Outdoor decks are a beautiful addition to any house, and if you have the space, time, and know-how to build one, then there's no reason you shouldn't. But the first question you need to answer after deciding to go through with it is what type of timber to use for your deck. There are several viable timbers that can be put together to build a fine deck, and to the average layman, you might assume the only difference between them is colour. There are actually a few factors you should consider when choosing your timber.
Types: Softwood, Hardwood, Composite
Decking timbers are divided into three types: softwood, hardwood, and composite. Generally, composites are man-made mixtures of plastics and organic materials, softwoods are cut from coniferous trees, and hardwoods are broad-leaved trees (the difference between these two is whether the tree protects its seed with a thicker shell).
These are generally the most popular choice of the three, because they are cheaper and more malleable, making them easier to work with. They're resistant to harsh weather conditions, termites, and rotting, and require minimal maintenance after installation.
These are typically much more durable than the other options, however with a much costlier price. The color of hardwoods is also naturally more vibrant and rich, but installation is more difficult, and it also requires more upkeep and maintenance after installation than softwood timber.
The composite timber is best used when a larger project is required, as composite boards can be mass-produced through manufacturing, making them much cheaper in bulk, and are available in a variety of lengths, widths, colors, and textures. However, due to the synthetic material, they are much more susceptible to weathering damage, such as expanding under the hot sun and absorbing the rain, which makes them the worst material for outdoor decks.
Seasoned vs New
You should also consider whether you want seasoned timber or new timber. While it may be more tempting to opt for new timber, seasoned timber is actually much better, assuming it has been treated properly during the seasoning. This is because new timber still has much of the original moisture content, meaning the wood might still shrink, warp, and twist, thus ruining the timber and the deck. When finding your timber, be sure that it has been seasoned correctly. Hardwoods take more time and effort because of their denser material, one of the reasons for their higher cost.
H Level Treatment
When prepared, specific levels of treatment are introduced to the wood to protect them against certain hazards, or H, and what H level you need is important in picking your wood. The H levels consist of the following:
- H1 – Indoors and above ground, protected against average insects.
- H2 – Indoors and above ground, protected against termites.
- H3 – Outdoors and above ground, protected against decay and termites.
- H4 – Outdoors and on ground, protected against severe decay and termites.
- H5 – Outdoors and on ground or freshwater, protected against very severe decay and termites.
- H6 – Marine water, protected against marine wood borers and sever decay.
The type of timber decking you need is highly dependent on the location of your decking, your budget, and how long you wish your decking to last, so choose wisely.