Repointing Brick & Stonework
A small percentage of my workload typically entails repointing Heritage stone and brickwork —most notably, brick chimneys, such as these two from the 1960's era.
Whether I am repointing brick or stone walls, an air chisel with a Spike bit makes quick work of recessing mortar joints, along with a 15.8-litre Air Compressor which is relatively good at keeping up with my pace.
I recess the mortar joints to a 1” depth, as this is ample space for the new mortar to form a strong bond. I then use an Air Blow Gun to remove all dust and debris, because it makes for a clean gap for the fresh mortar to adhere too.
This method is a great alternative to using grinders, hammer drills, or simply a hammer and chisel, as you reduce the risk of accidentally cutting into the face of the surrounding bricks or stones with a Grinder, and apply much less force then you would with a Hammer Drill, which could cause breakage to the masonry. Not to mention, the Air Chisel is incredibly lightweight and just powerful enough to rip through the existing cement.
In the case of this brick chimney where spalling has occurred and the mortar joints crumbled through and through, it became necessary to remove the bricks and rebuild the chimney until I felt little to no movement when applying pressure to them.
When you are faced with a similar situation, it’s important to acknowledge that simply recessing the existing mortar joints by an inch or so and not dealing with the rest of the frail mortar, is like putting a Band-Aid on a gaping wound. You are just inviting moisture into the crevasses created by the failing cement and allowing further havoc to take place during the freeze/thaw cycles. This also generates a habitable environment for vegetation, such as moss, to grow and damage the masonry structure.
If you're a Homeowner in need of Custom Design & Stonework, Heritage Restoration, Chimney Repair, Concrete Forming & Pouring, or any other Masonry needs, please Contact Us today to receive a no-obligation quote.
- Sean Lennox, LennoxMasonry.com, Victoria BC, Canada