Understanding garden room foundations

What is the right type of foundation for my garden room?

When designing your dream garden room. You must first consider what foundations will work best. Should incorrect foundations be laid your room may suffer from long-term issues which can be costly to correct. In today’s article we discuss the most common types of garden room foundations and help you make the best choice.

Just like any other building or structure, garden rooms need the correct foundations to keep them supported. However, finding out the best foundations to use is not easy until the site has been surveyed.

Up until a few years ago. Concrete slabs remained the foundation of choice for many outbuildings like sheds and garden rooms. However, recently there has been a much wider range of options become available.

First you must understand the site.

Choosing the location of your garden room will have an impact on the types of foundation that can be used. In most cases

At Oakston Solutions we provide a free no-obligation site visit when designing and planning your garden room. This allows us to select the right foundations for your ground type.

In addition,

Concrete Slabs

One of the most common foundations for garden room are concrete slabs. Benefits include: less time to dry, protection from pests, less risk of flooding and less cost.

When considering concrete slabs you should remove all grass and vegetation as well as excavating the site to allow space for a hardcore base to be installed. In addition, you should build your base at least 50mm bigger than your garden room as a general rule of thumb.

A damp proof membrane should always be installed with concrete slabs. This can help insulate the room from below. Furthermore, some garden rooms may require steel reinforcement depending on the size and weight.

Finally they are incredibly strong and durable and are often less prone to flooding.


Plinths made from reinforced concrete are also a popular foundation. They are fairly simple to install and do not require any setting time. Moreover, they can withstand heavy pressure and movement which helps prevent damage to your room. These are often used in rooms where there is likely to be high impact footfall like home gyms.

However, you must consider that plinths can only be used on smaller projects. Anything too big, will need additional support and therefore one of the other foundations choices may offer a better solution.

Ground Screws

Ground screws are a fairly new type of foundation. However, their use is growing. They can be used on sites where digging up the ground may prove difficult or unsuitable. In addition, they can be used on undulating ground, areas with high root density or locations that tend to get wet.

The screws are often installed along with a timber base. They can be installed in one day without setting time but they do require the correct soil compaction. This allows the screws to be supported and for that reason they may not always be suitable.

Concrete Pile

Another type of garden room foundation that may be suitable are concrete piles. They are a mixture of concrete slabs and plinth foundations. They provide a solid base and can support larger buildings. Although, large building may need deeper piles. The benefit from being highly water resistant.

However, they are extremely heavy and require specific equipment making installation costly.

Getting it right with Oakston Solutions.

If you are looking for a Garden Room for you home. Our award-winning team offer a bespoke service to suit all outdoor spaces and styles. To discuss your project, email [email protected] or click here to complete our online form.