Chimney flashing and waterproofing in Lake Forest, IL
Most chimney leaks do not start in the chimney. They start where the chimney meets the roof.
Flashing is the metal that seals the joint between the chimney and the roof. It is one of the most common places for a leak, because two different materials meet there and move at different rates through the seasons. When the flashing or its sealant fails, water slips behind it and into the attic.
If you have a stain on a ceiling near the chimney, a damp smell in the attic or peeling paint on a wall next to the fireplace, flashing is one of the first things we check. We also look at the crown, the brick and the cap, because a leak can have more than one source.
What we may do about a leak
- Re-sealing or replacing flashing that has lifted, rusted or separated
- Adding or correcting counter-flashing so water sheds properly
- Repairing the crown, cap or brick if they are letting water in too
- Applying a breathable water repellent made for masonry, when it suits the brick
- Explaining what is a chimney problem and what may be a roof problem
Clues the flashing may be failing
- A water stain on the ceiling or wall near the chimney
- Dampness or mold in the attic around the chimney
- Rusty, bent or gapped metal where the chimney meets the roof
- Cracked or missing sealant along the flashing line
- Efflorescence, the white powder on brick that means moisture is moving through it
A word of caution: coating a chimney with the wrong product can trap moisture in the brick. If someone suggests a thick paint-on sealer, it is worth asking whether it breathes. We prefer to find the leak first and treat the real cause. See also chimney repair and masonry.
Questions we hear
How do I know the leak is the chimney and not the roof?
Sometimes it takes a closer look. Chimney flashing leaks usually show up near the chimney and mostly during rain. We will tell you if we think the roof is the real source.
Does waterproofing the brick stop all leaks?
No. Leaks often come from flashing, the crown or the cap. Waterproofing helps the brick itself but is not a cure for those.
Can this wait until spring?
Water damage is usually progressive. If you see a stain, it is better not to wait long.
Do you do roof repairs?
Our focus is the chimney. If the roof itself is the problem, we will say so and suggest you call a roofer.
Other services
Tell us what you’re seeing
Leave your name, number and a few words about the chimney or fireplace. We read every request and call you back. If it is urgent, call us instead: (224) 271-0137.