Planning oak decking - anything I should be wary of?

[Benpointer]

Hi guys,

I am about to lay a decking area 7.2m x 3m alongside (and slightly projecting over) one end of a new pond we have had built in our garden.

In previous gardens I have put down a small area of sawn green oak decking and in a larger area of smooth yellow balau. The green oak was messy to lay (very heavy, very wet, tannin everywhere) and it moved and split a lot. But it did mellow to a lovely silver finish with loads of character and was fairly non-slip too. The balau was not much fun to lay - heavy, nasty dust, ruined my saw blades. It did look lovely when first layed but not so nice after a few years - black, slimy and slippery in the winter.

So, I have decided to go for oak again but this time I will use prepared air dried boards. Looking around it looks like £6 per m2 + VAT is the best price I can get. Something like this:

http://www.uk-timber.co.uk/english-oak- ... -p-21.html

Does anyone have any experience / advice re using these or similar air dried oak decking?

I am thinking I will pre-drill, countersink and face fix using stainless screws to treated c16 sw joists at 400mm centres. For the green oak decking (many years ago) I used galvanised screws (they rusted in a few years and the oak went black). For the balau I used hudden fixings between the boards which engaged in slots I had to cut in the board edges (might explain the saw blades I blunted!). The hidden fixing gave a clean look but necessitated larger gaps than I would have liked, was slow to fit, and as the boards shrunk a bit, some loosened and had to be drilled screwed and plugged

Does anyone have any views on the best fixing method for hardwood decking? Things that have worked or not worked?

Thanks in anticipation.

Steve

 

[Phil Pascoe]

Do not mix stainless and galvanize. Sometimes the only washer etc. you find the right size is galvanize and I thought, fine - the bolts are s/s it'll be fine. The reaction between the different metals will strip the galvanize, and then you have mild steel and oak.

 

[RobinBHM]

Swan brand decking screws with a square drive?

 

[Alexfn]

£6 per m2 + VAT?

 

[Benpointer]

Well spotted Alex - if only! I meant to type £36 per m2... but if anyone knows of a supplier closer to £6 I'd be interetested lol!

 

[andersonec]

Stainless did it for us but the hole in the Oak was drilled so the screw was a loose fit (the thread did not engage in the Oak) then countersink before inserting screw into softwood framing, if you can apply a clamp to hold the Oak in place and tight to the frame it will keep it firmly in place and take the pressure off the screw having to pull the wood down tight. Check the curve of the grain and try to lay them with the concave curve downwards, that way you will not get the centre of the board cupping upwards and it will stay flat.

Personally after paying that much for Oak decking I would not let it go "silver" or any other colour, when it does that it also goes rough and splinterey so that it is uncomfortable to walk on with bare feet, a treatment of some decking oil top and bottom before laying and every few years after that will preserve your investment for many years to come and keep it looking like the Oak you bought in the first place, you may as well get some rough old timber if you are going to let it go that way, if not at least give them an application of wood preserver top and bottom before fixing and every year after that.

Andy

 

[Benpointer]

Thanks Andy, good advice e laying. Do you have any photos of oak decking you have treated? I have shied away from treating and opted for the silver look on the basis that you set yourself up for an annual job for life. Also worried you'll just see the treatment not the timber.

Our house is clad in western red cedar that we left untreated - 6 years on it's a lovely mellow silver. TBH I'd have loved to have kept it the original red/pink it was when we fixed it but all the advice I had was you'll only make it look worse by applying any treatment and I am happy with the untreated result. (Appreciate cedar cladding and oak decking are very different.)

Cheers

 

[garethharvey]

I used yellow balau decking, smooth side up and fixed them with a small tool I got from Amazon. I see no reason why you couldn't use this with Oak. For me, there is nothing worse than seeing all the fixings.

This is the tool I bought: https://m.youtube.com/watch?v=B2HqHGLCSqw

 

[Benpointer]

Thanks Gareth - looks interesting. Just wonder whether the oak will split - I remember the balau I used was tough as old boots. I'll do some research.

Cheers

 

[andersonec]

Thanks Andy, good advice e laying. Do you have any photos of oak decking you have treated? I have shied away from treating and opted for the silver look on the basis that you set yourself up for an annual job for life. Also worried you'll just see the treatment not the timber.

Our house is clad in western red cedar that we left untreated - 6 years on it's a lovely mellow silver. TBH I'd have loved to have kept it the original red/pink it was when we fixed it but all the advice I had was you'll only make it look worse by applying any treatment and I am happy with the untreated result. (Appreciate cedar cladding and oak decking are very different.)

Cheers

You wont see the treatment, I can,t find any piccies of any Oak decks we laid (on my old PC) but I have put up some pics of a garden we did about eight years ago but can't remember what type of wood we used for the deck, I made a gate for my neighbour last year (10 months ago) and gave it two coats of deck oil, this is what it looks like now (photo today) and you can see the rain running off in the close up with the Oak looking nice.

