Wooden Decking

Wooden decking

Wooden decking is an increasingly prevalent choice for creating outdoor seating areas in gardens. Due to the natural beauty of wood, they can be very fashionable areas that can be used year round by installing external heating and illumination. Wooden decking is often installed in locations in front of patio or French doors where they can create a seamless transition between interior and exterior spaces. Wooden decking can come in any size or shape to fit any area. Curved designs or large areas connected by pathways can produce a striking effect.

Wooden decking is relatively easy to install and causes little disruption, particularly when compared to alternatives like patio or paving. It can even be installed over the top of a pre-existing patio. It is essential however to be sure that your wooden decking is structurally sound and able to take the load of any furniture or plants that you would like to use on the decking.

There is a choice of species of wood that can be used in wooden decking. Typically decking is constructed from hardwood, but there are softwoods available that fulfil the durability specifications. As hardwood decking will require maintenance, which commonly requires yearly cleaning and staining for weather proofing, composite woods are becoming more popular for use in wooden decking as they are stronger and require significantly less maintenance.

Avg. price low	Avg. price low £765
Avg. price	Avg. price £2,746
Avg. price high	Avg. price high £4,718

Avg. price low

Avg. price low
£765

Avg. price

Avg. price
£2,746

Avg. price high

Avg. price high
£4,718

How much decking you need will – of course – depend on how big you plan your deck to be. There is an equation to help you work out how many deck boards you need. It’s a little complicated until you’ve been shown how it works, but once you know how to do it it’s easy to work out how much decking you need for any project. The equation takes into account the recommended 10% wastage and includes the expansion gaps that are required, which is between 5-8mm along the length of the deck boards (EGL, or expansion gap length) and 3mm along the ends of the deck boards (EGW, or expansion gap width) for timber. It also assumes you’re laying your decking horizontally, as if you’re looking for a diagonal or chevron design you’ll need more deck boards. Let’s go through an example, assuming you have a 10m x 6m area that you want to cover with decking made from timber boards that are 2.4m long and 144mm wide. We’ll use the EGL of 5mm and EGW of 3mm.

Calculate the surface area for your decking Multiply the length (L) of your decking area by the width (W): L x W = Decking Surface Area (DSA) in m² 10 x 6 = 60m²
Work out the coverage of your deck boards Add your deck board width (DBW) to the expansion gap length (EGL), then add the deck board length (DBL) to the expansion gap width (EGW). Then multiply these numbers. (DBW + EGL) x (DBL + EGW) = Single Board Coverage (SBC) 0.144m + 0.005m = 0.149m 2.4m + 0.003m = 2.403m 0.149 x 2.403 = 0.358m²
Calculate the number of deck boards you need Multiply the SBC by 1.1 to allow for 10% wastage. Then, divide the DSA by the SBC. DSA / SCB x 1.1 = Total number of boards required 60m² / 0.358m² x 1.1 = 184.36 boards – so round up to 185 so you’re not left short.

If that all seems a bit complicated for you, let a professional do the maths – they will be able to give you an idea of how much decking you’ll need in no time.

Usually, slipperiness is caused by algae or dirt on top of the deck or terrace. A full cleaning treatment should restore the natural grip of the wood or stone. If slipperiness is a persistent problem, consider installing grip mats in high traffic areas of the deck.

Yes, although you should make sure that the terrace or decking is able to support the weight of a hot tub. Usually, you will need to have a structural survey carried out on the area. Seek the advise of a hot tub retailer or installer about the logistics of installing one at your property.

You might think that building decking on a slope is a no-go, but it’s actually a great way to help you make use of your garden when the ground is sloping. It will provide you with a level surface that you can BBQ on as well as dine alfresco without finding that your meal is rolling down the table. But how do you build decking on a slope? Our guide in the FAQ above, ‘How to build a raised deck’, is the perfect solution – but we’ll break it down here if you just want to get an idea of what’s involved. Dig out the area If you’re laying on soil or turf, you’ll need to dig it out. Dig down and remove all the turf from the area and ensure that there are no weeds or stones in the area you’re going to build your decking on. Since you’re building on a slope, it will be hard to get it level, but dig out to a depth of 50mm and lay weed-control fabric with gravel over the top. Add posts and set with concrete Make holes for posts and add them in, ensuring they’re longer than you need. Make sure they’re level, then fill the holes with a concrete mix to set them in place. Build the outer frame Make sure you always work at the top of the slope when you’re building your decking, and measure where the highest point of the decking will be. Secure the 4 sides of the outer frame and factor in a 2mm fall for every metre of decking so rainwater can run off. Add joists Secure joists along your frame at 400mm intervals. If you get to the last joist and there will be more than a 400mm gap left at the end, add in an extra one for support. Lay your deck boards Screw your deck boards to the joists, ensuring that the deck boards are running in the opposite direction to the joists. For timber boards, you need to make sure you leave an expansion gap of 5-8mm. These steps should give you an idea of whether you want to have a go at building decking on a slope, or whether you want to leave it to the pros.

