Decking

Building A Deck On Concrete

A wooden deck provides an ideal place for to sit out, or where you need an area raised above ground level. It can be integrated with a fence or a roof covering. This deck is about 300mm above the ground and is a maximum of 3,200mm wide. It can be as long as you like, but is shown here at about 3,700mm, suitable for three pairs of chairs.

Decking should be well-ventilated, free-draining (with a gap of 5-8mm between boards) and capable of bearing any loads placed on it.

Attach outer cover boards about 5mm from the outer edge of the posts and a minimum 10mm if the deck connects to the house wall. Fasten joists to posts with joist hangers with inward tabs. Fix a 28x45mm bearing strip to the bottom of each joist for the rails to sit on. Screw the deck boards directly to the joists. Use proprietary stainless steel countersunk decking screws. If you want to make a step, the easiest way is with a 45x145mm frame, using a joist for the tread. The step can be made in any width and placed directly on the ground.

For more information our guide to timber decking or visit www.tdca.org.uk

Building A Ground Level Deck With No Concrete Base

Build the deck as so close to the ground as possible. This deck is about 300mm above ground level. Clear all vegetation from under the deck. Lay weed-suppressing sheeting secured with clips or gravel (about 100mm deep). Build a box frame with your joists directly onto the gravel surface. You can use a stake as shown to secure the frame. Screw deck boards directly to the joists. Fix a cover board to protect the end grain of both the decking and joists.

Use the same construction for paths, as a good alternative to slabs. Level differences can be resolved by using vertical joists supported by stakes driven into the ground.

For more information our guide to timber decking or visit www.tdca.org.uk

NameCross-Section mmLength mm (Drawing Size)Gap mm
Posts95 x 95270 beneath decking1700
Joists45 x 1703025c.1700
Cover boards22 x 1701700c.600
Rails45 x 951700c.600
Support Strip28 x 453025-
Deck Boards28 x 1203215c. 3-5

NameCross-Section mmLength mm (Drawing Size)Gap mm
Horizontal Joists95 x 95Varying500
Joists45 x 145Varying500
Cover boards45 x 95Varying-
Deck Boards28 x 120Varyingc. 3-5