Polyvinyl chloride (PVC), commonly known as vinyl, is a popular and useful plastic. One of the most common applications for vinyl is in windows, where the material offers a number of advantages and disadvantages.
A few facts about vinyl and vinyl windows:
Vinyl is the second most produced plastic by volume worldwide (after polyethylene), and the most produced plastic for building and construction products.
The first vinyl windows were manufactured in 1954 in Germany in response to post-war wood shortages and the rising price of aluminum.
Thermal Industries introduced the first vinyl windows in the United States in 1964. They became popular during the energy crisis of the early 1970s when consumers were looking for energy-efficient alternatives.
Today, vinyl windows make up more than half of the market share of residential window sales.
Advantages of vinyl windows:
They offer myriad design options. Vinyl can be molded easily into almost any shape. Custom colors and finishes are available to suit almost any design specifications.
They require relatively little maintenance. They never need to be sanded or painted, and can be cleaned easily with soap and water.
They're energy-efficient. Compared with other window materials, such as wood or aluminum, vinyl windows are great thermal insulators.
They're recyclable. Vinyl, like other thermoplastics, can easily be melted and remolded into new products without losing its chemical characteristics. According to the American Architectural Manufacturing Association, vinyl production is more than 99% efficient, and, in 1997, more than a half-million tons of the plastic were recovered and recycled into other useful products.
Disadvantages of vinyl windows:
They have the tendency to sag due to their flexibility. Their flexibility also limits their size and the weight of the glass they frame.
Many people find them less elegant or natural-looking than wood.
Vinyl window frames can soften, warp, twist and bow if heat builds up within the frame.
They are not particularly strong or rigid.
They have the tendency to discolor over time, especially when subjected to extreme weather conditions.
They are difficult to paint. Most paints will not easily adhere to vinyl, and some primers can weaken the vinyl.
weep holes on the sides or the top of the frame. Weep holes are small holes that allow water to leave the window frame before it accumulates and leaks into the house. Manufactures drill these holes into the bottom side of the frame. Occasionally, installers will inadvertently install the window upside-down so that the weep holes are on the top, making them useless.
alarm holes that permit water penetration. While installing an alarm system, installers will often drill a small hole for the alarm wire at the base of the window frame. In vinyl window frames and other hollow window designs, water may leave the window through this hole and follow the alarm wire into the house. This water penetration can cause serious interior water damage.
separated mitered corners. Mitered corners –- welded junctions where sides meet -– are particularly prone to separating during the stresses of installation if the glass has been removed. Installers occasionally remove the glass from the frame so that it is lighter and can be installed more easily. If such a separation occurs, it becomes likely that water will enter the building and cause damage. Inspectors can roughly measure this gap and demonstrate its danger to clients by inserting a business card into it.
sagging. Unlike wood, which is more rigid, vinyl has the tendency to sag over time. This warping is a cosmetic blemish as well as a potential cause for the window to become inoperable. If the frame sags, operable windows may bind or jam.
In summary, vinyl windows are popular window siding options, but inspectors should be aware that there are a number of defects that are unique vinyl windows.