Masonry Magazine June 2004 Page. 18
Restoration Techniques
Repointing: How to Properly Restore Old Buildings
By Mario Cantin
Invisible Tuckpointing Ltd.
So much has happened in the last 100 years: the automobile, electricity, the airplane, two world wars, television, space exploration, computers and a lot more. Consequently, we live faster - and we build faster as well.
Unfortunately, unless you are over 90 years old, masons have never been exposed to how our predecessors used to build, due to the advent of the modern cavity wall and cement-based mortars, which have replaced traditional bonding methods and lime-based mortars. This only becomes problematic when we attempt to repair older structures. It is especially made evident when repointing is attempted on older buildings using the wrong mortar mix -and the wrong joint finishing style to boot.
Just as we do a professional job when building new masonry projects, we can achieve the same degree of quality through acquired knowledge when tackling older structures.
Definition of the Terms
So what do you need to know? Let's start with this basic question: What is repointing? Have you ever wondered what the difference is between the words "pointing," "jointing," "repointing" and "tuckpointing"? Although there is no longer a distinction, even among engineers, between the terms, over a century ago the difference was clear.
"Jointing" referred to the process of finishing the joint as the brickwork was erected. Jointing is what all bricklayers do today.
"Pointing" denoted the placement and careful tooling of a mortar joint between bricks or stones. In contrast to jointing, pointing was the process of raking back the mortar joint a few days after the completion of the brickwork and was usually done by a different crew that was skilled in delivering a high-quality, consistent decorative finish to the joint. Also, jointing was performed at the rear and sides of a building, with only the front façade being pointed.
"Repointing" referred to replacing a mortar joint when it had failed, on average about once a century. This was typically the type of restoration work completed on older mortar.
"Tuckpointing" (Figure 1) is an interesting one, which will need further explanation.
Figure 1: A well-preserved example of tuckpointing performed circa 1850.