Why Use Timber?
The best material to use for your greenhouse is a heavily debated topic – here’s our take on it
We’re in the business of making traditional greenhouses and traditionally they are made from timber. You get a warmth and solid feel from timber that you don’t get from metals and plastics and it insulates better. Some timbers, however, are susceptible to decay over extended periods outdoors and can twist and move when exposed to moisture and different temperatures. Cedar is different. It contains natural extractives that are toxic to many fungi and bacteria that usually attack other timbers. Unpainted cedar will last for years outdoors but eventually rain and sunlight remove oils from its surface and it becomes tired and damaged turning grey and pitted. Painting it locks in the extractives and further protects the outer surface.
As a building material it’s carbon negative:
Cedar is dimensionally very stable which means its size and shape alters very little as it absorbs and releases water vapour from the air around it. This makes it ideal for use in greenhouses where the environment can change regularly. We have successfully used cedar for many years in our greenhouse framework and to produce our unpainted staging and shelving.
We now use Accoya® wood as well as cedar to add greater levels of durability, stability and paint retention in key areas of the framework. Accoya® is a non-toxic, high performance wood product produced by Accsys Group using their proprietary acetylation process. The modification procedure chemically alters the wood’s free hydroxyls into stable acetyl groups. This means the ability of the wood to absorb water is greatly reduced, rendering Accoya® dimensionally stable and extremely durable.
Accoya® Key Features:
- DIMENSIONALLY STABLE
Swelling and shrinkage reduced by 75% and more
- OUTSTANDING DURABILITY
Lasting 50 years above ground, 25 years in ground/freshwater
Class 1 durability
Virtually rot proof
70 year minimum service life stated by TRADA
- PERFECT FOR COATING
Improved stability means coatings last up to two times longer
As a building material timber is carbon negative: the carbon absorbed from the atmosphere as a tree grows is locked away when it’s cut down. When a new tree is planted, more carbon is locked away. It also uses far less energy to convert a tree into a useful material. By comparison, it takes about 20 times more energy to produce a kilogram of aluminium than it does to produce a kilogram of timber.