When shopping for outdoor decking, many people only think about the colour and style of the decking board. Most forget about what goes under the deck. Not the dirt, the deck frame.
Constructing a sturdy deck frame requires careful thought. If your frame posts are in or touching the ground, you’ll need to ensure the pine is properly treated (H4 and above). If you use untreated wood or choose timber with the wrong treatment, your deck frame can be susceptible to insect damage or decay.
Let’s take a closer look at why pine is the preferred timber for deck framing and what varieties of treated pine are available.
What are the benefits of a treated pine deck?
There are three obvious benefits when using treated pine for your decking.
- Cost Effectiveness
Why is treated pine so strong?
While pine may technically be a softwood, it has an extremely high compressive strength. Even under heavy loads, pine will not fracture. In fact, the compressive strength and bending strength of pine is on par or better than many hardwoods. For those DIY’ers who are building their deck frame, pine is the perfect wood because it’s lightweight and easy to cut.
Get more for your money
In short, pine is a cheaper alternative to other timbers. Pine trees grow fast, require less care while growing and are often grown in government-run plantations. The regular supply of pine keeps the price lower than its hardwood counterparts.
Treated pine is long lasting
With the correct treatment applied, pine deck frames have been shown to enjoy a long lifespan. While it’s difficult to say exactly how many years you’ll get out of your pine structure, a lot depends on the purpose the pine is used for, i.e. whether used in or above ground and the surrounding climate conditions.
Choosing the right treated pine for your deck?
Treated timber is divided into six categories. They are classified according to their hazard (H) class. The higher the number, the greater the level of treatment.
H1 – H1 treatment is designed to reduce the chance of insect or termite attack. You should use H1 treated timber in well-ventilated areas. The timber should be kept away from the ground and not be exposed to the weather – especially moisture. H1 timber is generally used indoors for flooring and furniture.
H2 – H2 treated timber is slightly more resilient than H1. While it’s still advised to only use this treated timber indoors, the area your timber is located doesn’t need to be as well ventilated. H2 also minimises insect attacks.
H3 – This type of treated pine is commonly used for deck frames. The wood must be kept off the ground with a minimum clearance of 50mm, but it can be exposed to moderate wet weather. H3 treated pine is perfect for pergolas, decking and cladding.
H4 – If you need to install your timber in the ground, H4 is the lowest level timer that is safe to do so. The treatment will reduce insect and fungal attack, even if installed in ground that is constantly damp. H4 treated pine is ideal for fencing posts, landscaping timber, pergola posts and, of course, deck frame posts.
H5 – If you need to install timber in the ground or freshwater for long periods, H5 treated timber can handle the task. The treatment is designed to protect against extreme decay as well as to deter attacks from insects.
H6 – Carrying the highest protection level, H6 treated timber is commonly used for boat hulls, jetties and similar applications that are exposed to seawater. The H6 treatment reduces the chance of extreme decay or attack from marine wood borers.
If you want to find out more about treated pine for your outdoor deck frame, talk to the experts at Decking Perth. We can help you choose the right treated pine for your project to ensure you get the longest life and prevent any nasties like moisture or termites from damaging the wood.