The chemistry of wood

This video is all about the chemistry of wood - and contains a lot of cutting edge science. The structures in wood that help determine its properties are tiny - it its only recently that technology has developed to the point were we can measure them and work out what they do. The work means chemists, engineers and foresters working together. This video is also available on the firrs DVD.



Here's another short wood science video that mentions cellulose and lignin - this one is from the History Channel.

why wood : what wood

Last week I gave a presentation it the Institute of Materials, Minerals and Mining in London, which was part of their Materials and Design Exchange (MADE). This was intended as an introduction to wood as a material and used some of the videos made for the firrs project. You can download a pdf copy of my presentation, with a few notes on what I said, here.

Is it wood, is it bricks or is it lego?

Time to practice your French with this post. One of the big new things coming over from continental Europe is "massive wood construction". This is an extension of the idea of a traditional log cabin - in which the walls are solid wood - but updated with modern hi-tech manufacturing methods. So instead of irregular round logs you have nice regular building blocks.

This provides very good insulation keeping the heat in and the noise from outside out. It's also greener than conventional fired clay bricks - which require more energy to make and produce more carbon dioxide in the process.

Obviously it requires an awful lot of wood, but the good thing is that cheaper, low quality, wood can be used. As there is so much of it, the force is shared over a bigger area, meaning it doesn't have to be nearly as strong or as stiff as the wood used in a timber frame building.

You might see this type of construction more often in the next few years for buildings like schools and hotels.

The first video is an explanation (in French) of one particular system of massive wood construction (there are others). Notice the computer controlled robotic cutting and drilling machines. Wood manufacturing really is like this in the 21st century.

The second video, which has no sound, shows the same system being used to actually construct a building. Notice how accurately the pieces fit together thanks to the precision manufacturing.

Careers in the timber industry

The UK's multipurpose forests provide environmentally friendly materials for all sorts of things and there are a vast array of different types of job out there.

For more information on jobs visit The Doorway and A Job In.

Deforestation and certification

This video from Greenpeace has a forceful message. It asks the question:

"Why destroy ancient forests for wood and paper, when it can all come from responsibly logged timber?"

Why indeed.

Well one reason this happens is that many people don't really understand how they can choose wood products that are environmentally sustainable - and come from properly managed forests. There is good wood and bad wood and we all need to understand the difference. Check out the certification schemes like FSC and look for the logos. Buying certified wood is a good thing...it encourages people to look after their forests.

The story of a forest ranger

This is another film from the excellent Prelinger Archive. This one was made in 1954 and looks at the job of the forest ranger in the USA. Again, you might recognise parts we used for our own videos.

Notice how the forests are talked about as a resource...but also how emphasis is placed on sustainable forestry and protection of the environment...even back in the 50s! Notice also how they stress the importance of avoiding forest fires. Back then many people smoked and lots of fires were started accidentally. Forest fires are still a big issue...all over the world (the UK included).

Wood for war - wood for peace

Ironically, the fact that we now have so many well managed forests in the UK is down, in part, to two of the most destructive events of the 20th Century: the two world wars.

During the First World War (1914 to 1918) Britain had great difficulty meeting the demands on timber - particularly for coal production and trench warfare. Britain's forests had been on the decline since medieval times and had been put under enormous pressure by the industrial revolution. Timber had been imported in large quantities for hundreds of years, but the war meant this supply was no longer reliable.

In 1919 the Forestry Commission was created and charged with reforesting the country with the help of private foresters. The idea was to improve the productivity of the forests and to create a large reserve of wood that could be called on in times of emergency.

Such a time came only a couple of decades later with the Second World War (1939-1945). During the war, the Commission's forests produced nearly one and a half million cubic meters of wood and nearly ten times more came from private estates.

These were times of great social change too. The 'lumberjills' were the forestry equivalent of the land army girls, but they weren't just felling trees - they were planting too...and the forests have been growing in size ever since.

