Loose chimney brick and open joints repaired in Bithlo

Why head joints need hand work

The short vertical joints between bricks are called head joints. Brick industry guidance warns that a grinder cannot remove the full depth of mortar from them without damaging the adjacent brick, so the remaining mortar has to come out with a chisel.

It is slower, and it is the difference between a clean repair and chipped brick corners along every joint. We budget the time for it in the estimate instead of rushing the step that shows the most.

Replacement brick that suits the old

Replacement brick must match the existing brick's color, texture and size, and also its physical properties. A brick that looks right but behaves differently can stand out as it weathers or strain the masonry around it.

Locating a match can take real effort, the note adds, and we do that work before the repair. The estimate shows the brick we propose and how close we expect it to be. When a close match is not available, we tell you before ordering and discuss where the less visible faces of the chimney might hide the difference.

Finding brick that matches

Brick varies by maker, era and batch, and Technical Note 46 notes that locating matching brick may take considerable effort. Size matters as much as color, since a unit that is a little too long or tall changes every joint around it.

We compare candidates against the existing brick in daylight and tell you how close each one comes. Where sound bricks from the repair area can be cleaned and reused, they often give the closest match of all. The estimate says whether the proposed brick is new, reclaimed or salvaged from the chimney itself.

Questions worth asking before you approve masonry work

A sound masonry proposal should answer each of these clearly. If one gets a vague answer, ask again, since each affects how the repair performs and what it includes.

• What is causing the damage, and is it fixed by this repair?
• Where exactly does the repair area start and stop?
• Which mortar type is proposed, and why?
• How close will the brick and mortar match be?
• What happens if more damage turns up?
• Which separate repairs, if any, are recommended?