Advice needed - raised timber base for large summerhouse

[Noviceshedbuilder]

Hello everyone, any advice here would be much appreciated.

I am planning on buying a sturdy 16ft x 8ft timber summerhouse/workshop and want the simplest base for uneven ground (definately want to avoid a huge slab of concrete). I have seen adverts for eco base but this still requires level ground to go on, or some expensive adjustable support legs but was thinking more on the lines of attaching a raised timber frame to timber support posts sunk into the ground. Despite extensive googling, I haven't managed to find instructions for doing this.

Questions:
1) What size timber posts and at what spacing would you use to support a base frame for a 16 x 8ft shed?
2) How would you attach the base frame to the posts - screw in directly from side or put flat metal plates on top of the posts and rest frame on that?
3) Would metposts be suitable or would they need to be concreted in?
4) If concreted, what depth?

Thanks in advance, any advice appreciated,

 

[fencer35]

Hi
Ive done this myself
Firstly i marked out the area and dug a hole in each corner abiut 45cm deep and put half a concrete block in the bottom. I then put in a 4 x 4 tanalised post and making sure all were level and square i held them in place with some postmix.
at the highest end i put in a 8' length of 6 x2 tanalised fixed it with a couple of screws just to hold it in place. from that end i then ran 2 no 6 x 2 horitantally making sure both were level. At the other end its juat a case of putting up another joist thus making a rectangle same size as shed floor supported on posts in each corner.
Next step was to put in more 8' joists ever 2' or so use joist hangers .
when thats done go back and add extra support posts where you think they need to go.
Also go back and drill and bolt all the joist where they meet the posts. I also used a vertical piece of timber on the supports to help support the weight.
As its going to form a base .use end grain preservative on all cut edges.
This method worked very well. the shed was ground level at 1 end and 4' off the ground the other.
Its also worth mentioning that the frame joists were installed at 90 degrees to the joists on the shed floor

Hope this helps

 

[Noviceshedbuilder]

Great, thanks fencer35, really helpful, looks like this is the way to go