It’s back to school time and facility managers are busily preparing their buildings’ classrooms, gymnasiums, cafeterias and other interior spaces for the rush of students returning from summer break. Obviously, this is an important task, but how much consideration is given to ensuring that the building’s exterior façade is also ready?
Maintaining the exteriors of educational facilities is just as important as maintaining their interiors for the safety and comfort of the students, faculty and staff.
There are several areas of a building’s exterior that can deteriorate and allow water penetration. Over time, this can cause interior damage, as well as other structural issues. Routinely inspecting and making repairs to those areas in a timely fashion will help to ensure a safe and attractive learning environment for everyone and reduce costly repairs down the line.
Brick and Mortar Joints
A building’s brick façade is built from the ground up. One story is built, then a steel lintel is installed for the next floor up. Sometimes those lintels don’t get installed properly and are installed right on top of the brick. Therefore, when the next floor is built up, it doesn’t allow for the expansion and drainage that is required, which ultimately causes the brick to self-destruct and spall. If this condition is not attended to in time, the entire brick wall may have to be repaired.
The flashing systems are another important element of a building’s exterior to consider. The mindset of the flashing system installer is generally not on the system as a barrier. In many cases involving masonry walls, when the brick is pulled out, it appears that not a lot of attention was given to the actual sealing or waterproofing of the backup substrate to the flashing. It may be absent or not installed properly. If this problem exists, the flashing system may have to be redone, which involves removing several courses of brick above the steel lintel so new flashing and waterproofing can be installed. This work will help ensure any water that enters the masonry will be allowed to escape in the location of the flashing and away from the building.
Caulking and Sealants
A large and important part of any building’s exterior are its sealants. When the sealants on a building’s exterior appear cracked, spongy or chalky it indicates they are probably beyond their life expectancy. With most urethane sealants, the life expectancy is generally in the five- to 10-year range. Silicone sealants will last longer than urethane sealants but will still need attention after about the 10-year mark.
Cleaning and Sealing
There are a lot of ways to clean different façade surfaces. Careful consideration must be given to which type of processes are used to clean the various façades. Some processes can be very damaging to the substrate. For example, sandblasting is a quick way of cleaning a surface but it can be damaging to a lot of surfaces. There are also a lot of different cleaning compounds—some are stronger, some are milder. It is important to hire a professional architect, engineer and/or specialty contractor who has experience with proper façade cleaning to ensure that damage isn’t done to the building. Cleaning a façade is done primarily for aesthetics, however it is also done to clean algae, fungi and carbons that attach to buildings and can advance the deterioration of the structure.
Although there are many different types of masonry construction, there are also different types of sealers to protect them. A Rilem Tube Test can be used to determine the effectiveness of a building’s existing water repellency. With this test, a Rilem tube is sealed to the building over the mortar joint of the masonry unit and filled with water to simulate an 80-mph, wind-driven rain to the surface. The rate that the water is absorbed into the wall is then calculated. The faster the water disappears into the mortar joint, the more a sealer may be needed. Working with an architect, engineer or experienced specialty contractor is recommended to determine existing conditions and the best type of sealer for the building.
In the case of plaza decks, the topping systems, such as a poured concrete slab or pavers over a waterproof membrane, can deteriorate along with the waterproofing below causing the need for complete removal and re-installation. Sometimes the topping systems are in good shape, but the waterproofing is in bad shape; maybe it was never detailed properly or it could be a number of other malfunctions. If water is getting into the building from the plaza, the plaza deck should be fixed.
In the instance that repairs cannot wait until the school year is complete, be sure to find a specialty contractor that has experience with minimizing construction-related noises and can keep intrusions to a minimum so as to not disrupt the learning environment while the repairs are underway.