How to lay decking & build a decking frame

What Do I Need?

For this example, let's say that your decking area is 3.6m x 3.6m and on nice level ground.

How Many Deck Boards Do I Need?

Simply, 8 boards cover a meter. So we sell 3.6m deck boards (no waste) and you would need 29 boards. We would recommend to add a few spares, to allow for mistakes or to edge the deck area.

What Size Joists Do I Need?

If it is a standard deck with just a table and chairs sitting on it, 4 x 2" (100 x 50mm) joists are strong enough. However, if you are looking for strength and are putting heavier objects on the deck, we would recommend 5 x 2" (125 x 50mm) or 6 x 2" (150 x 50mm) joists.

At the end of the day, it is better to have as much strength as possible.

How Many Joists?

So thinking back to the size of our deck, 3.6m x 3.6m, we now need to work out how many joists we require.

We recommend 450mm spacing's between joists across the length of the area. The joists run the opposite way to the deck boards.

This would work out to 8 joists, however, you will need spare joists to build the outside of the frame and extras for noggins in between the joists for strength. So it's best to add 5 extra joists or so.

Remember that the strength of your decking is in the frame work, not the actual deck boards themselves.

Stump posts?

Normally 4 x 4" (100 x 100mm) stump posts are dug into the ground and concreted in, to help give the framework stability.

These are fitted every 6ft (1.8m) across the whole deck. So in our example we will need 9. If the ground is level as we have mentioned previously, the posts will only need to be around 2ft (600mm) in length, 300mm in the ground, 300mm out of the ground.

Then bolt, or timberlok the joists to the stump posts when leveled.

So in this example, we will get 4 stump posts from a 2.4m 100 x 100mm post, so we would need 3 x 2.4m posts.

This gives you some leeway so that you can extend the posts higher than your deck and cut level once the frame is finished.


Each 3.6m deck board needs approximately 12 screws, so we will need around 420 screws.

You can nail or screw the framework together, 100mm nails are fine or 100mm screws. Screws are easier to use as you can move joists about once fitted if required.

Optional extras are, joist hangers, landscape fabric or a new hand saw?

**Top Tip** Remember to allow a very slight run off so that water doesn't collect on the deck itself. It's best to allow the deck to run off away from your house.

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If you live in the following areas, we can deliver your new decking direct to your door:
Leamington Spa