Chimney repair with a free inspection in Monterey

Where the flue liner meets the crown

A flue liner should stand up out of the crown rather than stop flush with it. BIA guidance shows the liner extending above the top of the cap, and the Florida Building Code requires a caulked bond break around any flue liner at the cap.

The point of a bond break is that the liner and the cap stay separate pieces. BIA guidance has the cap and liner interface thoroughly primed, backed and sealed to reduce the potential for water getting in. Solid mortar packed tight against the liner locks the two into one rigid piece, and a rigid joint that cracks opens a path for water right beside the flue.

This joint gets its own look on every chimney. The fix is written as a separate item, apart from any work on the crown surface.

• Cracked mortar packed against the liner
• A missing or split sealant bead
• A liner that stops at or below the crown surface

A chimney with more than one flue

Some chimneys carry two or more flues, one for the fireplace and others for a second fireplace or an appliance. Under the Florida Building Code, masonry wythes separate adjacent flue linings, built into the chimney walls, with an exception for two flues venting a single appliance.

Each flue brings its own top detail, and the masonry between flues cannot be seen from the roof, so every flue is checked from its own top. A cap over one flue with its neighbor left open still lets rain into the chimney.

Every flue gets its own findings on the estimate. That makes it clear which flue a repair belongs to, what that flue serves and whether a problem in one affects the use of the other.

• A liner standing above the crown
• Its own caulked bond break at the crown
• A cap that covers the flue it is meant to protect
• The top of the wythe beside it, as far as it can be seen

Counterflashing set into the mortar joint

How the top edge of the counterflashing is held decides how long it stays tight. BIA guidance sets its edge 3/4 to 1 inch deep in a mortar joint, mortared in solid, so the metal is locked into the masonry itself.

One shortcut is a strip of metal fastened to the face of the brick with a bead of caulk along its top edge. A surface-mounted strip depends entirely on that bead. Once the caulk cracks or pulls away from the brick, water runs down behind the metal and into the very joint it was meant to protect.

Cutting the joint, setting the metal and mortaring it back in takes more time than a caulked strip. It is the detail we price on flashing jobs. The estimate says whether the counterflashing will be set into the joint and which joints are cut and remortared.

After a chimney fire, keep the chimney out of use

Creosote is a black or brown combustible residue that forms when smoke condenses on the cooler walls of a flue. DuraVent's chimney instructions describe ignited creosote as an extremely hot fire, and they say not to use the chimney again until it has been inspected for possible damage.

If a fire is burning in the chimney now, get everyone out of the house and call 911. Nothing about the flue matters until the fire department says the house is safe.

Once it is out, the flue stays unused until that inspection is done. It looks for cracked or displaced flue tiles, open joints, damage to the smoke chamber and damper, heat damage at the top and anything scorched where the chimney meets framing. Our chimney inspection service handles that work, and each repair it finds is priced on a written estimate.