Brick chimney with a snow-covered crown on a winter roof
Chimney Repair & Rebuilds

Chimney Flashing vs. Chimney Crown: Where Leaks Around Your Chimney Really Start

Chameleon Masonry
•
October 14, 2026

Water stains on the ceiling near your fireplace, damp drywall in the attic or a musty smell after rain are all signs that water is getting in around your chimney.

The tricky part is figuring out where. Two of the most common sources are the flashing and the crown. They are both at the top of the chimney, but they do very different jobs and fail in different ways.

Here is how to tell them apart and why it matters for the repair.

What Chimney Flashing Does

Flashing is the metal that seals the joint between your chimney and your roof. Because the chimney passes through the roof, there is always a seam where water can get in. Flashing covers it.

A proper flashing system usually includes:

  • Step flashing woven in with the shingles along the sides of the chimney
  • Counter flashing set into the mortar joints of the chimney and lapped over the step flashing
  • A cricket or saddle on the uphill side of wider chimneys to divert water and snow around them

Signs of Flashing Problems

Flashing leaks often show up as:

  • Water stains on the ceiling or walls right beside the chimney
  • Wet or stained framing in the attic along the chimney sides
  • Flashing that is lifted, bent or pulled away from the brick
  • Heavy layers of roofing tar or caulking used as a patch
  • Rust or holes in the metal
  • Leaks that are worst during wind driven rain or snowmelt

A very common issue is counter flashing that was simply caulked to the face of the brick instead of being set into the mortar joints. The caulking dries out and water runs straight behind it.

What the Chimney Crown Does

The crown is the slab that covers the top of the chimney around the flue. Its job is to keep rain and snow from soaking down into the masonry.

A properly built crown should:

  • Slope away from the flue
  • Overhang the brick on all sides
  • Have a drip edge underneath so water falls clear of the chimney
  • Be built from a durable mix designed for exterior exposure

Many crowns are instead a thin layer of mortar trowelled over the top of the bricks. These crack quickly and let water straight into the chimney.

Signs of Crown Problems

Crown damage usually shows as:

  • Visible cracks across the top of the chimney
  • Pieces of crown breaking off
  • Spalling or crumbling bricks near the top of the chimney
  • White staining down the chimney sides
  • Water in the firebox or damper area
  • Rusted damper parts

Crown leaks often appear inside the chimney or fireplace, while flashing leaks usually show up on ceilings and walls beside it.

Why the Difference Matters

It is common for homeowners to have the roof patched around the chimney when the real problem is a cracked crown, or to reseal the crown when the flashing is the issue. The leak continues and so does the damage.

In some cases, it is neither. Water can also enter through:

  • Failing mortar joints on the chimney
  • Porous or spalling brick
  • A missing or damaged chimney cap
  • Cracks in the chimney walls

That is why a proper inspection looks at the whole chimney, not just one part.

How These Repairs Are Done

Flashing repair may involve resealing or replacing sections, cutting counter flashing properly into the mortar joints, or adding a cricket on wider chimneys. Masonry and roofing work often need to be coordinated.

Crown repair depends on the damage. Small cracks can sometimes be sealed with a product made for crowns. Badly cracked or poorly built crowns are usually removed and replaced with a properly formed crown with an overhang and drip edge.

Why Fall Is the Time to Fix Chimney Leaks

Water that gets into a chimney before winter freezes and expands inside the masonry. A small leak in October can mean cracked brick and crumbling mortar by spring. Repairing the flashing or crown now helps prevent much larger chimney repairs later.

Chimney Repair in Barrie and Simcoe County

Chameleon Masonry repairs chimney crowns, rebuilds damaged chimney masonry and corrects leaks for homeowners across Barrie, Simcoe County, Innisfil, Orillia, Muskoka and the northern GTA.

We inspect the full chimney to find where the water is getting in, then recommend the right repair.

Contact Chameleon Masonry today to request a quote for chimney leak repair.

View Articles

Contact Us For A Free Consultation

Have questions or ready to start your masonry restoration project? Our dedicated team of masonry experts are here to help. Whether you’re exploring historical restoration, custom masonry modifications, or need expert brick repair, we’re just a call or click away.

Get Free Quote
Bricks, a mason's trowel and a yellow hard hat