Let’s get straight to the point. Repointing (pointing, pointing up) is the process of renewing the pointing, which is the external part of mortar joints, in masonry construction. Over time, different weather may cause voids in the joints between bricks, allowing the unwanted entrance of water. Significant damage may be caused by water, frost and salt dissolution. The repointing process will help you take care of that problem.
To start the repointing process, you need to remove damaged pointing as deep as the width of the joint, or to the point where you can reach the sound mortar, or even a little deeper, depending on the situation. If it goes deeper than 2-1/2”, fill it in several passes, so that the mortar will cure for at least 24 hours. You want to make sure the joint is as rectangular as possible, because the new mortar must have ample opportunity to bond with the masonry unit. You may keep the sound mortar on a building during the repointing process, thought many professionals do remove it as a common practice.
Make sure you don’t damage any bricks while you remove old mortar between the joints. If it’s an old building with rather soft materials like under-fired bricks or something similar, try to remove mortar by hand only. That way you won’t cause any extra damage to the building. Professionals usually do it by hand or with small power chisels. On buildings with hard Portland cement it’s more efficient to use a grinder or power circular masonry blade. These tools will help you take care of the damage and keep masonry units from any extra destruction.
There are some problems you may face if you don’t hire a certified masonry professional. For example, poorly done repointing may raise the level of the mortar joint right above the face of the brick. It will cause the mortar edge to feather. You don’t want to deal with this kind of problem, because it will cause extra erosion problems. The corner of the brick may be damaged as well if mortar rises above the level of the face of the brick. It’s different in each case depending on the nature of the mortar.
As you already know from our articles about repointing, the type of mortar used for repointing must be the same as the type originally used, including color, texture, compressive strength, permeability, and thermal expansion coefficient. Let’s say soft lime mortar was used during the original construction process. It’s obvious that the mortar that you should use for repointing is one that has a large amount of lime in it. But what if you use Portland cement instead? The answer is quite simple – it will cause damage because of the physical incompatibilities.
The repointing process may look easy from the first sight, but if you’ve been doing it long enough and know all ins and outs, you know how complicated it may get if you use wrong material on the building you are working with. When you look for local masonry companies, make sure you hire a professional like BR Masonry that knows everything about the repointing process from start to finish, otherwise you risk getting even more damage to your building. Contact us to get a free estimate today!