers can start to fail even in just a few years. Rust and corrosion are things we’ll look for during your chimney inspection, but if you see rust streaks on your chase cover or chimney cap or notice damage on your flashing in between inspections, call Mountain Man — those components likely need replacing.
Spalling masonry is masonry that’s flaking, chipping or crumbling, and that can span from surface flaking on your chimney crown to bricks that look like their faces have popped clean off. And yes, water is your culprit here too. Water causes spalling often through the freeze/thaw cycle — moisture weaves its way into small imperfections like cracks, then the water freezes as the temperatures drop, and expanding ice breaks open the masonry from the inside. But the regular assault of rain and snow can just slowly wear at your masonry too, causing the surface to flake and crumble.
Mortar Joint Damage
Bricks will generally stay stronger longer than the mortar joints holding them together. So after years of being bombarded by precipitation, it’s common for mortar joints to recede or crack, allowing moisture to move toward the interior of your chimney, affecting other components (like rusting your throat damper or wearing down the mortar joints in your firebox). Leaks like these can also create a mold issue. Mold feeds on moisture, and if it starts growing in your chimney, it can contribute to health problems, from skin irritation to respiratory problems, for the people in your home
How To Keep Water From Ruining Your Chimney
Your chimney system was designed with components that protect it against water. Your chimney crown or chase cover usher rain away from the flue; flashing keeps water from intruding where your chimney meets the roofline; a chimney cap helps protect the flue opening from letting precipitation in. When Mountain Man technicians perform your annual chimney inspection, we check all of those components to ensure that they’re performing properly and effectively — and if they’re not, we can do the right repairs to change that. So keeping up with those inspection appointments: a big step toward keeping water from ruining your chimney.
Another proactive step we can recommend is having Mountain Man techs apply a waterproofing sealant to your masonry. Waterproofing keeps excess moisture from being absorbed, and protects the masonry itself, helping to extend its service life. It’s a really worthwhile extra step that helps you avoid damage and leaks, and care for a beautiful part of your home.
If you have any questions about moisture damage to your chimney — or if you’d like to make an appointment with Mountain Man Fireplace & Chimney’s CSIA-certified technicians — just give us a cal