As mortar joints on stone and brick buildings age, they can begin to crack and crumble, due to salt deposits, pollution, weathering and water damage. Re-pointing masonry bricks will help restore the appearance and functionality of your mortar joints – and your property as a whole. However, there are a few things that you must keep in mind, when you are looking for the right masonry company to handle the job.
One of the things about re-pointing masonry bricks that makes it complex is that the mortar used in the restoration process must be identical to the mortar that was used when the building was originally constructed. This is because mortar not only serves as an adhesive to keep your bricks and stones in place. It is also the material that cushions the structure as it settles into its foundation and as it expands and contracts with the heat and cold. Mortar joints are also responsible for carrying water away from masonry units to protect them from water damage, such as salt deposits and sub-surface freezing, which can lead to cracking, flaking, loosening and displacement.
- The mortar used for re-pointing masonry bricks must be softer than the bricks that it will be supporting. This is because, as a cushioning material, mortar must be flexible and have a little bit of give, in order to accommodate the shifting, expanding and contracting of the building. Mortar that is too dense or un-giving will result in joint rigidity and, ultimately, the destruction of the bricks that it is supposed to be supporting.
- The mortar used for re-pointing masonry bricks must also be equally as water permeable as the original mortar (and even more water permeable than the masonry units themselves), in order to ensure proper drainage and protection. The water permeability of a substance refers to its ability to allow water to flow over or through it. In the case of masonry, it refers to the ability of mortar to draw water away from bricks or stones and then allow it to be evaporated into the atmosphere. This is why mortar must be more water permeable than the bricks or stones themselves.
Keeping Up Appearances
In addition to performance, new mortar used for re-pointing masonry bricks must be matched to the original mortar because different combinations of mortar ingredients result in different colors. Un-matching mortar joints are unsightly, and they are also the tell-tale signs of substandard work.
This is why it is important to work with a masonry contractor who is well-versed in the restoration process and well connected with industry experts. Acid testing and scientific analyses can be utilized to determine the exact combination of ingredients that were used to create the mortar that was used to construct your historical building. And, with that information, an exact recipe can be formulated to recreate the color and consistency of your original mortar – even if it was made using horse hair.
- Mortar prior to the mid 1850’s was made from a variety of materials, including lime putty, slaked lime, animal hair, crushed seashells, clay, brick dust and sand.
- Between 1873 and 1930 mortar consisted primarily of sand and lime, pure lime and Portland cement and sand
- Buildings constructed after 1930 were built using mortar that was equal parts lime and Portland cement
Financing the Restoring of Historical Buildings
Owning an historical home or other valued masonry structure can be quite costly, if you don’t know the right channels to navigate in your pursuit to restore the property to its former glory. Before you begin your restoration project, do a little bit of research and track the history of your property. See if you can unearth any historically significant owners or events that can be connected to it. Then write a letter to your local historical society to see if you might be entitled to any regional or state funds that have been set aside for historical restorations. You may also be able to submit a petition to the local business guild for donations to offset the costs of your restoration. The important thing to remember is to investigate your resources before moving forward.
If your residential or commercial property is in need of restoration, contact a local masonry contractor, and make sure they know the importance of matching mortar and masonry units.