ᐅ Foundation for a Garden Shed

Created on: 3 Dec 2008 13:26
L
Lily
Hi,
I would like to have a small shed in my garden to store my lawn mower and other equipment. Do I need a foundation for it, or can I place it directly on the grass? I have no experience with this and would appreciate any helpful advice!
F
Formfleisch
7 Jul 2009 00:50
Hello Danton,

a few days have passed, and I hope you or someone else will check back here...

I removed the old floor slabs and excavated the ground down to about 20 - 25cm (8-10 inches); I couldn’t go deeper because there is extremely compacted blast furnace slag in the center of the area. Shoveling the otherwise very dusty ground was a tough job, as it was mixed with a large amount of construction debris.

Then I hired a container service to remove a cubic meter of screed dust from the attic and to deliver gravel starting at a grain size of 2cm (about 1 inch). Unfortunately, 1.5 tons of gravel sized 2-8mm (0.08-0.3 inches) were delivered instead. So, I squatted down and spent several hours breaking up the old foundation / bricks with a hammer right on site, meaning I smashed the fragments directly into the loose dust layer (5-15cm [2-6 inches] thick). Hoping this created a somewhat load-bearing and capillary-breaking base, I then poured gravel about 10cm (4 inches) thick and leveled it.

Now my questions:
1. Does this layer need to be compacted strongly, and if so, with a plate compactor? Will that even work with the round and fine-grained gravel?
2. Would it make sense to add an additional bedding layer, for example, made of crushed stone? At the moment, the slabs would protrude about 2cm (1 inch) above the surrounding ground level.
3. Should I stabilize the edges all around with curbstones? The surrounding soil seems very firm and mixed with construction debris...

If I distribute the floor pressure evenly over the beam supports, almost nothing can go wrong, right? The load from the walls and the roof is resting on the outer wall of the stone shed or on the point foundations. It would then be some kind of “floating installation.”
F
Formfleisch
7 Jul 2009 13:09
Sometimes it helps just to write things down. Before anyone seriously overthinks my amateur work:
Due to some poor initial preparations, I have decided to fully elevate the floor on supports—I will still need to pour 2-3 concrete footing pads, but I won’t have to carry a plate compactor, worry about lateral soil pressure, or fear rising damp anymore.
Otherwise, regarding the floor construction, I will follow your (Danton’s) drawing.

Thanks!
Jonathan29 Nov 2016 21:13
I am also considering building a garden shed in the spring, but since I don’t have a lot of money available, I’m thinking about which option would be the most affordable. I have already looked at some nice prefabricated garden sheds. Is there anything cheaper than buying a ready-made shed?
H
HilfeHilfe
30 Nov 2016 06:38
Define affordable? I bought a 3 x 4 meter (10 x 13 feet) garden shed as a kit for 800 euros.