Decking question - building straight onto concrete base

valve90210 · 1 May 2013 at 11:20

Hi All

In the coming months I intend to build some decking at the end of my garden. At present there is a concrete base in place that the previous owners made (installed, poured, put down...or whatever the correct term would be) which is great except it is very ugly...

One side of the base is shaped round a raised planter made from old sleepers which I would like to keep in place as it is rather nice and I think will work quite nicely sort of spilling over to the decking once we have some plants in it.

Now, the planter is not hugely high which limits the height of the deck, though to be honest I also wouldn't want a high deck as my little boy (16 months) would most likely fall off it continuously!!!

I know most decks are made up of an exterior frame raised on posts with suspended joists hung between the frame however, my plan is to use 4x2 to make the frame which will be the outer frame and the joists all in one and be laid straight onto the concrete base rather than having any posts to rasie it at all as this way the height will fit in nicely with the planter and the height I want the deck.

I've tried googling for such a setup but most websites only tend to have info about constructing raised decks with post and suspended joists.

Would my plan be ok or are there any problems with doing it this way?

valve90210 · 2 May 2013 at 13:06

I've done a load of googling and still not really found an answer. I guess the main concern is drainage?

May be a bit of peace of mind I could add small 10mm raisers at points just to bring the framework slightly off the ground so air can get round?

Tesla said:
I built my decking over a sound but uneven concrete base.

I'll post some photos later this evening to give you a few ideas.

It's slightly raised off of the concrete. Some of the deck is "freestanding" on stumpy legs. Some areas I used 4" posts and punched holes through the concrete and set the posts in post-crete.

It was quite a lot of work but enjoyable and has made a huge difference to the garden.

Cheers, would be good to see some pics.

I'd like to have the whole deck 'freestanding' which I believe will be fine as the weight of the deck will hold it in place (from what I've read!!)

valve90210 · 2 May 2013 at 13:34

They look great, will need a fair few (looks like they need to be used every 400mm or so?) but I'f I've read it right you adjust themby turning the 'bolt' part which would make it pretty simple for getting the deck level (well, level but allowing a slight slope for drainage)

valve90210 · 2 May 2013 at 14:08

maccapacca said:
Yes just set the ends and wind up the intermediates till they bite.

Make sure you put a decent fall on it otherwise you'll be on your butt come autumn with the algae and or ice.

I've read something like 1:100 for the fall, that sound about right?

valve90210 · 2 May 2013 at 14:13

Lol, for some reason that tickled me!!

How best to go about ensuring I have a fall like that?

valve90210 · 3 May 2013 at 09:27

No worries mate, still very much in the planning stages so no massive rush!

valve90210 · 7 May 2013 at 10:53

How do the prices compare on the composite to the bog standard softwood decking boards? I know it'll be more expensive but can't see a price on the ecodeck site?

I guess with it being an actual manufactured artificial (essentially) product it will actually be straight unlike deck boards?

valve90210 · 7 May 2013 at 12:38

Tesla said:
Cost around £1500 in materials but is around 35 square metres. Also paid a timber yard £100 to make up and supply 18 pressure treated strings for the steps from my MDF template. All timber is treated and any exposed cuts painted with creosote.

Initially I just used some small timber scraps as legs in order to get my levels in. I then used joist off cuts as legs and bolted all the pay through. Stainless bolts, washers and nylon nuts. I probably went a bit OTT so good luck to whoever decides to rip it out one day!

First time I've built a deck but did really enjoy it. Planning to move house this year so may get to build another soon.

Forgot I hadn't replied, thanks for posting up the pics, looks really good, well done!!!

I'm hoping mine will be even less distance from the ground due to the planter that cuts into part of the area and also because I don't weant it too high for my little boy...

You mentioned bolting the joists in place, how exactly did you go about doing that?

valve90210 · 7 May 2013 at 14:29

That was for attaching the outer frame bit to the posts rights? So you could bolt right through?

I think I was having a bad brain morning, cos I was thinking how on earth did you bolt all the way through the long lengths of wood to attach them at each end but that's clearly not what you meant...

How did you attach them at the ends?

valve90210 · 7 May 2013 at 16:32

Gilly said:
I quite like the look of the drop for the shed

Surprised that people aren't securing them or raising the wood off the floor.

From the reading I've done, most people say that a deck will be heavy enough to keep itself in position on a good base.

The raising it off the floor question was my basis for the thread, I have seen people mount them directly onto say a concrete base but I figured this would probably not be too wise as it wouuld surely mean whatever was touching the floor would not be able to dry out well and would rot away fairly swiftly.