Garden Room Foundations

Garden Room Foundations

Garden room foundations are vital. Your garden Room could suffer from movement and internal cracks or long-term issues, such as subsidence. if you use the wrong type of foundation.

The location of your garden room will have an impact on the type of garden room foundation you require. Due to the various types of ground materials, soil conditions, and the distance from trees.

Here are the most common types of garden room foundations.

Types of Garden Room Foundations

  • Concrete Slab
  • Ground Screws
  • Concrete Pile
  • Custom foundation systems

Concrete Slab

garden room foundations ​concrete slab

Concrete slabs have been used for many years and are often the number one choice when building a garden room base.

Before installing concrete slabs, all grass or vegetation should be removed from the site and the ground excavated, which involves digging a hole where the room is to be built. The depth of the hole will depend on the size and height of your building. The hole is then filled with hardcore.

An outer timber framework is then created and a damp proof membrane (DPM) is laid down and the concrete can be poured and left to set. Once set, the timber framework can be removed and the site is ready to be built on.

Concrete slabs make for a sturdy and reliable garden room foundation system.

Ground Screws

garden room foundations ground screws

Using ground screws for building Garden room foundations is a new technique, which is growing in popularity. since it replaces the need to dig up your garden and lay down concrete. This makes it a less disruptive and time-consuming method in comparison to concrete slabs.

Ground screws are large screws that are driven into the ground using specialist equipment. Brackets are installed onto the screws to provide a base to build your timber frame for your garden room.

Ground screws are not suitable for all ground types. therefore may not always be suitable for your garden room foundations if you have loose soil in your garden.

Ground screws can be installed in one day with no setting time, meaning you can start building your frame without delay. Ground screws allow you to build on uneven ground which would otherwise need leveling. They are also an option to protect the root system of any trees which will overhang your garden room

Concrete pile foundations

garden room foundations concrete pile

Some garden office suppliers use concrete pile foundations, evenly spaced under the garden office.

The size and depth of the pile depend on the site conditions and the size of the building and the method of anchoring the structure to the piles.

They can withstand heavy loads which makes them suitable foundations for garden rooms and even larger builds.

The ground is excavated down to the solid ground, this is either dug by hand or by using a power auger which drills out the earth.

Some suppliers then insert a former tube or timber shuttering into which, hardcore is compacted, and then the concrete is poured in. These forms ensure a uniform shape, other suppliers just pour the concrete into the hole with a more rustic shape.

Depending on the choice of fixing, some suppliers will insert metalwork into the wet concrete, this has adjustable fixings which will attach to the floor frame. Other suppliers will level the pile ready for concrete beams or steel frames or in some cases, the timber floor joists to sit directly on the piles.

Custom Garden Room foundations

A few companies have developed their own garden room foundation systems, usually a hybrid of those already described.

Using high tensile threaded rods, with nuts, and washers. which are set in concrete piles. this gives an adjustable washer/plate above ground to sit the frame on


Garden Room Plans

New and improved !

Digital Plans for various sizes of Garden rooms.

  • Detailed plans
  • List of all materials
  • Material quantity and price
  • Links to each item