LeckerZuhause16 May 2016 17:46Hello everyone,
It was about time that I joined a forum focused on building and DIY projects.
I’m not a skilled tradesperson, but I’m eager to learn some simple tasks. Many things are new to me, and often I can only manage with help and advice from others.
Now, my first question is about constructing a simple small garden shed, or rather a small tool shed.
The dimensions are 1.80 meters by 2.00 meters (5.9 feet by 6.6 feet). So, definitely not a palace.
Due to a few differing opinions, I’m quite unsure.
So far, because of the small size, I have settled on a simple gravel foundation. At the corners, I plan to pour “concrete buckets/piers” and connect them to the shed with concrete beams.
Up to now, I have excavated an area sized 2.10 meters by 2.20 meters (6.9 feet by 7.2 feet) and 20 centimeters (8 inches) deep. I wanted to use a rented compactor to compact the topsoil first. Then, fill the 20 centimeters (8 inches) with sand/gravel and compact that as well. On top, I would lay simple concrete paving slabs.
My question: Is 20 centimeters (8 inches) of compacted sand/gravel sufficient? Some opinions recommended a full concrete slab foundation. However, the shed will be located in a sheltered corner. Also, there will be the concrete piers at the corners. So far, I assume this will be enough.
Has anyone had experience with such a simple gravel foundation and can maybe share some tips or advice regarding my plan?
I would be very happy to hear from you.
Best regards,
LeckerZuhause
It was about time that I joined a forum focused on building and DIY projects.
I’m not a skilled tradesperson, but I’m eager to learn some simple tasks. Many things are new to me, and often I can only manage with help and advice from others.
Now, my first question is about constructing a simple small garden shed, or rather a small tool shed.
The dimensions are 1.80 meters by 2.00 meters (5.9 feet by 6.6 feet). So, definitely not a palace.
Due to a few differing opinions, I’m quite unsure.
So far, because of the small size, I have settled on a simple gravel foundation. At the corners, I plan to pour “concrete buckets/piers” and connect them to the shed with concrete beams.
Up to now, I have excavated an area sized 2.10 meters by 2.20 meters (6.9 feet by 7.2 feet) and 20 centimeters (8 inches) deep. I wanted to use a rented compactor to compact the topsoil first. Then, fill the 20 centimeters (8 inches) with sand/gravel and compact that as well. On top, I would lay simple concrete paving slabs.
My question: Is 20 centimeters (8 inches) of compacted sand/gravel sufficient? Some opinions recommended a full concrete slab foundation. However, the shed will be located in a sheltered corner. Also, there will be the concrete piers at the corners. So far, I assume this will be enough.
Has anyone had experience with such a simple gravel foundation and can maybe share some tips or advice regarding my plan?
I would be very happy to hear from you.
Best regards,
LeckerZuhause
A depth of 80 cm (31.5 inches) is frost-proof. Otherwise, the ground will freeze and expand during winter. The consequence would be that the slabs on top would lift. If you want to do it properly, dig down 80 cm (31.5 inches), or at least close to that. The few cubic meters of gravel are not really a cost issue. The earthworks are more likely to be the main challenge.
LeckerZuhause17 May 2016 00:35Okay, thank you very much, I will definitely take your advice into account. Better to do more work now than to have to redo everything later.
If I am 80cm (31.5 inches) deep... it can't just be gravel, right? I just read that crushed stone is placed below the gravel. (For a 30cm (12 inches) deep example: 25cm (10 inches) crushed stone, 5cm (2 inches) gravel)
How should the layering be arranged for 80cm (31.5 inches)?
If I am 80cm (31.5 inches) deep... it can't just be gravel, right? I just read that crushed stone is placed below the gravel. (For a 30cm (12 inches) deep example: 25cm (10 inches) crushed stone, 5cm (2 inches) gravel)
How should the layering be arranged for 80cm (31.5 inches)?
Of course, you could fill it completely with gravel. A house also basically stands on gravel—it just needs to be well compacted. You’ll need about 1.5 times the volume of your excavated hole. So, if you dig a hole that is 2 x 2 x 1 meters, you have a 4 m³ (141 ft³) hole and will therefore need 6 m³ (212 ft³) of gravel. It’s better to order a bit too much gravel than to end up not reaching the right level and having to make adjustments later.
You can also use crushed stone first and then put gravel on top. That’s how driveways are often done, for example. You also don’t have to dig 80 cm (31 inches) deep—hardly anyone does that for driveways. But you’ll definitely notice it after a few years (just take a look at your neighbors’).
You can also use crushed stone first and then put gravel on top. That’s how driveways are often done, for example. You also don’t have to dig 80 cm (31 inches) deep—hardly anyone does that for driveways. But you’ll definitely notice it after a few years (just take a look at your neighbors’).
To be honest – hello, it’s just a garden shed.
However, since I posted a similar question here some time ago (https://www.hausbau-forum.de/threads/gartenhaeuschen-Unterbau.12680/), here is my solution:
During the house construction, I had already dug out about 20 cm (8 inches) deep for a foundation. This “pit” was then filled with gravel. Because the gravel sat there for about 1.5 years, I didn’t compact it much. Time and weather did that for us (a gardener’s saying goes: winter is the best compactor).
This year, we laid landscaping fabric on top and then added a layer of gravel (up to 5 mm (0.2 inches) stone size). On top of that, we placed 5 cm (2 inches) thick concrete paving slabs, on which the shed was built. I still need to secure the shed to some of the paving slabs with brackets, plugs, and screws so the wind can’t cause any damage. However, the wall thickness of our shed is 2.8 cm (1.1 inches). Therefore, I assume there is enough own weight so nothing will move. But better safe than sorry.
