The battle between moisture and structural deterioration has lasted since man first erected a structure, and it will continue. Masonry systems are designed to prevent the intrusion of natural elements like rain, snow, heat, and cold. But any break or defect in that system can compromise the integrity of the structure, allowing moisture, in particular, to invade and cause considerable damage. One of the places moisture intrusion is common is through weakened or damaged mortar.
When water enters brick or concrete, thermal expansion can cause the surface to peel, flake, or release completely. In essence, the excess moisture exerts outward pressure trying to escape, causing a phenomenon called spalling. Over time, large sections of the masonry can crumble and fall off, causing aesthetic problems and leading to structural damage.
This is a particular problem with older homes or buildings built with softer brick and lime-based mortar. When spot tuckpointing uses cement or concrete to replace crumbling mortar, these more modern materials do not allow moisture to escape through evaporation. This trapped moisture will then force its way out through the older, softer brick, causing spalling and cracking.
Water that is allowed to enter through deteriorated mortar can also seep into other structures in a building. The seepage can cause insulation to disintegrate, and interior finishes to become stained or weakened. Over time, excess moisture will affect interior wooden framing, studs, cladding, and other reinforcement materials, leading to structural degradation and even structural failure.
You may have noticed a coating of powdery white material - efflorescence - on exterior brick. It is a sign that excess water is present within the masonry system of the building. As always, excess moisture can lead to severe problems with deterioration.
Masonry materials like brick contain natural salts of calcium chloride and sodium. When moisture is trapped within the masonry system of a building, winter heat will drive this moisture outward. As it soaks into the masonry, the natural salts dissolve. When this water and salt solution reaches the exterior masonry surface, the water evaporates, leaving behind a while crystalline coating of salt.
Add to this the apparent problem of eroded mortar that has weathered away from between bricks. Eroded mortar allows serious water intrusion, but also looks unsightly and worn, detracting from your old building's appearance and charm.
Traditional Tuckpointing to Protect Historic Architecture
Traditional tuckpointing replaces the mortar joints between brick where it has become soft, or the mortar itself is cracked or damaged. The damaged mortar is carefully removed to preserve the surrounding brickwork. Fresh lime-based mortar, similar to the original mortar, is applied in layers. Tuckpointing using the proper materials will ensure the structural integrity, longevity, and value of older buildings made from brick before the 1940s.
Renaissance Development, a leader in historic home renovation and preservation, specializes in the restoration of a historic brick building's mortar joints using traditional methods (tuckpointing) and materials. Contact us to arrange a free site visit and quote for your mortar repair project.