How Polluting is Timber?

Introduction

Before we dive into this, we just need to quickly explain the term 'embodied carbon'. Essentially, this means how much carbon dioxide is emitted through a material's lifespan, including manufacturing, transport, during its usage and at the end of its life. The more energy the product requires to be brought into and out of existence will determine its embodied carbon—or in other words, how polluting it is. 

wood stacked up in a frosty winter woodland


How polluting is it?

We'll focus on softwood, as that's what our products are made from. Softwood timber emits, on average, 250g of embodied carbon per KG of material. That figure doesn't mean much on its own, but to put that into perspective, aluminium produces 17kg of embodied carbon per KG—68x more! 

How is this calculated?

The stark difference between these materials is largely down to the energy needed to harvest and process both. Timber is felled, planed, transported, made into a product—in our case trusses & joists—and transported again. Most of the cO2 emitted is transport, as much of it comes from Scandinavia. Once softwood reaches the end of its lifespan, it's recycled or simply composted. 

In comparison, aluminium processing begins with the extraction of bauxite ore, which is refined through the Bayer process to produce alumina (Al₂O₃). The alumina is then subjected to electrolysis in the Hall-Héroult process, where it is dissolved in molten cryolite and reduced to liquid aluminium at the cathode. This liquid is collected and cast into ingots, billets, or slabs. These are then rolled, extruded, or forged into various products, often receiving surface treatments like anodising or coating to enhance properties like corrosion resistance. As you're now probably aware, it's a bit more labour intensive.

 

aluminium being melted and poured in a factory


What are the other advantages of timber?

Most of us are aware that trees produce cO2, however what many don't realise is that they are able to store this even after the felling process. According to a BBC article from 2019, homes made primarily from timber captured over 1 million tonnes of cO2 annually. 

If you're constructing your next home, garage, shed or commercial building and need some roof trusses or joists, let us know below and we'll provide a comprehensive quotation completely free of charge. 

 

 

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