Advice on deck design

Donnchadh

Hey, I'm looking for some advice for a new deck I plan to build in my back garden. The basic layout is attached. One end will be fixed to a concrete wall and the other side supported on 3 concrete piers that I plan to build. What depth should the piers be?

The base frame will be built out of 2x6 as shown. Do you think that the design is correct so that it doesn't end up like a trampoline? Any suggestions for improvements to the design would be great.

alphanumeric

Is the deck fitting into a set space? It could save you some work if you reduced the length to 192", a single decking board would span from one end to the other then.

Donnchadh

It's that size to fit in a specific area but I suppose I could reduce it to 192 and fill the gap with something. It would save a lot of cutting

Do you think I should use 2x6 or 2x8 maybe with 14in centres? I would prefer the height to be minimal as there is a wall close by into a neighbours garden and I don't want to be overlooking them
Are the piers in the best location? Are they the correct size?

Skrynesaver

Re Pier depth: Depends on the soil. However in my own experience going down ~8ins and filling with concrete works. I then use a bolt on post holder to take an upright to support a joist running from pier to pier the length of the deck.

that is an upright on each pier
which together support a beam the length of the deck which the 6x2s are attached to.

alphanumeric

I built my own deck and a few for friends and am far from an expert but they havent fallen apart as yet! I never went to the rounds of sinking piers. The deck is attached to the house wall and leveled off by placing timber underneath to fill the gaps where needed. I then dropped the spacers down to ground level at random places and to date it hasnt sunk anywhere. The deck was placed over a firm lawn so this worked out for me.

Your drawing is impressive, it will turn out well going by the detail you are going too.

tipperary

Hi

I agree your drawing looks impressive! I've just finished (well almost) building a deck myself. One thing I do remember is that generally the maximum span is about 6' between supports. Can't find it now but I did find some guidance from some UK crowd who manufacture decking. The 6' spacing on the joists can just rest on beams, which again need to be supported at about 6' spacings.

That said a lot of these guidelines can be very conservative so you will probably get away fine with using longer spans between supports. If the height isn't too much you could just use a few concrete blocks or paving slabs to provide the extra support.

Another thing to note is the fall in the boards. The fall needs to be in the direction of the grooves in the boards, so in your drawings the fall will be parallel to the wall.

Hope that helps

flutered

look up cnet.com they have quite a few bits of software on gardening, which will give you all the info you need + is all either freeware or free to try. a lot of professionals that i know use the stuff from there.

Donnchadh

Thanks for all the replies. Does anyone know what the max span for joists made from 2x 4 is? I'm building this close to a boundary wall and so I want to minimise the height so that I'm not overlooking the neighbours.

It's also being built over an old crumbling patio, which would probably subside over time with the weight of a deck, hence why I am building it on piers.