Sunday, 2 May 2010

What is uPVC?

uPVC is the acronym for the chemical formula unplasticised Poly Vinyl Chloride. In the United States it is often referred to simply as 'vinyl' or 'rigid vinyl'. uPVC is a plastic. Like all plastics it is made from petroleum.

uPVC has been around for more than 50 years and because of its strength and durability has become a popular material for certain aspects of construction work. uPVC is not strong enough to support load bearing walls but it is very suitable as a material for making window frames. In the USA and the UK it has become the material of choice for developers because it is easy to work with and it is cheap.

Timber looks great but there are a number of draw backs with using timber in construction:
  • Timber obviously comes from chopping down trees. Even if the timber is from managed forests the tree serves more use to people left standing and being part of an eco-system that provides habitat, absorbs CO2 and gives out O2. In today's environmentally sensitive climate, trees are gaining in intrinsic value and it is only a matter of time before scarcity makes the price of timber so high that it is not practical to use as a material in construction projects.
  • Timber is not ideal for window frames because it needs to be repaired and painted every two years or so. Hot weather dries out the wood and makes it crack. Wet and humid weather makes the wood swell.
  • As a result, a timber frame is 'alive' in the sense that it is subject to fluctuations in size. This places a strain on the glass it holds in place.
  • Timber window frames are less secure than uPVC window frames. 
In contrast, uPVC windows need very little maintenance. They don't shrink and expand in extreme weather conditions. They are easy to install and very easy to clean. For people living in cold climates, uPVC double or triple glazing can reduce annual energy bills by as much as 20%.

The average life expectancy of a uPVC window is between 25 and 30 years.

For these reasons uPVC windows have become an industry standard in several parts of the world. uPVC windows and uPVC in particular is not without its detractors. In the following blog posts I will look further at some of the key issues surrounding the controversy of using uPVC as a construction material.