Repairing chimney caps and crowns on Vancouver, WA roofs

The crown is the sloped slab of mortar or concrete that tops a brick chimney around the flue. Its job is to shed water off the top and past the edges of the brick. Many crowns were built as a thin smear of mortar with no overhang, and after years of wet winters they crack, separate from the flue tile and let water soak straight down into the chimney.

The cap is the metal cover over the flue opening, usually with a mesh screen around the sides. It keeps rain, birds, squirrels and needles out of the flue. Framed chimneys with metal flues have a chase cover instead, a sheet-metal pan across the top of the wood box. When any of these fail, the leak can look exactly like a flashing problem from inside the house.

How chimney tops let water in

A crown cracks because mortar and brick move at different rates as they get wet and dry, and the occasional freeze in our winters widens any gap that is already there. Once water gets through, it travels down inside the brick and the chimney chase. It can show up as a stain on a ceiling several feet from the chimney or as damp, crumbling brick in the attic. Homeowners often pay for new flashing first and still have the leak.

Caps fail in simpler ways. Cheap galvanized caps rust through at the seams in our climate. Wind lifts poorly fastened caps right off, and a fir limb can crush one. Without a cap, rain falls straight down the flue, where it rusts dampers, wets the smoke chamber and can drip into the firebox. On framed chimneys, a flat chase cover holds puddles that eventually rust through and leak into the wood framing.

Repair options for caps, crowns and chase covers

We match the fix to what failed. A sound crown with fine cracks gets cleaned and coated. A crown that is broken, loose or built too thin is removed down to the brick and recast. Caps and chase covers are measured on the roof and replaced with units sized to the flue and the chimney top, so they fit tight and do not rattle in the wind.

• Crown crack sealing with a flexible crown coating
• Full crown rebuild with an overhang and drip edge
• Single-flue and multi-flue cap replacement
• Stainless chase covers with a sloped top
• Mesh screens to keep birds and animals out
• Mortar touch-up on the top courses of brick

What our crews do and what a chimney sweep does

Our work is the outside top of the chimney and its connection to the roof. We rebuild crowns, replace caps and chase covers, repoint the top few courses of brick when they are loose, and check the flashing and cricket while we are up there. If the flashing also needs work, we price it separately so you can see each cost and decide what to do first.

What happens inside the flue is a chimney sweep's job. Liner damage, creosote buildup, cracked flue tiles below the top and damper problems all belong to a sweep. If we see signs of those while working on the crown, such as broken tile pieces or heavy soot staining, we tell you and suggest having the flue looked at before the next time you light a fire.

When to remove the chimney instead

Not every chimney is worth fixing at the top. If the fireplace is no longer used, the brick is spalling well below the crown and the chimney leaks from several places at once, it may cost less over time to take it down below the roof line and patch the roof. We will give you both prices when that is a real option, so you can compare a crown rebuild against chimney removal.