Foundation to raised decking

[Skan]

Hi,

I have a very sloping garden,approx, 2.0m horizontal to 1.0m rise. The soil is clayish.

I am considering constructing a raised decking to get some flat area. I am planning a 5.0m wide x 3.0m depth raised decking. I planned front row say, 5 no posts at 1200mm apart and 4 rows alltogether. The front row will probably have to be 1.2-1.5 above the sloping ground, with 2nd row at 1.0m above ground, 3rd row at 0.5m above ground and 4th row less than 300mm.

I have seen some good design in "Topdeck.co.uk" and very encourage with what he can do for a very sloping garden. Stillhope for my young family to have a flat garden.

I am considering using tanalised 100x100 posts with bearer on either sides of posts and joists to sit on top.

Q1) What details to the foundation?
Q2) How deep should I dig?
Q3) How big the hole should be?
Q4) Do I need any others items, basically details I think.
Q5) Concrete Mix?

Any advise or other consideration will be most welcomed.

Thank you

[steve r]

Have a look at this page decking
where all your questions are answered.

[Skan]

Thanks Steve r,

I have read the article sbut was hoping for some other expericed advise since the slope is mich greater than the one in the article. plus whether any additional supports neeeded.

Whether my design is over specified or etc

Thanks

[ABILITY]

Would up the post size to 125 x 125 or bigger if going on up to a handrail above the deck

Holes approx 450 x 450 and into ground 600. Lay some compo in base of hole, or old flag if prefer, then place post in. Prop the posts up while you build the frame and joists before concreting in place.

You must ensure the 'top' edge of deck is well anchored at the top of the slope, and the whole structure a soild item with some cross braces, do not rely on the posts to stop it from tipping forward, they only take the weight vertically.

Lots of coach bolts or drive screws to get the frame stong enough.

[Tool]

You need to Build a cantilever deck, do a search on google and you will find something on the subject i use building regs when u build decks as i tend to do commercial size projects.

It is easy once you know how to set up the job and make sure you brace it too.