Repointing: How to Buy It Once Instead of Every Few Years
Two specifications decide whether joint repair lasts thirty years or three: the mortar mix and the raking depth. Neither is visible at handover.
Joint repair is a large, disruptive, one-time job when it is done right, and a recurring frustration when it is not. The difference comes down to two things you cannot see once the work is finished, which is exactly why they need to be agreed before it starts.
01The terms, quickly, so they stop confusing the quote
Repointing is raking out failed mortar and replacing it. Tuckpointing is strictly a decorative finishing technique using two mortar colours. In everyday use both usually mean the first one.
It rarely matters — but agree which is being done, because a quote for one against an expectation of the other starts the job badly.
02Specification one: mortar softer than the brick
Mortar is meant to be the sacrificial part of the assembly. Softer than the brick means movement and moisture damage the joint, which is replaceable. A modern high-strength mix in older soft brick reverses that and the brick face spalls instead.
That damage is permanent — you cannot repoint a spalled brick face back. On an older chimney the wrong mix does more harm across a decade than leaving the failing joints alone would have.
03Specification two: raking depth
Joints have to be cut back to sound mortar so the new material has something to key into. A surface smear over deteriorated mortar looks identical on the day of handover and detaches within a season or two.
Ask what depth is being raked before work starts. It is the question that most reliably separates a thirty-year repair from a three-year one, and it costs nothing to ask.
04The prerequisite that makes both moot
If water is still entering — a failed crown, bad flashing — or the structure is still moving, the new mortar goes into a joint that is under active attack. It will fail regardless of how well it was specified.
So repointing is the last item in the sequence. Crown and flashing first, movement resolved first, joints last.
Agree the mortar is softer than the masonry, agree the raking depth, and confirm the water and movement causes are handled first. Three questions before the job starts, and they decide whether you ever buy it again.
Every recommendation here starts from one place: a graded, photographed chimney inspection done to one standard, with a paper trail you keep.
The Prime Chimney Services Team
This article was written and reviewed by the CSIA-certified crew at Prime Chimney Services. Every recommendation reflects NFPA 211 and CSIA trade standards and the same documented, photographed approach we hold every job to.
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