Can you install decking boards with grooves up?

Been meaning to post this for a while. A few weeks ago I was at a mates place and noticed his deck had decking boards with the grooves. I told him I thought they were supposed to face down. He said they were meant to be that way so you don't slip, which didn't sound right. Is it just preferance or are you definitely meant to install decking boards with the grooves on the underside facing down?

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Comments

Jackson

@Farleys - you're both kinda right.

The grooves are non-slip. You'll see a lot of people use grooves if they have a ramp or steps off their deck. However, the grooves are actually there for air circulation underneath the boards and manufacturers recommend you install your boards groove-side down.

I'd just say go with whatever you think looks better.

AHoy

Nah, it should be grooves down. No debate. You might even void the manufacturer's warranty if you install them upside down. If you need a non-slip surface, then use an appropriate sealant or textured strips. The grooves should be face down as they are there for airflow and to stop moisture build up. If they are face up they will soon be full of grit and grime and algae etc and will become even more slippery.

Jackson

https://www.workshop.bunnings.com.au/discussion/comment/1844#Comment_1844

Well @AHoy - Workshop is a discussion forum so I'd say debate is probably considered mandatory.

Just for some anecdotal evidence (the best kind), my brother-in-law (carpenter) has his ramp groove-side up and it isn't slippery at all. He has had no issues with rot or algae, and older relatives enjoy the extra grip.

To your point about warranty, you probably void the warranty by not having it installed by a licensed carpenter too. You probably void the warranty by not using the recommended products to clean and oil it. You probably void the warranty by not cleaning it weekly and oiling it twice a year. I've never even heard of anyone using a manafacturers warranty on a deck to be honest. I'd consider that point pretty moot.

I'm sure you'll use some Google-fu to prove me wrong but I think you're just a bit too much of a by-the-book type of character, @AHoy. You sound like the type of bloke who goes to parties and makes sure that there are an adequate amount of fire exits. I stand by what I said, do what you think looks better and make sure you look after it. You'll be fine.

For what it's worth, I agree that smooth-side up looks better.

AHoy

https://www.workshop.bunnings.com.au/discussion/comment/63199#Comment_63199

Ha! I don't know about fire exits, but I do like following a good instruction manual! Sorry Jackson, I didn't mean to stifle discussion. 🙂 Your point about ramps is a good one, that's the only application grooves up should be considered. Water can't pool in the grooves obviously if there's a slope.

Kermit

You are both wrong. Everyone knows you're supposed to lay the boards on their edge. Sure, you might use more timber but you get additional height.

Jackson

https://www.workshop.bunnings.com.au/discussion/comment/1852#Comment_1852

That sounds like a great conversation starter, @Kermit!

Andy_Mann

https://www.workshop.bunnings.com.au/discussion/comment/63200#Comment_63200

You guys've need to get out more if you're getting niggly about debate etiquette, imagine being a NZer, & asking an Aussie Bunnings staff member about a deck extension.

Jackson

https://www.workshop.bunnings.com.au/discussion/comment/94100#Comment_94100

We're just having a nice, robust discussion, @Andy_Mann. I'm surprised you haven't weighed in with an opinion yet. It's not like you to sit on the fence 😉

Andy_Mann

https://www.workshop.bunnings.com.au/discussion/comment/113374#Comment_113374

@Jackson, just for you. 😉

I reckon the grooves are the dumbest idea ever, they're only there to get blokes fuss'n about it,

I propose that only grooveless decking be sold in future, & that all existing grooved stock be planed flat, before sale.

Preserve the planks with old sump oil, & sweep building sand over the top surface while the oil's still tacky for slip protection.

I hope this helps. 😋

Brad

https://www.workshop.bunnings.com.au/discussion/comment/1852#Comment_1852

While on a corporate tour of a new Uni extension aka chance to go for lunch, I did notice that some areas the cladding had moved on from the trendy batten fix look to put the outer boards on edge.

On a side note it is interesting just what you can make on a 250k 3d printer😍

Trying

https://www.workshop.bunnings.com.au/discussion/comment/124259#Comment_124259

You guys (?) are hilarious but........ my poor carpenter is sitting on the bones of what will (??) be my new beautiful EKODECK and muttering to himself in some foreign tongue. All because I asked which side will be 'up' and refused to accept 'something united'. I have to get my groove on! Cheers

stupidfish

https://www.workshop.bunnings.com.au/discussion/comment/131545#Comment_131545

Looks like there is only one way to do it!

We recommend installing the smooth side up so that the rain runs off easily helping to prolong the life of the deck and making it easier to keep clean.

https://www.bunnings.com.au/90-x-22mm-2-4m-ironwood-micropro-treated-pine-decking_p0053283

Andy_Mann

https://www.workshop.bunnings.com.au/discussion/comment/131545#Comment_131545

@Trying, after exhaustively trolling of the Bunnings site, I discovered that Ekodeck is mould and mildew resistant, which is a very good thing, but then noticed that they don't have no grooves.

Insist that your lazy, foriegn tongued carpenter route grooves on all surfaces, & pencil edges them too so you don't get splinters.

That should sort 'im out. 😄

AndyPantz89

https://www.workshop.bunnings.com.au/discussion/comment/124259#Comment_124259

Hi all. i'm new here. I do have a funny story about this topic though.
I was working in the paint and flooring area at Mitre 10 and had a customer tell me that the grooved side up on all decking timber is Kwila.
So if you have pine and install it grooved side up, then you now have Kwila! Congratulations!

But seriously though, groove side up is for air flow as well as expansion and contraction. I don't think it looks good either. However, if you like the look of it then do it however you like. Just make sure that you leave the wood long enough for it to weather before staining or oiling, and that you wash it before hand to help take away the natural tannins of the wood. Different subject but hopefully still helpful.

TheSaltyreefer

https://www.workshop.bunnings.com.au/discussion/comment/132001#Comment_132001

ribbed will be a thing of the past soon
Smooth both sides will be the norm moving forward

Jason

https://www.workshop.bunnings.com.au/discussion/comment/132001#Comment_132001

Thanks for joining in the discussion @AndyPantz89. Sounds like you have loads of experience and knowledge to share. Welcome to Workshop. We're rapt to have you join us and look forward to seeing a lot more of your posts soon. We have clever and creative members sharing inspiring projects and helpful advice every day, so we're sure you'll fit right in.

Please let me know if you ever need a hand getting the most from the site or have any feedback about how we can make Workshop more useful to you.

Thanks again,

Jason

cadsman

https://www.workshop.bunnings.com.au/discussion/comment/1843#Comment_1843

I have the best of both worlds. I installed my original modwood decking with alternate grooves down and grooves up. Just gave the deck a nice texture as well as serving the purpose. Steel joists at 400 centres, black tape to top of joists and board ends screwed with intermediate stainless steel nails, all predrilled. Still going strong after many years service. Also used ecodeck in a similar manner with ends screwed and lengths s. s. nailed, all predrilled with screws csk.

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