Experts reveal 7 decking mistakes and how to avoid them

Decking mistakes can be costly, not to mention an eyesore too. Avoid these DIY deck disasters and surficial shortcomings in your backyard

An outdoor space with decking, dining area with outdoor table, stairs, BBQ and decking decor
(Image credit: David Giles Photography)

To avoid making these disastrous decking mistakes you'll need to be cautious about your approach, especially if you're trying your hand at decking to save some money.

Decking your backyard out with a stable foundation is a fine way to finish your external scheme. However big or small your deck ideas are, paying your due diligence is a fundamental part of the process. From buying your boards to deciding on the space you want to cover, pest control, and futureproofing your outdoor floor, there are some crucial considerations to make if you're thinking about trying out this garden project.

So, we have spoken to the experts to find out what not to do...

1. You're installing it the wrong side up

A backyard area with decked surface and two garden chairs

(Image credit: Megan Taylor)

Thought it was 'groovy' to have the textured side on top?

Despite the common belief that you should lay deck boards with the groove side up, it’s actually more effective to have the smooth side showing. This is because the grooves encourage air circulation beneath the deck which stops it from rotting. There’s no real extra grip achieved through having the ridges up and they can increase the difficulty of cleaning your deck.

'Laying your own decking may seem simple especially if you’re an experienced DIY-er but it doesn’t come without its difficulties,' says Harry Patte-Dobbs, garden expert at

'The most surprising thing people find they’re getting wrong is installing the decking with the grooves facing up. These grooves might only help with water runoff if built on an angle, so if you want your decking to last a long time it’s best to have the smooth side facing upwards.'

2. You've gone overboard with coverage

An outdoor area with pergola, L-shaped outdoor sofa, decking and gravel decor

(Image credit: Future)

Make sure you carefully plan how much of your garden you want to cover with decking. Too little and you won’t have enough space to fit garden furniture and your deck planter ideas on. But too much and you can lose the natural feel of the garden - leaving no space for wildlife to flourish.

Whether you're planning for a large or small deck idea, getting your proportions right is essential for an attractive external aesthetic.

3. You've not allowed for gaps

As wood is a natural material it will expand and contract under different conditions. When humid, wooden decking can expand, and when it's cold can contract.

Composite decking won’t warp like real wood. However, it can change size depending on the climate. So it’s important to leave a gap between the boards, as it gives your deck adequate space to change without damaging the structural integrity
If you're still confused, our guide on how to install decking lays everything out plain and simple.

4. You're using poor-quality wood

They say a man is only as good as his tools, and the same could be said for building materials too. If you want durable decking, then it’s worth investing in good-quality hardwood or opting for composite decking instead of softwood. 

They're also less likely to become a safety hazard which will be top of mind if you like hosting and/or have a young family.

5. You're providing shelter for pests

Underneath the deck can become a rat’s new home if you don’t make sure there aren’t any gaps for them to crawl into. You can do this by filling in the deck frame with hardcore, soil, or any other available material.

If you want to be extra cautious, you can put chicken wire (easily found on Amazon) or mesh around the edge of the decking, although this may affect the overall aesthetic.

6. You're overcomplicating the design

An outdoor dining area with decking, and black table

(Image credit: David Giles Photography)

As with most interior and exterior design: less is more. Especially when you’re doing a DIY job. Adding garden benches, backyard lighting ideas, and even your own DIY alternative planter designs are all ways to zhuzh up your decking but do these things separately. Adding too many deck decorating ideas can make it look cluttered and lead to mistakes when cutting and installing.

Having lots of stuff on your deck makes it harder to clean too. Dirt, moss, and algae can all ruin your decking, so it's important to use a deck cleaner to stop these things from degrading it.  

7. You're not sealing the deck straight away

If you don't want your deck to get destroyed by Mother Nature: seal it ASAP. Newly-installed wood is in the best condition to be coated and sealant is easy to come by. It can be found in most home improvement stores, and even online on Amazon.

The best decking oils can protect your outdoor floor from rain and UV sun damage and oiling a deck isn't as scary (or slippery) as it seems. If you want to add a splash of color, even quick-drying exterior wood paints and decking paints have weatherproofing properties in the formula. 

Christina Chrysostomou
Former acting head ecommerce editor

Hi, I'm the former acting head ecommerce editor at Real Homes. Prior to working for the Future plc family, I've worked on a number of consumer events including the Ideal Home Show, Grand Designs Live, and Good Homes Magazine. With a first class degree from Keele University, and a plethora of experience in digital marketing, editorial, and social media, I have an eye for what should be in your shopping basket and have gone through the internal customer advisor accreditation process.