Anyone who builds a new garden house must first decide on a suitable foundation. Of the various substructures, the point foundation, which saves on material and is easy to install, is very popular with those who build the garden house themselves. It is not only inexpensive, but also extremely stable, as it transfers the load to the ground at fixed concrete points.
A point foundation is a cost-effective alternative to the floor slab
How much does the foundation cost?
The material price for this foundation can be calculated very easily. For example, if you plan points measuring 25 x 25 centimeters that reach 80 centimeters into the ground, the following calculation results:
25 cm x 25 cm x 80 cm = 50,000 cm³ = 50 dm³, which corresponds to 50 liters per foundation point.
How many foundation points you ultimately have to pour depends, among other things, on the strength of the support beams used: the thicker they are, the further apart the individual points can be. One concrete point per meter is the minimum.
The required tool:
- Wheelbarrow, shovel and spade
- watering can or water hose
- cordless screwdriver
- Wrench and ratchet with nuts
- Mason cord and wooden battens
- level
- Garden and landscaping concrete or quick-set concrete
- post anchor
Plan the position of the posts
- First mark out the ground plan of the garden house with wooden battens and stretch the batter board aligned with the spirit level.
- Now use crossing cords to plan where to dig the individual foundation holes. Make them large enough, the 25 centimeters in our example above is the absolute minimum, which is only sufficient for very small houses.
- It is essential to ensure that the foundation holes are aligned at right angles, because a crooked foundation has an unfavorable effect on the statics.
- The excavation work is made easier by cardboard templates that are fixed at the desired positions with a wooden strip.
- Now lift out the individual points with a shovel and spade.
- Never fall below a minimum depth of 80 centimetres. In areas prone to frost, the foundation points should reach even deeper into the ground. This is the only way to ensure that penetrating and freezing water does not lift the construction at one point.
- A drainage layer is not mandatory, but advisable.
- Depending on the soil conditions, a supporting formwork is now also installed.
The concreting
Now mix the concrete according to the manufacturer's instructions and fill the hole. Concrete should always be mixed with the shovel so that the material is well compacted. Pour concrete to just below the edge and smooth the top.
The H-anchors are placed in the still wet material and precisely aligned with the batter board. Now let the concrete harden for at least 24 hours before you set up the arbor.
tips
Due to point foundations with post anchors, the wood has no direct contact with the ground. This ensures very good ventilation from below and prevents rotting of the wood lying on the wet subsoil. The spot foundation is also ideal for a garden shed (€24.90) on stilts.