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Build your own decking - the ultimate DIY landscaping project

For those who may have considered an outdoor decking area one of the leading considerations is usually cost, and little wonder given that this home improvement can easily reach the lofty budgetary heights of upwards of £1000.

Yet despite so many homeowners typically choosing to go to the professionals for such a service, building your own decking is surprisingly straight forward with the right instructions. With this in mind here we provide a step-by-step guide towards installing your own decking – simple, straight forward and with just enough detail.

Build your own decking: Step by Step

1. Prepare your site

Begin by cleaning out all vegetation, debris and trees that are currently upon the site where the decking will be (it is very important to avoid digging into any cables and drainage and using Cable & Pipe detector really helps to prevent that).

Next you should measure out the area using your deck plan (which should have been drawn up prior to so much as purchasing a single piece of decking); use pegs to place within the ground to mark off the decking corners.

If the area has grass down then you’ll need to dig this up and smooth over the left behind soil so that you have a flat surface to work with.

2. If the deck is to be connected to a building now is the time to attach the joists

If your decking is to attach to your building then you firstly need to be sure that it won’t be blocking any airbricks, nor disturbing any damp-proof course.

Next you should hold the joist against the masonry and then align the sub-frame to run alongside it. The holes within the joist should be placed with 400mm in-between them across the entire length of the joist, they should also be placed at the top and bottom in turns (this ensures no area of the joist is weakened).

Lastly you should ensure that the joist is completely level with a spirit level, following this by drilling the holes into the masonry and placing expanding masonry bolts (with washers) into the holes. Complete the process by ensuring that these are as tight as possible with the help of a spanner.

3. Check your decking area is square

Before you begin any structural work you need to ensure that the area is square (you should use the 3-4-5 triangle method to achieve this).

4. Add your support posts

Begin by digging holes that are 600mm deep for each of the joist support posts, these should be around 300mm in diameter at the top and 400mm at the bottom. Between each post there should be 1.2m. The corner posts should not sit right in the corner of the site, but should instead be slightly inset.

Having placed the post in the hole you should then check it’s completely level, hold it in position and pour in quick drying cement. Repeat this for each hole.

5. Build your joist sub-frame skeleton

Next you should attach an outer edge of joists, forming a square and fixing the joists first to each corner post with two countersunk coach screws, and then to one another at the corners with two countersunk coach screws once more. You can make this more secure by adding two parallel support beams to every other post (if you only have a three by three posts square, the support beam would be in the middle only).

Next you should add the inner joists, which should run in the opposite direction to the deck boards that you’ll eventually add.

6. Add your railings

The simplest and most secure way to add railings to your decking is to purchase these pre-made from a DIY store. Then you can simply attach the rails by drilling the corner posts into place.

7. Lay the deck boards

Begin laying your decking boards by working from the out edge, inwards. Mark out where you should cut your decking pieces and then saw them down. The two decking pieces that are at the edges will additionally require the cutting out of a section to account for the corner rail poles.

Continue inwards and screw each decking piece down onto the joist that’s immediately below. The layout of your decking pieces should be staggered so that they avoid a block pattern.

8. Fit the skirting panel

Skirting panels can be attached easily and simply by using pre-constructed lattice panels and a wire mesh staple gun attached to the back to stop any unsightly debris from collecting underneath your decking.

9. Consider adding a gate

A gate may be helpful if you have small children or pets whom you want to restrict access to; gates are available ready made from any good DIY store.

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Contact Plantool for expert advice on freephone 0800 334 5365

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