Masonry Joint Repair
What are Masonry Mortar Joints?
Masonry mortar joints are the first line of defense from moisture penetration. Depending on the type of construction, mass masonry wall versus cavity wall, the exterior brick/stone and mortar may be the only protection from damaging water intrusion. Regardless, regular inspections and maintenance of your exterior masonry is good business, as is selection of the right repair contractor. Far too many buildings have suffered irrepairable damage from the use of inappropriate repointing materials and equipment.
Masonry walls, brick, limestone, etc., are not permanent structures, nor maintenance free, and fail for a variety of reasons. Moisture intrusion into a masonry wall can result in freeze/thaw damage to the masonry, corrosion of achorage systems, interior water damage, and potentially mold.
The process for weatherproofing masonry includes the repair of defective mortar joints between the masonry units. This process is commonly referred to as tuckpointing but more accurately repointing, where the defective mortar is partially removed to make room for the new mortar that is tooled to a weathertight condition.
As with any repair process the preparation of the surface, in this case, the mortar joint, is crucial to the longevity of the repair. The mortar between the masonry units is most often removed by the use of grinding wheels designed specifically for mortar removal. These tools should be used by a person trained and experienced to avoid damaging adjacent masonry units. The proper depth of removal is usually considered at least twice the width of the joint. After the mortar joints have been cut, these should be cleaned all of dust and debris, prior to installing the new mortar.
The new mortar material should be carefully selected, and possibly even tested for compatibility with the original mortar and masonry units. Samples should be installed, cleaned, and allowed to dry for proper color selection.
Repointing and selective repointing of masonry structures is the primary scope of most masonry repair and restoration projects. At Mid-Continental Restoration we take great pride in our training programs that teach not only the how, but also the why of all restoration techniques, including the art of repointing masonry.
In conclusion, masonry walls need maintenance, repointing/tuckpointing should be part of that maintenance, and contractor selection is an important part of a successful project.