Are you laying your decking upside down? Experts finally answer the question dividing the internet

If your decking is laid ridge-side up, the chances are you've got it the wrong way round. The correct way to lay decking boards for most decking is smooth-side-up, with the ridges there to prevent rot and mould.

Related: Garden decking ideas and designs for plots both large and small

Stephanie Savvides-Howell from @my_london_home posted a video sharing her discovery with her followers. Since her mic-drop moment, a debate over which way decking should go has been raging online. Ideal Home asked experts to settle the debate.

On Instagram, Stephanie from @my_london_home writes, 'I have a public service announcement for anyone that hasn't seen my stories. YOUR DECKING IS UPSIDE DOWN!'

'Yep, ridged side up? That's upside down. The ridges are to encourage circulation and stop the rot. They do not add extra grip. They are not meant to be seen. OK I'm done now. You're welcome.'

The Instagram video, which she shared last weekend, has attracted many comments as shocked homeowners come to terms with the news about their outdoor seating area.

'Far more pretty to look at. Who. Knew. Mind blown,' one commented.

Another said, 'Just told my husband. He initially looked at me like I was mad, but now he’s fully on board with this revelation.'

'I wanted them ‘the right way up’ but I was ganged up on!' wrote a third.

Laying decking with the ridges visible is certainly a lot harder to clean, as grime and mould gets stuck in the grooves. If your decking space is looking tired, our guide on how to clean and restore garden furniture will help.

'The news has spread like wildfire!' Stephanie tells Ideal Home. 'Some have taken the news better than others, but I honestly didn't expect it to be such a controversial topic! Lots of people have thanked me as they were about to lay down new decking and it's saved them from having to redo it!'

Stephanie also explains how she made the decking discovery. 'We've been documenting our garden renovation on my Instagram account. I mentioned to my followers how I was planning to place my decking "upside down" as I wanted a smooth finish on top,' she says.

'A few followers outside of the UK replied to my story asking "isn't that the right way?" After a bit of research, it turned out they were right!

'Other people got in touch after I shared the news with my followers that were UK based but knew carpenters and landscape gardeners that had always laid it that way.'

What is the correct way to lay decking boards?

Toby Allen from composite decking specialist NeoTimber comments that composite decking means you can avoid the debate entirely. He agrees that it's important to allow for enough airflow underneath a deck, but 'composite materials can be installed on either the grooved-channel or woodgrain finish as its make-up is better equipped to deal with moisture.'

According to Calum Maddock from home improvement website HomeHow, there is technically no right or wrong way to lay decking. 'It just depends on aesthetic and practical preferences,' he says.

'Most decking manufacturers advise ridge side down installation, as it enables air circulation beneath the boards, preventing excess moisture and mould.' He adds that moisture can decrease lifespan, so for long-lasting and robust decking area, go for groove-side down.

Browse all our garden ideas for more inspiration to help you make the most of your outdoor space this spring. Decking is a great garden landscaping idea to make your garden more functional all year round.

Related: Brilliant budget garden ideas – boost your outdoor space without breaking the bank!

So, it turns out the grooves really aren't for grip. Some decking has ridges on both sides for aesthetics, but generally, the ridges should be face down, with the smooth side on top.