Chimney Caps and Crown Repair in Genola

Multiple flues want one cover

A stack serving a fireplace, a furnace and perhaps something long disconnected will often have two or three separate clay tiles poking out of the crown. People cap those individually with small caps, one per flue, and it half works. The tiles are protected and the crown between them is not, so water keeps landing on the concrete, running into the hairline cracks and getting into the top courses of brick. A multi-flue cover is a single stainless lid spanning the whole top of the stack, standing off on legs so each flue still breathes, with mesh around the sides. It protects every flue and the crown underneath at the same time, which is what you actually want on an old chimney. It also lets us deal with an abandoned flue properly, sealing it at both ends rather than leaving it as an open hole collecting rain.

The mesh matters here for the ordinary reasons. It keeps birds out of the flue, and it works as a spark arrestor. It also keeps the flue from filling with wind-carried leaf litter and orchard debris, which in this part of the valley is a genuine seasonal nuisance rather than a theoretical one.

On an old Genola farmhouse the flue nobody can account for is usually a furnace or water heater connection from a fuel the house stopped burning decades ago. Sealing it properly at both ends while the cover is going on adds very little to the work and closes a hole that has been taking rain and snowmelt straight into the stack for years.

The crown is where the money goes further

The crown is the concrete surface on top of the stack that everything else sits on. A well-built one slopes away from the flue tiles, projects beyond the face of the brick, and has a groove underneath so water drips clear instead of running down the masonry. A great many old ones are none of that: a flat pad of mortar finished flush with the brick, which delivers every drop of rain and every bit of snowmelt straight onto the wall below. Once it cracks, water goes in at the top and works downward for years.

Sound crowns with hairline cracks can be sealed with a flexible coating made to move with the concrete. Crowns that have broken up, sunk, or never had an overhang need recasting, and it is usually the highest-value single repair available on an old chimney because it stops the cause rather than treating the symptoms.

Waterproofing the brickwork afterwards is worth doing on an exposed stack, with a vapor-permeable repellent that blocks liquid water but still lets the wall dry outward. The sequence is fixed and it is not marketing: crown first, flashing second, cap third, sealer last. Applied to a chimney still taking water at the top, a repellent traps the moisture inside and the next hard freeze does more harm than doing nothing would have. If your fireplace sits unused most of the year, ask us about a top-sealing damper at the same time, because a gasketed damper at the top of the flue stops the cold draft an old throat damper never sealed against. Licensed and insured.