Garden construction in Oak

[Gwilym]

I'm looking to do a number of projects in my garden over the coming months - raised beds, decking and a climbing frame/slide/swing thing for my daughter. We want it all to look right together and like the look of "just wood" rather than stained/treated softwood, so I want to be able to make it all (or the visible bits at least) in the same hardwood. I've found somewhere that has a good stock of Oak that they're describing as "partly air dried" with a moisture content claimed to be 30% which they say is 1/2 that of green oak. Price seems to be about 30% higher than cheap treated softwood from my local timber merchant.

If I buy inch thick boards and use if for the surface of my deck over softwood joists, how stable will it be? I'm lookinag at 180x30x2400mm boards which I would plan to place over joists spaced at, say, 400mm, screwed down with a couple of screws into each joist. A bit of 'character' as the wood dries out will be welcomed, but I won't be popular if it rapidly looks like an earthquake has hit and, come Guy Fawkes night, the whole thing is fit only for the bonfire. Will thicker wood (e.g. go to 50mm thick deck boards) be more stable, or less, or make no difference?

For the climbing frame, I'm thinking of a basic "tower" structure made with 4" square posts with pegged m/t joints holding it together and platform, railings, ladders, etc. made with similar boards to the deck, or 50mm x 30mm sections. Is this likely to stand up to the combined effects of british weaher and the toddler test for years to come, or will I have some expensive hamster bedding by this time next year?

My mates at work think I'm mad and should buy kits or get someone to do it for me. What do you guys think? I'd rather have nothing than either of those... one way the garden won't look right, the other way we'll have to sell the house and live under the deck. What do you guys think? I'm methodical and careful, have helped out with a couple of "standard" decks in the past, and can call on the help of mates to do some of the grunt work and one or two much more experienced guys for occasional advice and assistance, but this will be the biggest job I have tackled myself by far... is this a decent project for some weekends and a bit of holiday over the next few months, or do I need to be thinking more of my grandchildren than my own daughter playing on this stuff?

Sorry it's such a long post! All advice (even if you tell me to forget it!) welcome.

 

[OLD]

Green oak sleepers can be used in garden construction my local yard does 2600x200x100 for £22 + vat. can be wet to cut.

 

[jasonB]

As Old says green oak sleepers will do for the raised beds.

As for the decking, I would be tempted to rip the 180mm boards down the middle, this will reduce the risk of cupping and splitting, I have some decking which is framed in 100x75 oak and the surface is 32x100 sawn larch, you would not know they were different timbers after 6mths in all weathers (not treated)

The climbing frame in 4x4 posts would be OK, just knock the corners off with a plane to reduce the risk of splinters.

Jason

 

[Woodmagnet]

Gwilym, the best advice i can give is "go for it", we're always here to help you along if you get stuck. The satisfaction you'll get from making it yourself is one of life's greatest feelings, and the pleasure from seeing your daughter playing on your creation is immense. :wink:

 

[Slim]

Kevin, How did you get that emoticon?

 

[bob_c]

If the wood is from where i think it is ,dont go by the 30 % moisture claim,id say more like 70%,probably ok for outside though.

 

[Richard Findley]

Hi,

A couple of things I would just add to what has already been said...

Any timber left outside un-treated will turn grey (possibly silver in the case of oak) and probably split/check to some extent. Even given a coat of protective oil, it will need re-applying once or twice a year to keep it looking fresh.

Be careful in your choice of screws to hold down the decking as steel in oak combined with moisture will make black staining

I've never worked wet wood on "flat" projects but I have turned some walnut that was 40% and got soaked when working it. Obviously you won't get soaked from "flat" work but that much moisture won't do your tools much good! You'll need to keep them good and clean and give them a wipe of oil at the end of each day or you'll find them quite rusty next time you go back to them!! I'm sure others will have more experience in this field.

If you keep the above in mind then I'm sure your garden will look great by the time you're done.

Good luck :wink:

Richard

 

[Digit]

For longevity fastenings should be brass or stainless steel.

Roy.

 

[Woodmagnet]

Kevin, How did you get that emoticon?

I "borrowed" it from another forum somewhere. :lol:

 

[Gwilym]

Thanks for the help & encouragement everyone... if nobody has any definite reasons why it can't work, it time to think about some proper plans, I think... keep the thoughts coming and I'll let you know how I get along. Cheers!

 

[Gwilym]

I've just read exigetastic's post (https://www.ukworkshop.co.uk/forums/view ... hp?t=23021) about beading fence posts. It seems he's having big problems with the finish "fluffing"... I was planning to do something similar - rounding off the corners of my posts with a router, perhaps putting a v-groove in steps, etc. Am I likely to see the same issues in the green Oak?

Also, for the climbing frame I'm thinking pegged mortice & tennon joints for the main "H" frames... I've read elsewhere that it's a good idea to offset the hole in the tennon so that the peg pulls the wood together... how much are we talking here - a couple of mm? If I were to bolt throgh the m/t's instead, could I do similar?[/url]

 

[plug]

I use allot of green oak at work and often put stop chamfers on the corners, don't have a problem with it being fluffy at all in fact the greener the oak the better the finish is.
I would bolt the joints together as it is a climbing frame just for added strengh plus they can be tightened in the summer when the timber dries out, or dismantled if required.

 

[Lee Brubaker]

Richard touches briefly on untreated oak but I can tell that oak does not like water & turns BLACK. I have seen finished shelving that the lady of the house set a house plant on & of course watered it with great enthusiasm. Result... black stains. Ditto with window casings due to moisture off the glass during winter. I think I would consider an alternative hardwood.

Lee

 

[Gwilym]

Thanks again for the speedy replies.

One further question - I'm assuming I can avoid steel fixings turning the wood black if I use stainless. Is that correct? Digit mentions longevity but I'm guessing that this is a corrosion thing so stainless will be good for that too?

 

[J D Architectural Joinery]

Thanks again for the speedy replies.

One further question - I'm assuming I can avoid steel fixings turning the wood black if I use stainless. Is that correct? Digit mentions longevity but I'm guessing that this is a corrosion thing so stainless will be good for that too?

Yeah thats correct,
I believe that the furriness of the posts were down to it being the type of wood and that it would have been pressure treated.

 

[jasonB]

It's not just where it comes into contact with metal that it will turn black, any oak left outside will turn a silver grey as it weathers. Look at this deck when new and about 10months later.

If you want it to stay light then you will have to use at least air dried oak and seal it, then regularly maintain the finish which is really a loosing battle.

Jason

 

[Gwilym]

Thanks for the replies guys and the photos Jason... the weathered look is expected and fine - I'm not expecting it to match the coffee table ;-) I've only really realised quite how much the garden slopes since looking at it in terms of how much account I have to make of it in the raised beds up the sides, so I've got a big length of plastic tube arrived today to do some measuring of the levels before I can make a proper plan... will keep you posted! Cheers!