Brick re-pointing is the process of removing cracked, damaged and crumbling mortar from the joints of masonry structures and replacing it. The procedure is vital to the preservation of both historical and contemporary buildings.
One of the main causes of mortar breakdown is salt deposits, which are generally caused by two things.
- Salt is sometimes naturally present in the building materials themselves, and it can be forced to the surface of the mortar and masonry units by water (rain, power washing, sleet, etc.) or rising damp from the ground.
- Salt can be also absorbed by mortar and masonry units from the groundwater that gathers or flows at the foundation of a building.
Salt deposits look like white stains or bleached out areas, where the masonry units are unusually lighter than the rest of the bricks and stones that are surrounding them. When salt deposits gather beneath the surface of a masonry construction, they expand, and the pressure of the expansion causes the mortar and masonry units to crack, crumble and erode.
A Word of Advice
It is much easier and less expensive to replace mortar through brick re-pointing than it is to replace masonry units. So if you have noticed any salt deposits on your home or business property, you should take immediate action and contact a masonry contractor for advice. Once salt deposits form, they will only continue to grow and cause even greater and more expensive damages.
Whenever brick re-pointing is performed, it is essential that the new mortar being used is identical to the mortar that was originally utilized to construct the building. This is not only important because you want the color of the re-pointed joints to match with the rest of the building but also because you need the new mortar to function in the same capacity as the original setting mix. Mortar is so much more than the “glue” that holds a building together. It is the cushion that accommodates the expansion, contraction and settling of your masonry home. And it is the component that draws moisture away from your bricks and stones to prevent water damage, staining and erosion.
- Historical homes built prior to the 1850’s were constructed using a combination of lime, lime putty, local sand, animal hair, crushed seashells, clay and brick dust. Later buildings were constructed using mortar that consisted of pure lime, lime and sand, and Portland cement and sand.
Masonry contractors and preservation experts can take samples of your original mortar and analyze it to determine which components were used to create it; they can even determine the ratios of the ingredients used.
The Brick Re-Pointing Process
Once the recipe for your new mortar has been discovered, a masonry contractor will begin your re-pointing project by removing your old mortar. Mortar removal is performed using a combination of hand chisels and mechanical grinders. It is a job that must be done very carefully, in order to avoid causing any unnecessary damage to the bricks and stones of your home. To guarantee that you will receive quality results, you should ask your masonry contractor how they will be removing your old mortar and request to see pictures of their finished works.
Once the old mortar is removed, the joints of the masonry units are washed out with water and left moist to prevent bricks and stones from absorbing the water in the new mortar. This would weaken the setting mix and lead to inferior results. Then the new mortar is applied in quarter-inch layers, until the joints are completely filled again and your home is restored.
Some contractors have been known to use saws, when removing old mortar, which can lead to unnaturally squared joints and damage to bricks and stones. Do not take anyone’s word about their skill level, without proof. And do not settle for a contractor simply because they have offered you the lowest estimate. Protect your home and your pocketbook and request references along with photographs, before entering into any labor agreement.
If the mortar of your masonry home or business property is beginning to crack and crumble, contact a masonry contractor or preservation specialist in your area.