CASE STUDY #3
New products constantly flood the construction industry. Some promise and deliver real positive advantages, while others leave questions as to their real advantages over possible new disadvantages. Moisture management has been a real concern in all phases of construction for centuries. It is generally agreed that moisture must be dealt with in a way that will protect a structure for life. Properly designed through-wall flashings are the widely accepted answer to moisture migration in typical cavity wall construction. Proper attention should be given to the location of these flashings, along with the type of materials used.
For hundreds of years, copper has been used in those critical areas where moisture management is a concern. It could be said that copper flashings have stood the test of time and continue to be the most reliable flashing product to assure lasting protection. When choosing a flashing material, longevity should be your main objective.
Case and Point
About 50 years ago, a small U.S. Post Office was built in Hampton, N.H. The structure was a basic brick exterior with a block interior wall. This structure served as a post office for about 22 years and then was sold to a local bank. Due to the location of the building and local zoning regulations, the size and general appearance of the building could not be altered. Thus, the new owners could make only minor changes to the exterior of the structure. Windows and doors were replaced in favor of new, more energy-efficient models, but the approximate size and location remained unchanged.
Twenty-eight years later, the bank relocated, and the building was sold to a national donut chain. Once again, minor changes were undertaken to change the doors and windows, but the location remained the same, as did the structure — and the flashing. The flashing over the windows and door is the original copper fabric flashing that was installed about 50 years prior (see image). The longevity of copper has proven itself through the many lives of this small structure in New Hampshire, and will continue to protect against moisture problems through the years and changes ahead.
This story is not unique. Walk down the streets of a large city, such as Boston or New York, and you’ll see extensive use of copper in most of the oldest structures in the city. Will peel-and-stick and PVC flashings be around 50 years from now? New products constantly flood the construction market. Choose wisely.
Case Studies: Flashing
- 43It has become increasingly difficult to cut through the clutter when choosing products for flashing and drainage systems in cavity wall construction. Manufacturers now are trying constantly to reinvent the wheel with new and improved materials, driven by the notion of holding the only acceptable product in a specification.