Thinking of moving the hole for the flue collar and simultaneously removing the cleaning hatch that's currently at floor level. A new floor will be placed over the old one, which would end up 15 mm above the lower edge of the cleaning hatch. Additionally, the old floor is moisture-damaged right at the hatch. Is it then a matter of simply chiseling it out, bricking from the inside out with concrete blocks or bricks, and then filling the chimney with leca pellets up to the flue collar?
Are there other ideas or tips?