You wouldn't need to do it annually, maybe in three years from now and then in another five then see how long it would be before it needed another.

As far as laying it smooth side up, be careful, it can get very slippery in winter, 'specially if is east or north facing and the stainless screws looked nice, they were the same as the ones mentioned above with the square slots. If the Oak is air dried there is very little likelihood of it splitting, green or kiln dried yes but air dried it will be living in the same atmosphere, green will buckle and split or even come off the screws, that is from experience when a client wanted green Oak to match the cladding he was having applied to his barn conversion, we had to use the same timber so he could save money, that took just a few weeks and it was a disaster.


Andy

Gate

 

[Benpointer]

Thanks Andy I agree it looks lovely. Which decking oil do you use?

 

[andersonec]

Thanks Andy I agree it looks lovely. Which decking oil do you use?

Screwfix own brand, I left the tin with the chap but I am sure it had UV protection, I am sure they are much of a muchness but stuff like Osmo may be worth researching.

My thing about fitting it flat side up is that if it is not treated it will grow a thin film of moss and that is what makes it slippery, not good if the missus is chasing you..

Andy

 

[Benpointer]

ok - I will take a look at Osmo - I was very impressed by their wood flooring oil.

Thanks

 

[Benpointer]

Thinking a bit more about fixing options (and having seen the price of good stainless screws) I was considering whether to avoid surface fixing by using stainless penny washers into biscuit jointer slots on the board edges, then screwed down from above between the boards. Could it work? Currently I am in danger of spending £200 on decent stainless face screws and having to pre-drill & countersink 800 screws :-(

 

[andersonec]

Thinking a bit more about fixing options (and having seen the price of good stainless screws) I was considering whether to avoid surface fixing by using stainless penny washers into biscuit jointer slots on the board edges, then screwed down from above between the boards. Could it work? Currently I am in danger of spending £200 on decent stainless face screws and having to pre-drill & countersink 800 screws :-(

Never seen the washer trick, presume you would have to cut the biscuit slot in situ or you would be in danger of missing the centre of the joist, I can see it working though, it would also allow some movement of the boardsand you could then use some cheaper treated deck screws.
What makes life easier is two drills, one with the counter sink bit fitted and the other with the driver bit fitted. The thing is, it may seem expensive at the start but when you do it right first time you will not regret it, do it wrong or on the cheap and rue the day when it needs repairing or the cheap screws need replacing and you can guarantee that if you start undoing the screws it will tear up a sliver of Oak or strip the head and then the air starts to turn blue.
Wait for some sunshine, fetch a bottle of wine and the time will soon pass.

Andy

 

[yetloh]

What are you intending to use for the joist underneath? Years ago I was pursuaded by the builder who was going to lay it that my yellow belau decking would be fine on pressure treated softwood joists. Big mistake. I'm now forever taking sections of it up to replace the rotted softwood with oak. Even worse, as the softwood rots it becomes like a sponge which retains waer and the rot migrates into the decking itself. Just to add to the fun, around a third of the cheap stainless screws he used to fix it snap of when attempts are made to unscrew them. I've put the new areas back with Spax stainless deckscrews but they are mega expensive and it is essential to pre-drill both the decking and the joists - I believe they do a stepped drill which does both in one go, no doubt also hideously expensive so I didn't bother.

For the oak joists I have used green oak "sleepers" from my local timber yard and ripped them down as required. These are, of course mega-heavy just to add to the challenge!

Jim

 

[Benpointer]

Jim, I'm afraid I am intending to use pressure treated softwood joists, which I already have (eek!), so slightly worried about your experience. I am surprised tbh - I'd expect them to last reasonably well. Mine will be off the ground with an inch or so of air underneath. I am going to support them on upturned M12 bolts screwed in underneath with a nut and washer to bear the weight. the bot head will sit on concrete pads.

Thinking about it now though, I can see that if you're not careful all the rain that falls will drip through the decking gaps and be slow to dry away even with clear air underneath the joists. But as I say, I already have the joists and can't afford to buy oak sleepers or joists now :-(

Two things I can do: 1. slap an extra coat of preservative on them (it can't hurt!) and 2. lay the joists so the deck boards have a slight run off along their length to one end. I wouldn't want to make that too pronounced though else it will it will look on the cock and wheelchair users (e.g. me) will be rolling off into the pond!

Has anyone else experienced issued with s/w joists? Any other suggestions? Thanks!

 

[yetloh]

I can well understand you balking at the idea of oak joists. I think I would too. Your solution should certainly help extend the life of the joists and the extra preservative sounds like a good idea, but you probably need to resign yourself to the idea that the oak will outlast them. Mine are laid on an old crazy paved york stone patio and the centre, where the air circulates best is still quite sound. In the past we have had quite a few plant pots around the edges which abut walls or fences and these have certainly exacerbated the problem. This is a tricky issue because a deck with nothing on it can look very bare. We now have fewer pots and these stand on terracotta feet or wood strips to improve air circulation which should help.

Jim