A residential building’s roof is its first line of defense against whatever the skies throw at it. Left untreated, roof problems can proliferate and cause thousands of dollars in damages to residents’ property, as well as the building itself. When it comes to the literal roof over your head, “out-of-sight, out-of-mind” is definitely not the attitude to take—particularly once winter's bad weather has passed and left potential damage in its wake.
What's Up There?
In New York City, most residential roofs are flat roofs, which generally have little to no slope. Flat roofs represent the most efficient use of urban space, offer architectural freedom and energy savings, and control of the downflow of water into the drainage system. They are considered an economical alternative to the sloped roofs found on other residential structures, and are designed to protect the building from moisture and other exterior elements, and to support the mechanical and electrical equipment that serves the building.
Early flat roofs were designed using tar as a waterproof coating, but the uneven surface often created problems with rainwater and snow-melt ponding in low spots and causing leaks and other damage. Modern flat roofs use a continuous membrane covering which can better resist pools of standing water. These membranes are applied as a continuous sheet by utilizing sealants and adhesives that allow for bonding multiple sheets and dealing with structures—pipes, skylights, exhaust vents, and so forth—that penetrate the roof surface and can become entry points for water.
Roofing is pretty simple, says Wayne Bellet of Manhattan-based Bellet Construction Co. The roof consists of a membrane, into which are placed protrusions like pipes, parapets and drain openings. Roofs are vulnerable, he says, because they are exposed 365 days a year to weather—sunlight and ultraviolet rays, and most of all, moisture.
“There is one more ingredient that threatens the solvency of a roof, that being foot traffic. And foot traffic can be intentional vandalism, like people trying to deliberately harm the roof and then you have what I call accidental vandalism, which is, for example, women who wear their stiletto high heels that don't realize they are causing harm to the roof. People don't realize when they bring their terrace chairs and tables that when they sit on them, they're transferring 200 pounds of pressure into a softened asphaltic material that could cause a leak.”