footings for block shed

[StudWall]

Hello All,

I've got myself set on a project for next year of building a more permanent shed at the bottom of my garden.

i've pretty much decided on block construction, rendered and painted with a flat roof to end up something like this:

having done some research on footings for the wall and slab floor i've come up with this:

Img019

• StudWall
• 11 Nov 2016

the shed will only be used for storing valuable items such lawnmower, garden tools etc, plus maybe in the future i will turn it into a little gym


some of the pictures i've seen have the wall extending below ground level:

so im thinking of going a course or 2 of bricks deeper, anyway, can someone comment on the dimensions on my 'drawing' and whether i have missed something major.
overall dimensons will be approx 3.5m x 2.5m

Cheers

 

[John D v2.0]

My only comment would be if you're maybe going to turn in to a gym put some insulation in the floor while you can. Anything else can be added later.

 

[StudWall]

My only comment would be if you're maybe going to turn in to a gym put some insulation in the floor while you can. Anything else can be added later.

good point, doing a bit more research suggests that 150mm slab thickness is overkill for low load applications ie anything but garages and 100mm is perfectly adequate?

 

[^woody^]

Your footing is not a footing.

Your 250mm of concrete is the depth of topsoil and vegetation, so is doing nothing. You then have hardcore, which is doing even less than the ground you removed to put the hardcore in.

You foundation needs to be at a level at least 600mm below ground level, perhaps more depending on the ground conditions. And never lay a foundation on hardcore.

 

[StudWall]

Your footing is not a footing.

Your 250mm of concrete is the depth of topsoil and vegetation, so is doing nothing. You then have hardcore, which is doing even less than the ground you removed to put the hardcore in.

You foundation needs to be at a level at least 600mm below ground level, perhaps more depending on the ground conditions. And never lay a foundation on hardcore.

thanks for the advice, my sources were wrong

 

[StudWall]

how about this:

Shed2

• StudWall
• 12 Nov 2016

 

[StudWall]

I've been on the case with this project again and it seems that my designed footing of 450mm is vastly overkill!

from this blog:

http://www.beardmorebros.co.uk/website pages/how to/build_garage.htm

he built an entire garage with only 300mm depth around the edges!

 

[John D v2.0]

Well, you just need to dig down to ground that won't move enough to cause your building to fail. If you're on rock that may be 2 inches for a block of flats. If you're on clay surrounded by oak trees that might be 3m unless you're building a tent.
Just because something worked for someone else doesn't mean it will for you. Sometimes it's worth a bit more digging to save problems later.

 

[^woody^]

he built an entire garage with only 300mm depth around the edges!

That's a raft, not a strip foundation.