Smoke chamber parging and repair in Dover Shores West

How corbelled chamber walls step inward

In a corbelled chamber, every brick course is stepped inward past the course beneath it. Stacked this way, the courses form a series of small ledges that close the chamber toward the flue. The method is sound masonry, but the inside face ends up rough.

Every ledge is a place for soot, creosote and mortar crumbs to rest. That is why the code asks for corbelled chamber walls to be parged smooth, and why stepped chambers are the usual candidates for parging.

How deposits build up on rough walls

Smoke cools as it rises through the chamber, and some of what it carries condenses on the walls. On a rough or stepped surface, those deposits have ledges and pockets to collect in, and each fire adds a little more.

A heavy layer changes the chamber shape and hides the masonry underneath. It also has to come off before any repair. Parging leaves a surface that is easier to brush clean at future sweeps, which is one of the practical reasons homeowners choose it.

Coating all four walls

The maker's directions call for application to all four sides of the smoke chamber, so that the cured material forms a self-supporting dome. A coat on one wall only leaves the other three rough, and the chamber stays uneven.

For that reason, our chamber quotes cover the full interior by default. Spot repairs are still possible when a chamber is already parged and sound, and we say so when the findings point that way.

What to keep out of the firebox

What you burn shows up in the chamber. The same coating's warranty conditions rule out burning driftwood, wood or pellets treated with preservatives, treated lumber, plastic and household trash in the repaired fireplace.

Those are sound habits for any masonry fireplace. Dry firewood and small, well-tended fires leave less residue on the chamber walls, and they keep the coat in good condition longer. We are glad to talk through fire-building habits at the walkthrough.

Protecting the room before chamber work

Chamber repair brings soot, mortar dust and wet material close to your living space. Before any tool comes out, we lay covers from the entry to the hearth and seal the fireplace opening around our work area.

Furniture near the fireplace is moved or covered with your permission. At the end of each day, the covers come up clean and the room is ready to use, even while the chamber is still curing.

• Floor covered from entry to hearth
• Fireplace opening sealed around the work
• Room left usable at day's end