Loose stones in my Greely house wall: can they be reset?

Loose stones in a house wall can be reset in some cases; whether that is the right repair depends on what is behind them and why they moved.

A mason will want to look at each stone closely before committing to a reset. The stone itself needs to be sound and durable; a stone that has delaminated or cracked through may need replacing rather than resetting. The mortar bed and the backing behind the stone matter too: if the cavity has filled with debris, if flashing or weep holes have failed and moisture has been sitting there, or if the ties holding veneer to the frame have corroded or pulled loose, resetting the face stone alone does not address what caused the movement. The Ontario Building Code (9.20.2.5.(1)) says "Stone shall be sound and durable"; a mason inspecting the wall can tell you whether the stones that came loose meet that standard.

On cost, there are too few published prices to quote a range for stone wall repair of this kind. Ask each mason for a written quote that covers the number of stones to be reset or replaced, the condition of the mortar bed and ties behind them, how joints will be cut out and dust controlled on site, the mortar type and how it will be matched to the existing wall, and cleanup and disposal.

A few things worth putting in writing before work starts: ask where replacement stone will come from if any pieces cannot be reused, and ask how the crew will control silica dust during mortar removal, since that work involves a regulated workplace hazard. Ask what the quote includes for disposal of old material.

If your Greely property is individually designated under the Ontario Heritage Act or sits within a heritage conservation district, the rules change before any work begins: check your district's heritage conservation district plan or your designation by-law first, and if you are unsure what applies, the City's heritage planning staff can tell you what applies.