How to build a patio slab base for a log cabin or summerhouse

You can choose from a range of base options, including a timber frame base or a patio slab base. A patio slab base provides an easy to install and simple option, suitable for most garden and building types. 

In this blog, we’ll provide step-by-step instructions on how to build a patio slab base for your log cabin or summerhouse and how to know whether this is the right option for your garden. 

Watch our video for a step-by-step guide:

What is a patio slab base?

A patio slab base is made by laying concrete paving slabs on a levelled, compacted hardcore base that matches the size of your log cabin or summerhouse. The base must match the size of your building to provide a stable and level base, but it can be made slightly bigger to provide you with a patio area that can be used for seating and to extend the outdoor living space around your garden building.

Is a patio slab base right for your garden building?

A patio slab base is the perfect base option for small and medium sized log cabins and summerhouses. They provide enough support for your garden building and are simple and easy to install when compared to pouring concrete for a concrete base. 

Other benefits of using a patio slab base include: 

• Weather resistance: Patio slabs stand up well to the wet British weather, providing you with a long-lasting and durable base for your log cabin or summerhouse. 

• Easy to install: A patio slab base is easier to install than a concrete base, avoiding the need to pour a huge volume of concrete in your garden. This is particularly beneficial if access to your garden is difficult. 

• Pest deterrent: Paving slabs sit tightly together which makes it difficult for pests to burrow underneath. Ant, wasps and other pests are unable to sneak through in comparison to raised platforms, such as a timber frame base. 

• Durable and long-lasting: Once the paving slabs have been laid, they hardly move and create a strong, stable foundation that won’t sink under the weight of your building over time.

• Multi-functional: If you create the patio slab base larger than your garden building, it also functions as a useful patio area that extends the use of your log cabin.

Building your patio slab base

Now you know what a patio slab base is and its benefits, let’s look at how you start building it.

Step one: Tools and materials

Before you start laying your base, you will need the materials. 

• Paving slabs 

• Type 1 MOT hardcore 

• Cement 

• Shovel and spade 

• Spirit level and straight edge 

• Rubber mallet 

• Compactor

Step two: Mark out the area and dig a hole

To lay a patio slab base, you usually start by marking the desired area out and digging a hole to the correct depth. This is to create enough depth for the hardcore and sand and cement mix required to secure the slabs in place. 

In our video, we start this process slightly differently. We’re building our log cabin next to an existing building on our show site. As a result, we’ve used heavy duty wooden sleepers to mark the area we’re going to install our log cabin in, so it sits slightly higher. 

Both methods will work for your log cabin or summerhouse, depending on how you want it to be positioned and whether it’s being built next to any existing structures in your garden. 

Step three: Ensure a firm, solid base

Once you’ve prepared the area by digging a hole or adding sleepers, use a compactor to ensure the base for your hardcore and sand/cement mix is solid and even.

Step four: Lay hardcore

Now you’ve compacted the prepared area to provide a level base, lay Type One MOT Hardcore throughout the entire perimeter to a depth of 80mm. It may take a few layers to get to this thickness, so we recommend compacting every layer instead of leaving it all towards the end for ease. At this stage, it doesn’t matter too much about how level the hardcore is. This is most important in the next step.

Step five: Add sand and cement mix

This mix will directly support the paving slabs on top so it’s essential to ensure this layer is level once it’s been laid. 

Mix sand and cement at a ratio of 6-1 (6 parts sand, 1 part cement). Lay this mixture on top of the hardcore, using a straight edge to level it off as you go, from one corner to another. 

Use a spirit level to check the base is level as you go along.

Step six: Add patio slabs

Once you’ve laid the sand and cement mix, perform a final check to ensure the base is level and then add your patio slabs on top. 

When the slabs have been laid, use a spirit level and a mallet to make any small adjustments required so your base is perfectly level. After waiting for the cement and sand mix to dry, it’s now time to start building your log cabin or summerhouse.

Final checks before you start building your log cabin or summerhouse

Before you start building your log cabin or summerhouse, take the time to perform a few extra checks. Making sure your base is completely ready will save you time and frustration during the build. 

Check that the base is level, it’s had enough time to dry and that it’s the right size for your building before you start. 

The base might seem like a small part of the installation, but any problems can have a huge impact on the installation process and the future longevity of your garden building. Once you’ve checked everything over, you can start building with confidence, knowing you have a strong and stable base for your log cabin or summerhouse. 

Read our next blog for the next steps of building your log cabin or summerhouse, installing a damp proof course.

If you have any questions or would like further advice on building a base for your garden building, please contact our customer service team.