Thru-Wall Flashing, the Hidden Gem of Waterproofing
Waterproofing with Thru-Wall Flashings
Buildings constructed in the post 1970 era rarely rely solely on the exterior cladding for protection from air and water penetration. In these cases, the brick, stone, metal, etc., visible on the exterior are primarily decorative cladding that protects the ultraviolet sensitive air and waterproofing systems contained in the wall cavity behind. These flashings are strategically placed throughout the exterior façade to manage waterflow but are most common above window and door openings as well as lower roof levels.
Far too often an important part of the waterproofing system, namely the thru-wall flashing, is either defective, overlooked entirely, or not designed and installed properly. The sole purpose of thru-wall flashing is to divert moisture back to the exterior of the building. When this fails moisture ends up inside the building.
How are Thru-Wall Flashings Repaired?
The repair or installation of thru-wall flashings nearly always requires removing portions of the cladding material to access the cavity. The masonry above is shored in place while the repairs are completed, and it’s not uncommon for window lintels to be replaced during this process. The proper installation of end dams, and termination bars will ultimately determine the success or failure of the repair.