decking foundation

hello
i am building a deck wich is approx 400mm off the ground
what is the min depth of the posts the ground is full of brick clay etc, the posts are 860 betwen centres
also what is the max between the posts
many thanks chris

Do a site search Chris as there are many posts about this.

The answer isn't straightforward and I've answered something similar recently ...

Post size, beam and joist spans vary considerably based on the sizes and species of the timber and its expected loading.

There are many good sites where this is all explained in detail and tables provided to give spans.

Do a search on deck beam span or similar, you'll find loads.

I like this site as a generally good guide (it's American though so you need to use a little imagination in some areas) ...

http://www.decks.com

MW

thanks i will do