We all know that we need to reduce the impact we have on the world around us. We need to use less, protect natural environments, stop littering and reduce our carbon footprints. When we do need to buy or use something it is not always easy to make informed purchasing decisions. How do you measure how sustainable something is and how can a product or service be labelled accurately so that we as consumers can make informed decisions?
Building materials, be they used structurally or for things like windows and floors, are usually used in large quantities and consume correspondingly large amounts of resources such as energy and raw materials. Therefore, they can have a large impact on the environment and we should all make sure we are making intelligent environmental decisions when we acquire these materials. The good news is that this is actually quite easy to do.
What Is Sustainability?
Good question! There are lots of ways to think about it;
1. The ability to meet the needs of the present without compromising the ability of future generations to meet their own needs.
2. The quality of not being harmful to the environment or depleting natural resources, and thereby supporting long-term ecological balance.
3. A method of harvesting or using a resource so that the resource is not depleted or permanently damaged.
Why Is Timber So Sustainable?
This is why timber is such a sustainable building material when compared to traditional substances such as aluminium, plastics or concrete. Aluminium and concrete require large scale mining operations which destroy habitats and cause pollution. Compare this to sustainably grown timber – the forests are a carbon sink, provide rich habitats for animal and plant life and do not cause the destruction of existing wild habitats. The graph below compares the CO2 emissions of different building materials from birth to disposal which shows the drastic difference that choosing wood, particularly sustainably grown wood, can make.
It is easy to buy sustainable timer with confidence. In the USA and UK the main ways to demonstrate timber is sustainable is by obtaining certification from either the FSC® (Forest Stewardship Council) or PEFC® (Programme for the Endorsement of Forest Certification). You will have seen these badges on a range of products from timber, wooden furniture to napkins and envelopes.
If a product has these certifications then they timber they use comes from sustainably grown and managed forests. These certifications have been trusted for decades and are used around the world so you can buy with confidence when you see one. Choosing sustainable timber where you can rather than aluminium, concrete or plastic materials is a great way to ensure that your homes and gardens are as green as possible.
Sustainable Timber and Durability
Sustainable forests are almost exclusively softwood and what is one of the biggest differences between softwoods and hardwoods – oh yes, they are softer! Because they are softer it means they are not as strong, they bend and warp more and they are less resistant to attack by moulds and termites. All this adds up to materials that are not as strong and do not last as long. This is why people are tempted to use aluminium, concrete or hardwoods instead.
However, you will be pleased to hear that you can have the best of both worlds; sustainable softwoods that are treated so that they have the strength, durability and long life of hardwoods. The chemical reason hardwoods are superior to softwoods is that they are not as reactive to water. Water causes shape changes and allows insects and moulds to live in the wood. So, if you could prevent water from reacting with the softwood then it would magically gain the superior performance characteristics of hardwoods. There are lots of different treatment methods which do just that but they have different degrees of effectiveness and different environmental impacts;
1. Coating. Just painting timber can reduce the ability of water, air, insects and mould to access the wood thereby extending its life. However, this takes time, frequent reapplications and the coatings themselves are often bad for the environment and our own health.
2. Penetrating treatments. Ever smelt a railway sleeper? That strange tar smell is due to the fact the timber has been soaked in petrochemical based substance. There are lots of these penetrations (remember creosote fence paint?) but they all prevent water absorption and are toxic to insects and moulds. Brilliant at extending the life of timber but terrible for the environment and our own health.
3. Non-toxic treatments. There are heat and pressure treatments that go some way to extending the life of softwoods but few get them anywhere close to the performance of hardwoods. One that does is acetylation. This is essentially timber pickling! The process changes the molecular structure of the softwood to mimic hardwood. The result is an incredibly strong, long lasting material that is also sustainable. The best example a commercially available acetylated wood is Accoya
Making environmentally sound decisions is important. Choosing sustainable timber to use in and around our homes is easy to do because there are established and trustworthy labelling systems in place. Untreated softwood can work well if strength or exposure to the weather is not an issue. If it is then you can find non toxic treatments that will boost the strength and extend the life of sustainable softwoods so you can use them in any application.