It is extremely important to ensure there is a proper application of control joints when constructing new brick masonry. However, control joints are often not properly planned because builders mistakenly think this responsibility falls on the structural engineer. At times, the building professional may have delegated all parts of the design plan to the contractor. The proper approach to control joints is brick cladding. Yet there are various types of control joint issues to watch out for:
A brick veneer control joint is basically a continuous gap within the cladding system. The purpose of this kind of gap is to allow the expansion and contraction of the adjacent panels. Some building experts call this an “expansion joint”. Generally, builders can expect most of the movement around the joint to happen within 18 months of the original construction. The future movement will continue once changes occur in the façade temperature and as moisture appears in cycles.
The architect is usually responsible for providing the non-structural expansion and control joints that protect non-structural building elements. As for the structural engineer, they are responsible for designing structural expansion joints to protect the building from settling, live- and dead-loading of the building, and even earthquakes.
The most recognizable symptom of faulty control joint design is when you have extensive vertical cracks in the veneer of the bricks. Sometimes, you might notice a crumbling in the veneer of an outside corner which is another symptom to watch out for. If the veneer expands, this can sometimes force the brick veneer to push away from the wall and warp or bend outward in a highly visible way. The movement of a brick’s veneer can be greatest around the top corners. Also, faulty control joints near the foundation of the building can create shifting of the lower brick courses and even help to create cracks in the foundation’s corners.
Damaging movement with the initial control join configuration usually will happen within the first 18 months of a home or building’s construction completion. The diagnosis is relatively easy to accomplish. However, the repair of this situation can be expensive and requires some special care. In this process, moisture levels need to be accurately assessed to prevent further damage. There are several factors to be considered in addressing this type of damage. Again, a firm or specialist licensed to inspect these situations should be consulted in this process. Using a licensed specialist will be time and money well spent in the long run. When locating the right consultant or inspection group to assess these situations, it is advisable to find someone with an extensive background in building envelope failure or investigations and repair strategies. You should also consider selecting a group that is well-versed in new construction design and commissioning.