Foundation 3x3 garden room - composite posts/threaded bar

[philv]

We're thinking of building a garden room.

Not quite sure what to do re foundations.

I've seen on you tube people using composite posts or threaded bars concreted into holes in the ground at regular intervals to support the main joists off the ground.

Has anyone used either of these 2 nethods?

Not quire sure where to get adequate composite or threaded bars with anchor plate that also gets embedded in concrete.

Appreciate any feedback or info.

Thanks

[kiethton]

What will the room be used for?

Short of a weightlifting setup, large aquarium or anything with repeated impact shock I'd be looking at ground screws.

[OutInTheShed]

Assume that's 3m x 3m?

I built a shed using a few piers of 2 bricks side by side to support the joists.

What you need depends hugely on what you find when you start digging holes.
A mate built a field shelter, banging in posts, they went very deep before finding any strength.
Stony ground you can't get things in far enough.

Also there is your level of 'making sure'. For a simple shed, if one corner sank, you could sort it with not too much effort.
For a more serious building, you need more overkill to 'make sure'.

You can get things like Pergola supports which have a screw adjustment, enabling you to take out s bit of settlement.
But with an expensive building, the distortion of settlement may damage stuff.