If your deck isn’t going to be flat to the ground, it’s a good idea to have some kind of balustrade to avoid any tripping. If the gap between the deck and the ground is less than 600mm, use a 900mm balustrade. If it’s higher than 600mm, the balustrade should be 1100mm tall.

Building a raised deck will take some time and is trickier than laying standard decking at ground level, but if you want to build decking on a slope or uneven ground it’s the best way to do it. If you do your research and follow instructions, you and a friend or family member can build a raised deck over a few days. Here’s a simplified guide of the steps you’ll need to take. Plan carefully It’s best to plan your raised deck by drawing it to scale on paper before you go and get supplies. This will help avoid wastage and making more cuts to timber than necessary. Prepare the area Prepare the area according to the instructions we give in the FAQ ‘How to lay decking’. However, because you’re building a raised deck, you’ll need to add posts:

Place a post in the corner of the frame you created with the pegs and string. Measure and mark out 100mm from each side.
Dig out this soil to a depth of 700mm (watch out for cables or pipes). You should have a 300 x 300mm hole. Repeat for the other 3 corners.
Using a brick bolster, split a concrete block in two. Put a section of the block in each hole.
Get a length of post longer than you need and place one in each hole. You can cut it down later.
Create props on each post to hold them in place until you’re ready to add a cement mix. Check that they’re level. When you’re happy that they are, secure them in place with a concrete mix, making sure you create a slope in the concrete so that rainwater runs away from each post. When the concrete is set, remove the props.
Create a string line around each corner post and find the centre point between each. Place a timber batten at each point, ensuring that they’re not spaced any more than 1500mm apart.

Make the outer frame

Working from the corner where the deck will be at its highest above ground level, measure and mark on the post where the highest part of the frame will be.
Measure from the far side of one post to the opposite and cut sections of joist to size. Line up a piece of joist with the mark you made and temporarily secure it. Factor in a 2mm fall for every metre of decking so rainwater can run off.
Secure the frame to the other corner post, ensuring it’s at the right level. Do this for every side of the outer frame.
Using 100mm coach screws with washers hanging on the end, secure each end of the four sections of frame.
Mark out where the centre of the support posts will be and secure all of these posts to the frame, except the centre post.
Add your central support joists. These should run in the same direction as the deck boards will run. You’ll need to measure from the inside of the frame on one side to the inside of the frame on the opposite side. Attach the joist in the same way as you did for the other posts. Repeat so the centre post is in between two sections of frame and secure the posts with concrete.
Trim down all the posts to the correct height using a saw.
Add your weed-control fabric and weigh down with gravel across the entire area.

Add your joists

Measure 400mm from the centre of the outer frame and mark a line. This will be where the first joist is positioned. Repeat at 400mm intervals down the length of the frame – if the last one will be more than 400mm, add another joist to create enough support.
Attach a joist hanger to each end of the joist.
Place the joist in position so the centre lines up with the 400mm spacer mark.
Secure using external grade screws once you’re happy that the joist is flush with the frame.

Lay your decking boards Refer to our FAQ on how to lay decking to see how you should attach your decking boards. Remember: Always treat cut ends and pilot holes with decking preservative to keep your decking in good condition for as long as possible. Building a raised deck isn’t a straightforward task. If you’d rather leave it to the professionals, get a range of quotes to help you get the best price and a high quality finish.

There are two ways to lay decking on uneven ground. We’ve explained how to build a raised deck in our FAQ ‘How to build a raised deck’ above, and that’s great for uneven ground or sloped gardens. But there’s another way that you can lay decking on uneven ground if you don’t want a raised deck: you can create a level supporting base. We’ll go through the basics here. Materials you’ll need

Paving slabs – old or cheap ones are fine
Timber for the frame and legs
Type 1 MOT hardcore

How to lay decking on uneven ground

Mark out the area as we explain in ‘How to lay decking’. Then, dig to 200mm below where you want to surface of the decking to be.
Add a 50mm layer of hardcore and make sure it’s compact.
Build the decking sub-frame as we describe in ‘How to build a deck frame’.
Lay out paving slabs along the edges and in the centre of the area. This will help to spread the weight of the decking.
Set the decking frame on the slabs, checking for high or low points and adding off-cuts of timber where needed. Don’t forget to sand and seal these off-cuts with decking preservative.
Add your joists and then the deck boards, leaving the recommended gaps of expansion of between 5-8mm.

Building your decking on top of paving slabs is a good way to get it level, but you still may not be able to get as good a finish as if a professional did it. If you’re in any doubt, get in contact with some decking specialists and see what they would recommend.

Properly installed wooden decking will not need a lot of maintenance. Most manufacturers recommend regularly brushing leaves and dirt off the deck, and a yearly cleaning and staining procedure. This will keep the wood in the best condition. Fluids and treatments are readily available from all DIY shops and stores.