Fences made from a type of plastic known as polyvinylchloride (PVC) have increased tremendously in popularity since they were first introduced in the 1980's. Many people prefer fences made of this material due to its low maintenance, durability, low long-term cost, and potential for aesthetic appeal.
Although several environmental organizations have issued warnings concerning health risks with this material, its growth rate for fence usage is among the highest in the industry.
Composition of Vinyl Fences
Two production processes may be utilized for PVC fences; mono-extrusion and co-extrusion. Mono-extrusion inserts ultraviolet (UV) protection, usually titanium dioxide, in the product before shaping it, resulting in a material that is homogeneous throughout the product. Fences made with co-extrusion feature an outer layer of PVC treated for UV. Mono-extrusion is the more expensive of the two processes.
Although UV treatment raises the cost of the product, many find it essential as the material cannot withstand exposure to strong sunlight without it. The manufacturing process also includes impact inhibitors which increase the flexibility of the product and thus decrease its vulnerability to strong pressure. Despite a flimsier appearance, PVC is actually a stronger material than wood with about five times the strength and four times the flexibility of wood.
PVC also has an advantage over metal in that a scratch on the surface of PVC does not incur a progressive problem like rust. Wood still has some advantages such as higher resistance to heat and newer methods include wood flour into the production process. Some manufacturers also fill the a hollow space within the PVC fence components with wood.
Many experts recommend comparing fences by the thickness of their components including posts and rails when deciding to buy a PVC fence.
Vinyl Fence Design
The most popular designs for PVC fences include privacy, picket, and shadowbox.
Privacy vinyl fences present solid walls and do not permit any visibility. Many people choose this design when privacy is an essential consideration.
Picket vinyl fences allow visual permeability but many find them aesthetically more attractive than other types. These fences are usually used as a landscaping feature.
Shadowbox vinyl fences utilize alternating boards placed forward and backward of supporting rails. They do not permit a high amount of visibility, but they do encourage air circulation and some variation in their face creates some more visual interest than privacy fences. Designs for fence tops have also advanced with more decorative finials and caps.
Maintenance of Vinyl PVC Fences
PVC requires little maintenance, usually simply soap and water sprayed from a hose. Even a fairly hard rainfall may adequately clean it. It naturally resists fire due to its high chlorine content and also resists water and paint making it attractive for consumers concerned about graffiti. Many manufacturers also offer lifetime guarantees. One concern that many experts voice is harsh cold which may cause frequent expansion and contraction, resulting in cracks.
Vinyl Fence Installation
Initial installation costs may be higher than wood, but the lack of a need for heavy maintenance reduces long-term costs by about two thirds in comparison to wood. However fences should be installed with concrete foundations and metal fasteners to ensure installation of a solid fence.
Using other types of foundations and fasteners may result in sagging, especially for fences installed on soft ground. Installation generally requires two people who can install the fence in less than a week.
Environmental Debate Over PVC Fences
Many environmental groups decry the usage of PVC claiming that it presents severe environmental and health risks; however, many manufacturers insist that the product is safe. Research has shown that subjecting PVC to high temperatures releases hydrogen chloride gas and dioxin, poisonous gases that endanger people and animals, as well as pollute the air.
Some fire departments actively discourage the usage of PVC to protect their firefighters. PVC has also been linked to respiratory problems and some types of cancer. Many groups opine that the material can leach harmful chemicals polluting groundwater. Finally, although this material is recyclable it has a very low rate of recycling.