Obviously, the 20 cm (8 inches) depth is not frost-proof. However, in my opinion, it can be overdone. It’s a garden shed for storing gardening tools, a wheelbarrow, a lawnmower, and some garden furniture during winter.
Whether this will be enough or turn out to be too little – time will tell.
However, since I posted a similar question here some time ago (https://www.hausbau-forum.de/threads/gartenhaeuschen-Unterbau.12680/), here is my solution:
During the house construction, I had already dug out about 20 cm (8 inches) deep for a foundation. This “pit” was then filled with gravel. Because the gravel sat there for about 1.5 years, I didn’t compact it much. Time and weather did that for us (a gardener’s saying goes: winter is the best compactor).
This year, we laid landscaping fabric on top and then added a layer of gravel (up to 5 mm (0.2 inches) stone size). On top of that, we placed 5 cm (2 inches) thick concrete paving slabs, on which the shed was built. I still need to secure the shed to some of the paving slabs with brackets, plugs, and screws so the wind can’t cause any damage. However, the wall thickness of our shed is 2.8 cm (1.1 inches). Therefore, I assume there is enough own weight so nothing will move. But better safe than sorry.
Obviously, the 20 cm (8 inches) depth is not frost-proof. However, in my opinion, it can be overdone. It’s a garden shed for storing gardening tools, a wheelbarrow, a lawnmower, and some garden furniture during winter.
Whether this will be enough or turn out to be too little – time will tell.
G
Gartenfreund17 May 2016 09:30Hello LeckerZuhause,
I have a few questions to start with.
What material will the house be made of?
By "concrete buckets/corners," do you mean a pad foundation?
Regarding the foundation:
You could either install pad foundations not only at the corners but also in between, or use a strip foundation. In either case, you can then do without a concrete beam, as it would have a considerable weight that would need to be lifted.
If you go with pad foundations, I would do it like this:
I would rent a post hole digger. Whether a manual or motorized digger is needed depends on the soil conditions. I don’t know your soil, so I can only say that a manual digger would be sufficient for me.
You could place, for example, drainage pipes (KG pipes) in these holes that protrude slightly from the ground and then fill them with homemade mortar. After the mortar has set, place the shed on top and fasten it.
The advantage is that it can be relatively easily removed if necessary and reused for a new (possibly larger) shed or if you want to move the planned one.
Also, consider using rebar that should be inserted into the concrete.
Regarding the floor of the shed, I would not create such a raised structure. Level the soil smoothly and, if needed, compact it slightly with a hand tamper. Spread a few centimeters of sand on top and then place concrete slabs on that. Since I would only lay the slabs inside the shed and not underneath the walls, it wouldn’t matter if the slabs shift slightly in winter.
If, as suggested, you excavate a pit 0.8 m (2.6 ft) deep, you would have to move about 3 to 3.5 cubic meters (about 3 metric tons) of soil, which also needs to be disposed of. Then you need to bring in gravel, which weighs roughly 5 metric tons. So, plan for moving around 7 to 8 metric tons in total.
I took these figures from a relevant website.
This is not a small effort, especially if access to your “construction site” is difficult.
A few years ago, I moved a significantly larger amount of soil, gravel, and sand myself, so I can say it is not a huge problem to do it manually, but if it’s not necessary, it’s better to avoid it.
One more thing: if you dig a deep pit and then refill it with gravel, I would imagine the pad foundations might not be as securely anchored in the ground.
I have a few questions to start with.
What material will the house be made of?
By "concrete buckets/corners," do you mean a pad foundation?
Regarding the foundation:
You could either install pad foundations not only at the corners but also in between, or use a strip foundation. In either case, you can then do without a concrete beam, as it would have a considerable weight that would need to be lifted.
If you go with pad foundations, I would do it like this:
I would rent a post hole digger. Whether a manual or motorized digger is needed depends on the soil conditions. I don’t know your soil, so I can only say that a manual digger would be sufficient for me.
You could place, for example, drainage pipes (KG pipes) in these holes that protrude slightly from the ground and then fill them with homemade mortar. After the mortar has set, place the shed on top and fasten it.
The advantage is that it can be relatively easily removed if necessary and reused for a new (possibly larger) shed or if you want to move the planned one.
Also, consider using rebar that should be inserted into the concrete.
Regarding the floor of the shed, I would not create such a raised structure. Level the soil smoothly and, if needed, compact it slightly with a hand tamper. Spread a few centimeters of sand on top and then place concrete slabs on that. Since I would only lay the slabs inside the shed and not underneath the walls, it wouldn’t matter if the slabs shift slightly in winter.
If, as suggested, you excavate a pit 0.8 m (2.6 ft) deep, you would have to move about 3 to 3.5 cubic meters (about 3 metric tons) of soil, which also needs to be disposed of. Then you need to bring in gravel, which weighs roughly 5 metric tons. So, plan for moving around 7 to 8 metric tons in total.
I took these figures from a relevant website.
This is not a small effort, especially if access to your “construction site” is difficult.
A few years ago, I moved a significantly larger amount of soil, gravel, and sand myself, so I can say it is not a huge problem to do it manually, but if it’s not necessary, it’s better to avoid it.
One more thing: if you dig a deep pit and then refill it with gravel, I would imagine the pad foundations might not be as securely anchored in the ground.
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