Will Vinyl Windows Last?
They don’t have the track record of wood windows, but chosen and installed with care, modern vinyl products can compete.
Synopsis: It is easy to see why vinyl windows now make up about two-thirds of all window sales in the United States: They are less expensive than wood, they are impervious to moisture, they don’t rot, and they don’t need to be painted. In this article, contributing editor Martin Holladay addresses the important issue of how vinyl windows will look and perform when today’s homes become historic. He states that vinyl windows are better made than they were 30 years ago, attributing this in part to a certification program launched in 1985 by the American Architectural Manufacturers Association. In order to become certified, windows must pass tests for impact resistance, dimensional stability, heat resistance, weight tolerance, and colorfastness. Still, a window is only as good as its installation and maintenance, so Holladay provides a list of tips to help ensure that these windows perform as they are designed to do. Finally, Holladay explores the three phases of vinyl-window construction—formulation, extrusion, and fabrication—and takes a look at vinyl-clad windows.
In many American neighborhoods, houses that are more than 100 years old still have their original double hung wood windows. Although long-lived, wood windows have some drawbacks: They need to be repainted regularly (a complicated chore, because old layers of paint usually contain lead), they have energy wasting single glazing, and they are difficult to seal against air leaks.
Because of these drawbacks, many homeowners have abandoned their historic windows in favor of double-glazed vinyl replacement windows. The advantages of vinyl windows are fairly appealing: They are less expensive than wood, don’t absorb moisture, don’t rot, and don’t need to be repainted. These advantages are largely responsible for vinyl windows’ share of the current U.S. window market, which has grown from 24% in 1990 to about 66% in 2010.
Vinyl windows do, however, have drawbacks. They are difficult to repair; they are available in a limited number of colors that can’t be repainted as styles change; and according to Consumer Reports tests, the average vinyl window leaks more air than the average fiberglass or wood window.
With so many houses now being fitted with vinyl windows, a burning question is beginning to surface: How will these modern vinyl windows look and perform when today’s homes become historic?
Manufacturers’ warranties are driven by marketing rather than logic, and window experts are cautious with their predictions. The relatively short 40-year history of vinyl windows provides only limited data, and our need for long-lived windows must be balanced against practical considerations, including the ever-changing demands of consumers, building codes, and energy guidelines. If vinyl windows have been specified for a project, the best option is to choose a top-quality model and install it impeccably.
Better windows through stricter guidelines
Ever since vinyl windows were developed in the 1970s, they have been subject to a certain amount of derision. According to Gene Summy, a window expert and president of TLS Laboratories in Laguna Niguel, Calif., much of this scorn is unmerited. “When vinyl windows first came out, a lot of the so called experts said that vinyl was nothing but a liquid in a solid state, and that they were destined to crack and fall apart,” Summy recalls. “But I have not seen any of those predictions become a reality. As long as the windows aren’t abused or misused issues that would affect any window they will provide a long, useful life.”
Vinyl windows have been proving skeptics wrong due in part to a window-certification program launched by the American Architectural Manufacturers Association (AAMA) in 1985. Since its inception, the certification program also has been embraced by almost all U.S. vinyl-window manufacturers. The program has been endorsed by the International Residential Code, which now requires vinyl windows to be certified.
To obtain AAMA certification, a vinyl window must be made from vinyl extrusions that have survived a battery of tests performed by an accredited third-party laboratory. Tests include impact resistance, dimensional stability, heat resistance, weight tolerance, and color fastness. The extrusion samples also must survive outdoor-weathering tests for at least one but in most cases two years. Assembled windows are also tested for structural performance under wind loading, as well as for resistance to air leakage, water penetration, and forced entry.
For more photos and details on the longevity of vinyl windows, click the View PDF button below.