Sloped ground foundations for garage

[Conor]

Evening all

I'm currently planning to build a metal clad and framed garage/workshop/storage shed at the back of my property. It's on a sloping site, there is about 50cm height difference between two diagonally opposite corners. The access is at the high point of the site, so the rest of the site will need to be built up varying amounts to that height. I can't put a slope in to make a suitable access to the garage for a vehicle.

I've got designs for foundation slab and pads for it if it was on a flat site. If I extend the pads down so that their height is increased by the height above ground level that it needs to be to be level and then construct a poured concrete wall to act as a retaining wall around the parts that need it. The area would then be filled and compacted with dot type 1 before the slab is poured across the top of it all.

If the retaining walls were a spade width (20cm ish) and dug down 30cm below ground level with a 15cm base of compacted dot type 1 aggregate.

Does that all sound suitable? Any suggestions? Or am I being daft...

Cheers,

Conor

(SORRY, HAD MEANT TO PUT THIS IN 'BUILDING' SECTION)

 

[Notch7]

Im not quite sure if you are doing a trench foundation with a slab, then a few courses of brickwork to put your metal frame on, or you are doing a raft foundation, poured in one go.

I suppose the conventional construction would be to dig the foundation trench, shutter up where the ground dips down (on a house, you would finish found below ground and do more courses of brick or block). Pour foundation, take out the top soil from the oversite area, lay a few courses of bricks / blocks, put in type 1 and pour slab.

 

[Conor]

Thanks Notch7.

Yes, what I was trying to describe was to dig the foundation trench, shutter up where the ground dips down, pour trench foundations and pads, take out top soil from oversite area, put in type 1 and then pour slab.

Thanks

 

[nuzuki]

Maybe throw in some reinforcing mesh for good measure. Also remember to put in some membrane between the type1 and the slab. You could blind it with sand or just add thicker membrane

 

[Conor]

Thank Nuzuki, I think a you're right that a bit of steel mesh is best to go in - I plan for a bit of A252 mesh across the whole slab. Good mention about the DPM too. Cheers

 

[nuzuki]

If you do put the mesh in raise it upto the middle of the slab using broken engineering bricks (so concrete can flow underneath and above it). Also remember to tie the reinforcing mesh to one another using wire.