What you should know about timber
There are a few things to look at when buying timber. This could be if you are going to buy timber from a timber merchant or DIY store, or even if you are buying a whole climbing frame to build yourself.
The key points to look at, or at least be aware of are:
- How the timber was dried (seasoned timber) Wood is a natural product that contains a lot of moisture - some trees more than others. There are different methods used in drying out timber and you need to make sure that your timber has been 'seasoned' or dried before you use it to make play equipment. These are usually either Kiln Drying or Air Drying. Kiln drying simply means that heat has been introduced in the drying or 'seasoning' process. Air drying is when the wood is dried (usually in stacks) in the air and although this process can take a lot longer it can produces a higher quality timber than when kiln dried. Kiln drying is a more regulated and speedier process. The levels of moisture, heat and drying conditions can all be monitored to provide a quicker and more controlled drying process.
- Which part of the tree the wood is from Wood can be taken from the centre of the tree (the heart) or the edges. The wood in the centre of the tree is called the 'heart wood and it has been transformed chemically to become more resistant to rot and decay. Once the heartwood has formed in a tree it is technically 'dead' - the sapwood being the younger, living part of the tree. The heartwood fo a tree is a lot older than the sapwood and therefore is usually stronger - but this is not the case with every tree as heartwood can sometimes rot or become infested dependant on age, size of tree, conditions etc. etc.
- The treatment on the wood Some woods is naturally resistant to rot and insect infestation, although most wood is prone to damage of some kind. There are various different ways to treat wood. The main ways timber is treated is either by pressure treatment or painted on stains. We would strongly recommend wood that has been pressure treated. This is because the treatment then penetrates through the wood protecting the entire timber beams. Treatments that have been painted on require renewing on a regular basis. There is always the option of buying pressure treated timber and painting on a preserver for added durability. Read our guide here on wood treatments for more information.
What type of timber is best?
This is a moot point amongst many manufacturer's, timber merchants and the whole of the DIY world. We would say the question to be asking is which timber will suit my climbing frame best? Naturally, one would think the strongest timber would be best, but if you are making your own climbing frame sometimes the strongest timbers are the most dense, making them hard to work with.
If you are creating your own climbing frame or swing then the design may affect the type of shape of timber you want to buy. But depending on what type of timber you can purchase and how much you can afford may affect the design too so you may want to do some timber research before making any concrete plans.
If you are looking at buying a climbing frame, then you may want to know which brand is made from the best timber or what the differences are between the timber used by different brands (where known).
Here we have gathered as much information about the different timber which is readily available in the UK, so you can make an informed decision about what you are buying.
The crushing strength or compression strength is a good indication of the strength of the wood, as it is measured by force being applied to the ends of a piece of wood parallel to the grain. You can compare the crushing strength of each wood against each other (as on its own the number won't mean an awful lot on its own!)
There are over 100 species of pine, and 35 species of spruce all with varying characters and qualities. These are often used for timber so we have detailed a few that are known to be currently used by brands.
If you are looking to buy your own timber - and aren't sure what wood you are buying, look for the Latin name. The 'pinus' in a name means it is a type of pine and 'picea' will mean it is a type of spruce.
|Tree Species||Norwegian Spruce||Scots Pine||Chinese Fir||Western Redcedar||Douglas Fir|
|Latin Name||picea abies||pinus sylvestris||cunninghamia lanceolata||thuja plicata||pseudotsuga menziesii|
|Also Called:||whitewood||redwood||cypress, 'cedar'||taxifolia||Found In:||Northerns & Central Europe (but grown in US & Canada too)||Europe and Northern Asia||China, Vietnam, Laos||US & Canada||UK & Europe|
|Used by:||Jungle Gym Climbing Frames||Jungle Gym Climbing Frames||Selwood, Dunster House and some Plum products|
|Texture||Straight grain, even texture||This wood has a straight grain and a medium, even texture.||Grain is generally straight, though wavy or curly grain is occasionally seen. Medium to coarse texture.||Has a straight grain and a medium to coarse texture.||Medium to coarse texture, grain is generally straight but waves can be seen occasionally.|
|Compression Strength||35.3 MPa||41.5 MPa||34.9 MPa||31.4 MPa||47.9 MPa|
|Density||405 kg/cubic metre||550 kg/cubic metre||400 kg/cubic metre||390 kg/cubic metre||510 kg/cubic metre|
|Other Qualities||Does not naturally repel rot although heartwood is naturally resistant to decay - can easily be pressure treated (staining can be difficult, sealer or gel stain is recommended).||Does not naturally repel rot and infestation, although can easily be pressure treated.||Natural resistance to rot, pests and fungus, cannot be treated but can be stained.||Easy to work with, very durable to rot and decay.||Moderately durable, really tolerant of extreme changes in climate.|
|Pricing & Availability||Construction grade is cheap and easy to get hold of||Commonly used and moderate in price||Not as readily available to buy as other timber although very cheap to buy||Fairly easy to get hold of, moderately priced, quarter-sawn timber is more expensive||100kg (on 8ft) - 140kg (on 14ft)|
Key Points: Choosing Timber Wisely
For all DIY climbing frame projects, we have summarised the key things you should look for when choosing the right timber for your play equipment:
- Buying higher quality timber will ultimately make your play equipment of higher quality and last a lot longer - it can be a false economy to buy cheaper materials. It will also be more frustrating when building if working with cheaper timber and will not look as nice when completed
- Make sure you buy pressure treated timber (or ask your timber merchant for timber which is protected against rot and insect infestation)
- Some wood are naturally less prone to infestation and rot, these are:
- European hard woods
- Tropical hard woods
- If your wood does not have a natural resistance to rot then a pressure treated timber is essential (read our treatment guide here)
- Choosing strong timber for the top beam of a swing set is essential. If you want to double check the strength of your timber, you can suspend it between two crates and jump a short distance, landing back onto it - creating a greater applied force than your own weight. If the wood does not crack or break this should be strong enough but it is usually better checking the timber merchant's recommendations for strong timbers.