I want to have a shed put in the corner of my yard (built on site by someone else). The area in question has a compound Slope with the difference in grade being about 9.5 inches. The shed will sit on a concrete slab 12' x 16'. I want to build a base for this slab so that the ground is flat. I am comfortable digging out the soil in the highest corner, building a retaining wall, compacting the ground, adding gravel (~9.5" deepest area to ~6" shallowest area) and compacting it. My question is, how big should I make the base to support the slab and shed?
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how big must the base be?
- Thread starter MizFig
- Start date
Leaflessshadetree
Well-known member
I most likely wouldn't cut down the high side/end much more than what I was replacing with for the base. On the low sides I'd want my base at least 1ft (2 would be better) wider than the slab. I'd raise in 2-3" lifts compacting each.
I wouldn't want a retaining wall anywhere near a building.
I wouldn't want a retaining wall anywhere near a building.
thank youI most likely wouldn't cut down the high side/end much more than what I was replacing with for the base. On the low sides I'd want my base at least 1ft (2 would be better) wider than the slab. I'd raise in 2-3" lifts compacting each.
I wouldn't want a retaining wall anywhere near a building.
rayra
Well-known member
Check your local codes about retaining walls and setbacks and any required clearances. I'd personally want 2' between the building and the face of the retaining wall. And you'd need the width of the footing of that wall as well, and sufficient temp slope that it doesn't just fall in on the work before the retaining wall is built.
So call it 3' back from where you plan to position the building.
You also haven't said anything about State or region or freeze depth (if any) where you are.
Or about how high or steep the slope is that you'll be cutting into. Which majorly impacts the retaining wall needs.
So call it 3' back from where you plan to position the building.
You also haven't said anything about State or region or freeze depth (if any) where you are.
Or about how high or steep the slope is that you'll be cutting into. Which majorly impacts the retaining wall needs.
Thank you. I'm in south dakota. Frost depth is 42 inches. As the retaining wall was only intended to have 9.5 inches above ground, would it be better to use something like deck footings to support the building rather than a gravel base?Check your local codes about retaining walls and setbacks and any required clearances. I'd personally want 2' between the building and the face of the retaining wall. And you'd need the width of the footing of that wall as well, and sufficient temp slope that it doesn't just fall in on the work before the retaining wall is built.
So call it 3' back from where you plan to position the building.
You also haven't said anything about State or region or freeze depth (if any) where you are.
Or about how high or steep the slope is that you'll be cutting into. Which majorly impacts the retaining wall needs.
75gmck25
Well-known member
In my area, if it's really a shed it is not a permanent building, so there are very few code requirements that apply. Make sure you know how the rules apply in your area.
Since you are in SD where pole barns are common, could you find someone to just drive 4x4s or 6x6s down into the ground to support the building? You may still want to fill under the shed to keep animals out, but the perimeter poles will provide adequate support for walls and to frame a floor.
Since you are in SD where pole barns are common, could you find someone to just drive 4x4s or 6x6s down into the ground to support the building? You may still want to fill under the shed to keep animals out, but the perimeter poles will provide adequate support for walls and to frame a floor.
DieselNut88
Well-known member
I had this same situation when building my shed. It is 10x14. I excavated the dirt, poured a footer, and layed 6" concrete block. 4 blocks high got me above grade on the deepest side.