Finding an Ottawa mason who repoints with lime mortar?

To find a mason who works with lime mortar, say upfront, in your request, that you want lime-based mortar and ask each respondent to describe their experience with it specifically.

When you speak with a mason, a few things are worth asking directly:

• What lime-mortar mixes have they used, and on what kind of jobs?
• Can they show past work or references from lime-mortar repointing?
• How do they match mortar colour and joint profile to the existing wall?
• How do they cut out the old joints, and how will they control silica dust on site?
• What does the written quote specify about mortar type, colour match and joint profile?

On the mortar itself: the Ontario Building Code (9.20.3.1) requires mortar to conform to CSA A179 and that lime used in mortar be hydrated. The Code sets no rule requiring lime mortar, matching old mortar, or using a mortar softer than the brick. The push toward lime-rich mortar for historic walls comes from heritage district plans. The Centretown and Minto Park plan, for example, states that "lime-based mortar should be used when repointing historic brick and masonry as cement mortar prevents moisture from escaping through the mortar and causes brick damage," and that "using a mason experienced in lime-based mortar is encouraged." The Wilbrod/Laurier and Daly Avenue plans make the same point about matching the original in composition.

Because Brick and Stone Mason (401A) is a non-compulsory trade in Ontario, you cannot look a mason up on the Skilled Trades Ontario public register. Ask instead about their training, how many lime-mortar jobs they have done, and whether they have worked on older Ottawa brick. Get the mortar specification, joint profile and colour match written into the quote before any work starts.

When you send a request, mention that lime mortar is a requirement; masons listed in the Ottawa Construction Network directory reply by email if they take on that work.

If the house is designated under the Ontario Heritage Act or sits within a heritage conservation district, the starting point is your district's heritage conservation district plan or your designation by-law, then a direct message to the City's heritage staff to confirm what approvals the work needs before a mason is booked.