Building your timber deck close to or right atop ground level offers a number of attractive advantages. The structure will be quicker to build than elevated decks, require less preparation and support and over the course of the project be a lot more economical.
There are, however, a few concerns that you need to address should you opt to go this route. Here’s how to maximise the advantages of building a deck at ground level.
- Low level decks do not require deep footings. You can use bolt on post shoes where appropriate and if you are going in ground you can use stumps into concrete footings (which are very easy to set)
- Ground-hugging decks do not require as much support for joists and so the frame design and structure may be simplified, saving on materials, labour and time.
- Moisture is the main concern when building any structure using timber. This is certainly more so for ground-level decks, which may be in close or direct contact with an abundant source of moisture — the ground. Therefore it is important the you correctly and adequately prepare the site. One easy way to control surface moisture is to dig up the build area and backfill with gravel. This allows water to drain off the surface through capillary action.
- Air circulation is another concern. Elevated structures have all the space for air to circulate underneath, minimising the threat of moisture buildup. But decks built closer to the ground may not have that luxury. Be aware of this requirement and adjust your deck design to include mechanisms for air to circulate underneath so the deck can vent out moisture.
The timber will be in close contact, if not in direct contact, with the ground and therefore be in greater danger from water and insects that can cause and accelerate decay. You can effectively neutralise this disadvantage by using treated timber with treatment level of at least H3.