Curved Garden Deck

19 Jan 2006
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West Midlands
United Kingdom

I am in the early stages of planning a fairly small (4m x 4m) ground level garden deck which I plan to build on a DIY basis.

The area where I plan to have the deck is square but do do something a little different, I would like to incorporate a sweeping curve on one side. Also, I would like to put the deck boards at 1 45 degree angle.

Is the above something I will be able to do given that this is my first deck. I am obviously confused with how you would byuild the frame to support a curve and the angle of the joists.

Can anyone perhaps recomend a good book to get any plans of something similar?

Any advice would be appreciated.

Many thanks,

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Hi Damian,

There are lots of good sites aroung the web which go into the detail you require (and have links to good books) ... Google on "deck building".

For a first deck I would avoid the curve as the framing work involved is more complex (depends on your level of carpentry skills though I guess). Laying the boards once the frame is there is no more difficult than a straight edge though ... You simply lay the boards to overhand the frame and jigsaw the "wild ends" off along the line of the curve afterwards.

45 degree deck boards are no problem though you just need to plan your frame carefully so that the distance spanned by the deck boards doesn't become excessive and lead to "bounce" ... This, of course, is solved simply by setting the joists closer together than the usual 16".

You won't be able to run a single 45 degree pattern across the deck as the longest board would be 5.66m (unless you can get boards this long) so you will have joins ... Make sure that there are joists beneath every deck board join by doubling up the joists.

Laying 45 degree patterns is far more time-consuming but the final appearance is worth the effort.

At least your deck is on the ground which does simplify things greatly ;)

Thanks for the quick response.

My carpentary skills are okay (I think) and I would be interested in having a go at a curve. The challenge I guess would be knowing what angles (and how many) I would need to enable the curve. I think the pro's must use Autocad or something.

The next issue I will have is whether I lay the frame onto concrete blocks or use posts. There is a bog standard concrete slab patio about 2 brick courses below the damp course currently. Was going to lift, dig out and hardcore the surface but need to decide the best approach to laying the frame.

Been trying to read up on all the posts on here but still a little confused at the moment.

Thanks again for your advice.

easiest way to design the frame is to mark out the shape you want on the ground with some marker paint or sand poured along the line. that way you can see the curves and work out the frame you need under it.i design mine to size on paper with a scale rule, but ialways mark them out on site as nothing is ever square and that way you can get it exactly right.

if its a concrete slab already there and its stable build the frame off of that. theres no point in breaking it up, unless you want to do work for nothing.

if you leave the slab in position you can then use blocks bedded on mortar to support the frame on.
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I'm with Thermo on the foundations provided that the patio is sound, if not, lift individual slabs where the posts will go and leave the rest ... At least you won't need a weed block ;)
I'm not sure what you mean by "knowing what angles (and how many) I would need to enable the curve" unless you are planning to approximate a curve with lots of small straight sections which is not the correct way to do it ... Though, on a ground level deck I have seen it done this way with the frame being made in box sections and the deck boards then overhanging sufficiently to enable the curve to be cut ... Downside is that the newals often end up in interesting positions.
The proper way to form a curved deck (where strength is important) is to lay the joists straight, plot the corve on the joists, cut them to length and then band the cut ends with a single curved banding joist ... This was the bit I was referring to when I mentioned carpentry skills :)
The decking boards are then laid as normal and the wild ends cut to the outline of the banding joist i.e. the desired curve.
Sorry to interject guys.

I have had enqiuries about curved decks before but am never sure quite what to use for facia boards as we usually use deck boards as facias and they dont bend as you know. What do you use?
They don't bend ... Easily ;)

They need to be heavily soaked prior to fitting and 'V' notched on the inner surface at regular intervals. They will then be flexible enough to attach starting at one end and working along the curve.

Time consuming and two person job though ... One of the main reasons people don't go for a curved and facia'd deck ... Not an easy combination :LOL:
Yeah, I did wonder about that. Not sure I would want to try it out on someone elses deck tho'. Might have a go on my own when I get round to doing it.

Recently finnished a 85 square meter hardwood deck. Not sure that method would have worked so well with that.

Can you finish with an aluminium facia which sits under the deckboards and is probably fixed to some thin ply which follws the curve?

I am sure I have seen pictures with this type of facia.


i normally take the framing up close to the edge, and use a straight fascia or an octacgon, as its never really seen, unless you have a high deck, then id be scartching me head!

Thanks for the reply again.

Going slightly off the current topic, I've been doing some further 'investigation' as to the choice of deckboards. I originally had my eye on the Yellow Balau, on the basis of its look when first installed. I believe that the colour is quickly lost with UV and hav been recommended the Southern Yellow Pine as an alternative.

Has anyone any views/recommendadtions on the choice of board. I guess they all weather unless treated on a regular basis.

Thanks again,

Weathering ain't all bad ... General tanalised softwood will weather to a silver grey if left alone and looks great IMO.
Once you start on a treatment regime, whether it be oil, stains or varnishes, you are committed ad-infinitum to re-treatment.
Leave it alone it looks great :LOL:
im a bit torn. Im with you on starting a treatment regime so you have to keep doing it, but i do like the golden yellow decent softwood decking goes in the sunlight after a few weeks, but then it does start to grey.
I also like the new golden colour but, with my own deck, the decision is a simple one ... Low maintenance, high usability and relaxation ... Silver/grey it is :LOL:
Damian30";p="349272 said:


This may be a bit late. But I put a Yellow Bilau deck in about 5 years ago. I oiled it initially and it still looks fantastic and well worth it


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