Family-owned chimney repair serving Vista Park

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

Stucco on a chimney, over masonry or over framing

A stucco chimney can hide two very different structures. Some are brick or block with cement plaster applied straight onto the masonry. Others are wood-framed chases wrapped in lath and plaster, sometimes around a factory-built metal chimney. From the yard they look alike.

Under the Florida Building Code they are built differently. Plaster over lath goes on in at least three coats, over corrosion-resistant lath with a water-resistive barrier behind it. Plaster applied directly to masonry takes at least two coats. That backing decides how a crack is cut out, what sits behind the patch and whether water can reach wood.

Looking at the top of the chimney, the firebox and the attic run usually shows which kind you have. The backing is named on the written estimate for homes in Vista Park before a repair is chosen, since a framed chase with wet sheathing needs a different scope than stucco over solid brick.

Open mortar joints between flue tiles

A clay flue is only as tight as the joints between its sections. The Florida Building Code specifies medium-duty, water-insoluble refractory mortar with tight joints left smooth on the inside, and only enough mortar to make each joint and hold the liners in position.

Joints can erode, crack or drop out, leaving a gap between two sound tiles. Heat and flue gases then reach the chimney walls behind the liner, and water running down the flue finds another way into the masonry. Mortar left lumpy on the inside face works against the smooth surface the code asks for.

How the repair goes depends on how many joints are open, how high they sit and whether the tiles around them are sound. Scattered gaps in a good liner and a flue with failing joints along its length lead to different jobs. Each flue is written up with the joint condition found and the repair chosen for it.

Where a stovepipe enters the chimney

When a stove or other appliance connects to a masonry chimney through a wall, the pipe enters the flue from the side through a thimble. Under the Florida Building Code, that thimble is fireclay, rigid refractory material or metal, and it keeps the connector from pulling out or reaching past the inside wall of the liner.

Trouble shows up at that joint. Mortar around the thimble cracks and falls out, the thimble works loose or the connector was pushed in so far that it blocks part of the flue. Soot or stains around the opening on the room side are a sign the seal has failed.

The fix depends on what failed. A loose thimble is reset in the masonry, a damaged one is replaced and a connector that goes too deep is cut back to the liner face. Homeowners in Vista Park see the thimble, the connector and the flue behind them written as separate repairs.