How Sustainable is Timber Really?

Dear Richard

Roy Wakeman of The Performance Window Group (The Glazine, 20th May) claims that 'by not using Upvc to replace timber windows you can help grow another tree'.

But back in the real world, rapid deforestation is going on across the planet. Whether it is legal or illegal logging, forest fires, or large scale commodity farming or bio-fuel farming makes very little difference.

The effects on local wildlife and native human populations are often catastrophic. The climate suffers. We all suffer as rainforests are devastated. There is nothing eco-friendly or green about it.

Timber is a world wide market and policing is hard. In practice, tracking timber from the forest through the supply chain is a challenge, especially as some deliberately don't publicise the origins, particularly for valuable hardwood. Even when a tree is planted to replace a hardwood tree cut down it will be many years before it contributes to the climate to the same degree. One hardwood sapling is not the equivalent of a mature hardwood that may take hundreds of years to grow. The net effect is a steady reduction in hardwood trees. Is that really what we mean by renewable?

In 1997 Friends of the Earth reported (Seeing the Wood for the Trees - What the UK timber industry doesn't tell you about the World's forests) that about a quarter of timber companies said they had no idea if their timber was from a sustainable source or not.

Bringing this up to date, an article in the spring issue of Timber Windows magazine says the 'UK Timber Trade Federation estimates that around 60% of all softwood imported into the country is certified sustainable.' Put another way, 40% isn't certified sustainable. That's rather a lot!

Some of Roy's statements about PVC-U are misleading. He says 'Upvc uses oil as a main ingredient.' But almost 60% is chlorine, derived from sodium chloride, or table salt! Ethylene is a by-product of oil, but in the future ethylene will come from ethanol, produced by organic sources such as sugar or vegetable oil.

It's great that timber got an A+ rating in the Green Guide - but PVC-U got an A rating too, with an A+ for commercial windows.

Many of us love timber. We are consumers and homeowners too. For some things such as beautiful wood furniture there is no substitute. But should we really be using - wasting - timber for external products such as windows and doors?

We all know from our own experience that timber windows and doors don't last long without significant expenditure of time and effort on regular maintenance to overcome the effects of natural weathering.

In contrast, PVC-U is the ideal material for windows and doors. It's sustainable and PVC-U windows and doors are designed to withstand the weather with minimal maintenance.

Research on behalf of the B.R.E. in 2006 (Scoping study: Service-life estimation of PVC-u windows) showed that the oldest PVC-U windows in the UK were installed more than 35 years ago and show few signs of age. Realistically, although sealed units and hardware may need replacing, the PVC-U frame is likely to be going strong a hundred years from now.

Yours sincerely

Sam Kennedy
Managing Director
Spectus Window Systems