Over the last 40 years or so the Forestry Commission has included conservation, ecology, recreation and tourism within it's objectives...and that's why we have today's multipurpose forests.

This is a video from the Prelinger Archive that was made during the Second World War looking at the same things from the American perspective. You might recognise parts we used in our videos.

Wood and the environment

Today is "blog action day" so a good time to look at how the forest and timber industries impact on the environment.

Is using wood good or bad for the environment?

Well the answer is that it can be both...at the moment.

OK, environmental issues are complicated so I'm afraid your going to have to concentrate while I try and explain this.

We all use wood products in our daily lives...and so it is very important that everyone understands this: there is good wood and there is bad wood.

Let's start with bad wood. Thankfully most people these days are aware that forests are being destroyed in some areas of the world. Some of this is because of logging for timber and some of it is because land is being cleared for other uses. This is a bad thing...for all sorts of reasons. As well as being the "lungs of the planet" forests provide homes to lots of animals and plants...and people too. Deforestation contributes to climate change and can also lead to landslides and floods. We hear a lot about the rain forests in South America, Africa and Asia, but forests are threatened in other areas as well...including Europe. Bad wood is wood that comes from:

• Forests that are logged faster than they can regrow



• Old growth forests, which contain important and rare habitats and which can't recover from logging



• Forests that provide homes to endangered plants and animals



• Logging that is linked to crime and poor treatment of native people



• Logging that causes pollution or damage to the land

Buying bad wood is like buying a panda fur coat...and you wouldn't do that would you?

Now let's look at good wood. Wood is one of the few truly renewable materials we have. If we are careful about how we manage forests we can grow new wood to replace the wood we use. So long as forests are managed carefully they can provide wood forever. Indeed, thanks to responsible forestry for wood, the UK has more forests now than it had 100 years ago...and the forests are still growing.

Also, as trees grow they take carbon dioxide out of the air helping to combat climate change. When that wood is used to make products like furniture and houses the carbon is stored away and doesn't get back into the atmosphere until the wood product decays or is burnt...and that might be decades or even centuries. What's more is that we can make things out of wood that we would otherwise have to make from materials that cause environmental problems when they are made - like metals, concrete and plastics.

Forests can be factories for producing wood...and also provide lots of other good things too like homes for wildlife and nice places to go and exercise in.

So how can you know what's good wood and what's bad wood? Well, this is something that has been given a lot of thought in the last few years. There are now several "certification schemes" which aim to identify good wood. One of the best known is the Forest Stewardship Council (or FSC) which is supported by environmental organisations like Greenpeace, WWF and Friends of the Earth. You can find more information here and here. There is also an excellent virtual tour of a Finnish Forest explaining some of what is involved in sustainable forestry. And you can also learn a little more about the sustainability of different species by playing our timber trumps game.

Buying certified wood is a good thing...it encourages people to look after their forests. So look out for the certification marks.

Wood shrinkage

This is a delightfully retro video looking at the microstructure of pine wood and why it shrinks when it dries. It gets quite complicated with the terminology but has good visuals that help show how things work even if you don't understand the words. The things that look like air bubbles are meant to represent water droplets.

You might also want to look at our video about the chemistry of wood (on the firrs webpage).

Wood colour and chemistry

Here's a fun little video from the WoodWhisperer talking about how the colour of wood can change over time. This is all down to chemistry and something called oxidation. That's the same process that turns a sliced apple brown.

Sapwood is the outer part of the tree trunk - the wood that the tree is using to transport sap. The heartwood is the inner part of the tree trunk - the part of the wood that the tree uses to store waste chemicals...the extractives mentioned in this video.

As a tree ages the inner part of the sapwood slowly turns into heartwood. Heartwood provides structural support to the tree, but not much else and with very old trees it is common for the heartwood to be decayed away.

Different species of tree produce different extractive chemicals which explains why they can have such different colours.