Why Chimney Flashing is One of Your Chimney’s Most Critical Components

Chimney flashing often is one of those “out of sight, out of mind” things. You never see it unless you climb up on your roof, it doesn’t make noise, and as long as it works as it should, you don’t even know it’s there. When it stops working as it should, that’s when some serious problems can start. Here’s what you need to know about this critical component of your chimney system.

Chimney Flashing 101

Flashing is the material, usually sheet metal, that wraps around the base of your chimney and seals the gap between it and your roof.

Installing flashing is a two-part process. First, an L-shaped step flashing is laid down against the sides of the chimney and the roof. This is followed by installing counter-flashing, which is embedded into the mortar joints and folded down over the step flashing.

When flashing is properly installed and correctly sealed, it forms an impenetrable barrier to keep rainwater and melting snow out of your home.

The dangers of water infiltration through the chimney/roof gap

If chimney flashing is warped or rusted out, or if there is no flashing at all, water has a clear path to move down into your home. This intrusion will affect not only home building materials but also the external masonry of the chimney.

Wallboards, ceilings, insulation, rafters, and other parts of the home can be severely damaged because of inadequate chimney flashing. Any wooden material will absorb water and begin to rot and harbor the growth of dangerous mold. The materials that make up the roof also can rot and decay. Metal objects can rust. Additionally, infiltrating water can begin a cycle of masonry decomposition that can result in a collapsed chimney or a house fire.

How flashing becomes damaged

Flashing made from quality material and installed properly will serve you well for many years. However, it won’t last forever, and certain things can decrease its lifespan and serviceability such as:

• Lightning strikes
• Settling of the house or the chimney footing
• Earthquakes
• Rust
• Season after season of searing summer temperatures and freezing winter weather

How to ensure your chimney flashing is always in good shape

The best way to keep your flashing working as it should is to have it looked at as part of an annual chimney inspection. CSIA-certified inspectors can quickly tell if your flashing needs repair or replacement. You can do periodic inspections yourself, checking for loose areas, warping, rust, gaps, and faulty seals. Having your chimney flashing repaired or replaced isn’t a complicated or expensive job, but it’s a task that can save you thousands on chimney repair and home repair bills. Don’t let “out of sight, out of mind” flashing make you go out of your mind paying for huge repairs that easily could have been prevented.

Is it time to schedule an annual chimney inspection for your entire chimney system? Felgemacher Masonry & Chimney has served the greater Buffalo, NY, and Rochester, NY, regions for more than 60 years with trusted chimney repair, chimney sweeping, and chimney inspection services.

Keep your chimney safe by calling (716) 907-4914 in the Buffalo area or (585) 308-4914 in and around Rochester.