Even for a small garden house, you can ensure the necessary stability with a cast concrete foundation. But there are also various other alternatives with slightly less effort. Depending on the nature of the soil, the structure of the terrain and the subsequent type of use, different options come into consideration, which we would like to go into in more detail here.
Which substructure is suitable for a garden house?
There are various options for a safe garden house substructure: concrete foundation slab, strip foundation, point foundation or slab foundation made of paving slabs. The choice depends on factors such as soil conditions, terrain structure and type of use.
Which foundation is suitable?
Before you decide on one of the substructures listed below, it is important to take a close look at the subsurface:
- How thick is the existing humus layer and how compacted is it?
- What types of soil are there? For example, is the soil more sandy or clayey?
- Is the terrain completely flat?
- How can you reach the construction site? Could the substructure ideally be delivered directly?
The foundation plate: quite easy to make yourself
Since the load of the garden house is distributed over a large area, this is the ideal solution if the ground does not offer good stability. The slab foundation is manufactured as follows:
- Dig a pit about forty centimeters deep, which must be about ten centimeters larger all around than the planned garden house.
- Stabilize the edges with formwork.
- Fill about halfway with gravel, which is then compacted with a vibrating plate.
- A PE film is laid on top to protect the concrete from frost damage and moisture.
- Fill with concrete in two layers, separated by a steel mesh.
- Straighten these horizontally using a puller.
The intelligent design of the strip foundation saves concrete
With this substructure, concrete is only placed under the outer walls of the garden house, but the ground must be dug at least seventy centimeters deep for the trench required for this. This allows the actual floor slab of the house to remain significantly thinner.
The point foundation
This is not that easy to plan for the layperson, because the point foundation for the garden house is usually made up of nine small individual foundations. This requires square holes with a side length of forty centimeters that must be at least eighty centimeters deep. These are boarded up and filled with concrete. An additional base plate is often dispensed with with this substructure.
The slab foundation: quick and easy to build
This consists of individual paving slabs that are laid in a gravel bed. However, this simple substructure is only suitable for smaller garden houses that do not have to withstand large loads. The construction is quite simple:
- Dig up the soil at least thirty centimeters deep.
- Place a layer of gravel about 25 centimeters thick and compact it using a vibrating plate.
- A five centimeter thick layer of gravel is placed on top to level the height.
- Lay concrete slab with joints of about five millimeters.
- These are filled with silver or quartz sand and thereby stabilized.
Long drying times are no longer necessary, the metal substructure of the garden house can be anchored directly onto the slab foundation.
Tip
No matter which substructure you choose, plan any necessary power lines and pipes for sanitary systems in advance.