Sawn Oak Supply
We can supply oak for all your needs. Below are a few examples.
Sawn Green Oak
We can provide sawn oak, cut to measure. Find out more about our cutting capabilities here.
Oak decking with non-slip profiles and grip-deck bauxite strips. Find out more.
We are specialists in oak construction. You can take a look at some of our past creations here.
Robust and attractive, we have made many oak boardwalks which you can see here.
We have the capabilities to cut oak beams, oak joists, and support columns.
Outdoor Oak Furniture
We can provide outdoor oak furniture in its complete form or supply sawn oak timber to make your own.
Is Oak Durable?
Yes, it is. On the TRADA durability class scale which ranges from 1-5, oak is classified as a class 2 timber which means that it is ‘durable’. In short, this means it has a life expectancy of 15-25 years when in an outdoor, unprotected environment.
What Are Timber Durability Classes?
We use timber durability classes as an indicator to the suitability of different timbers for different uses. Specifically, the durability classes relate to the ability of a timber’s heartwood to resist decay, often caused by moisture absorption or fungus, or infestation by insects such as termites or lyctid borers. The sapwood of any timber is classified as the lowest class, class 5, which indicates it is non-durable. Although the durability class system does not consider local conditions such as moisture, temperature, weather, competency of installation, and physical stress exerted upon timber, by paying attention to the durability classification of a specific species of timber, you can get a good estimate of how long the given timber will last.
Timber Durability Classes
The Timber Research And Development Association, TRADA, has defined five unique classes of timber durability ranging from 1 to 5 where 1 is the most durable – ‘very durable’ – and 5 is the least durable – ‘not durable’. Timber from each durability class has a life expectancy as detailed below:
We must reiterate that the timber durability classifications should be used as guidelines because local conditions can affect lifespans both positively and negatively. As oak is rated as durable, it will last longer than other, less durable timbers which is why we love it so much.
How Are Timber Durability Classes Measured?
Standard testing procedure is to take either a pole or steak of heartwood, then drive it into the ground and continue to monitor it over coming years. Combined with knowledge from timber experts, results from the timber’s deterioration are used to assign a durability class to each species of timber. If one was to test any hardwood in protected conditions, such as indoors with no risk of insect infestation, they would find that each hardwood timber has a lifespan of more than 50 years. However, durability is concerned with a timber’s lifespan in unprotected conditions.
What Is Heartwood And Sapwood?
Heartwood and sapwood are two classifications of the interior of a tree’s stem (or trunk). The heartwood is the innermost, dead part of a tree stem that compromises the majority of a tree’s cross section in mature trees, whilst the sapwood is the outermost, living part of any stem that transports sap up and down the tree. Heartwood is typically darker than sapwood, so it easy to see when you look at the cross section of any tree stem, as you can see in the picture below. Durability concerns the longevity of heartwood of different timber species because all sapwood is rated as class 5, non-durable.
Young trees consist only of sapwood, but as a tree becomes older, heartwood will form as the centre of the tree dies. The cells release a chemical when they die that causes the wood to become stronger and more resilient to insect attacks, whilst also changing its colour. This strong heartwood then gives a tree its structural strength whilst the sapwood continues to transport sap to where it is needed. Without the interior of a tree dying and forming heartwood, trees would not be able to grow as big or strong as they do.
You will notice different ratios of sapwood to heartwood in cross sections of different tree species. This is caused by the number of leaves and the speed at which a tree grows. Species that grow quicker, with more leaves, require more water which results in a higher percentage of sapwood. This is very clear in the cross sections above which show a large leafed maple on the left and small leafed black locust tree on the right. The larger leafed maple tree has a greater abundance of sapwood to heartwood, meaning that there is less usable timber in the tree.
Timber Durability Chart
The chart below shows the durability classes of 149 different timbers – 116 hardwoods, 29 softwoods, and 4 modified timbers.
Oak, The Best Of Everything
Combing a good level of durability with good environmental practices, oak is the perfect option for any outdoor structure. Sustainably managed suppliers are available in the UK, reducing transport emissions, and oak creations can be standing outside for decades. Class 1 timbers are generally extremely expensive or taken from badly managed forests so that they become endangered, whereas class 3-5 timbers cannot last outside long term without the use of harmful chemicals.
In short, we love oak and we use it constantly in our outdoor creations. We’re proud to be a British oak supplier and hope we can encourage more people to use this wonderful timber that is both durable and environmentally responsible. If you have any further questions about oak or its durability, please don’t hesitate to get in contact with us. We have decades of experience working with timber (centuries combined) and would be happy to advise you for whatever project you are undertaking.