ᐅ Concrete slab foundation for garden shed

Created on: 31 Jul 2021 16:12
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jumbo125
Hello everyone

I have a garden shed with a footprint of 6m x 2.5m, which is 15m² (161 sq ft). Since I want to create a walking area all around it, the foundation will expand to 8m x 4.5m, which is 36m² (387 sq ft).

At first, I thought about making a full concrete slab foundation, then building an underlying frame from squared timber on top, and placing the garden shed on it. This would also secure it firmly in place.

However, I must admit that the cost of the concrete slab would already exceed the price of the garden shed, and I feel this might be overkill.

After contacting the garden shed manufacturer, they said a simple slab foundation made of paving slabs would be sufficient. However, I definitely want to anchor it securely.

So here is my planned approach:

I will create a slab foundation using paving slabs. Beneath them: 15cm (6 inches) of crushed stone, 5cm (2 inches) of gravel or grit for bedding, then the slabs on top.
At the corners, I will drill down 20cm x 80cm (8 inches x 31 inches) and make isolated pad foundations.
The squared timber frame will be anchored at the corners through the paving slabs into the pad foundations using bolt anchors. The squared timbers that form the inner frame (supporting the floor above) will only be laid on the paving slabs and not screwed down.

Now my questions:
1. Is it problematic to anchor only the corners?
2. Do I need a frost barrier (frost skirt / frost protection) around the slab foundation?

Thank you very much
Best regards, jumbo125
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Steffi33
31 Jul 2021 20:18
We embedded four strap hinges in concrete for this. We inserted a piece of reinforcing steel through the eyelet and secured everything together with concrete beneath the slab foundation. Then we screwed the hinges to the shed… here are some pictures.

Betonplatte mit Pflastersteinen und Randsteinen; Garten mit Zaun und Blumen im Vordergrund.


Gartenbaustelle: rechteckige Kiesfläche mit Betonrand, Beete und Gartenweg im Hintergrund.


Lange flache Edelstahlklinge mit drei Löchern und Markenetikett


Graue Holzbretter ruhen auf Betonblöcken über einer Betonplatte; Boden mit Kies.
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HilfeHilfe
31 Jul 2021 20:31
Complete nonsense. What’s the point of anchoring a garden shed in concrete?? It’s not going to blow away. I’ve had two garden sheds in my life, both always placed loosely on paving slabs.
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Steffi33
31 Jul 2021 20:38
HilfeHilfe schrieb:

Complete nonsense. What’s the point of concreting in a garden shed?? It won’t blow away anyway. I’ve had two garden sheds in my life. Always placed loosely on slabs.
I would have thought the same… but a coworker once found his neighbor’s dilapidated garden shed blown into his yard after a storm... Since then, I've been more cautious about it.
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motorradsilke
31 Jul 2021 21:53
jumbo125 schrieb:

Did you set the curbstones in concrete?
Yes, I already mentioned that above.
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HilfeHilfe
1 Aug 2021 07:03
Steffi33 schrieb:
I would have thought so too... but a coworker once found his neighbor’s garden shed, torn to bits, lying in his own yard after a storm... Since then, I prefer to be cautious.
Story, story, story. Never heard of that before. Maybe in the case of a wind rose.
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jumbo125
1 Aug 2021 07:07
motorradsilke schrieb:

Yes, I already wrote that above.
Great! That sounds very good. Silly question... I’ve thought about it too, but can I drill into a curb?
I would have drilled and used bolt anchors... it would break, right?