How to Build a Concrete Shed Base

Our garden sheds are extremely useful structures, providing a safe place for us to store our garden tools and materials. 

Due to the fact that the British weather often leaves a lot to be desired, a shed ensures that your mower, shovel, hedge trimmer, secateurs and other gardening equipment will not become damaged, while also keeping them securely locked away and out of the hands of intruders. 

With this in mind, it’s perhaps no surprise that building a garden shed is one of the most common DIY or domestic projects that take place each year. 

When building a shed, having a proper base installed is key. 

There are a variety of shed foundation options, including gravel and paving slabs. However, using concrete is undoubtedly the best choice. 

Durable and long-lasting, when you build a concrete shed base you can rest assured that it will stand the test of time. 

In this article, the team here at Concrete Supply UK will take a look at how to build a concrete shed base.

How to build a concrete shed base 

Before you begin building your concrete shed base, you will need to make sure you have the right equipment. 

This includes:

• Ballast, cement and water (or a ready-mix concrete mix)
• Compacted hardcore or brick rubble
• Earth rammer 
• A cement and concrete mixer 
• A tape measure
• A spirit level
• A shovel
• A rake
• A tamping board 
• A edging trowel
• A wheelbarrow 
• A plastic sheet
• A saw
• Pegs and string

Order your concrete mix

Your shed base should be at least 75mm deep, as this is considered to be the desired depth for most garden sheds.   

You will then need to work out how much concrete you need for your shed base. Use the following equation to do so – depth X width X length. This will provide you with the quantity you will need. 

Alternatively, use our concrete calculator or get in touch with Concrete Supply UK and we will make sure you always have the right quantity for your project.   

Find the right area for your shed 

Think carefully about where you want your new garden shed to be located.

Select an area that is as level as possible, building on an unlevel area will make it hard for screw holes to line up. You should also avoid swampy areas as excessive moisture may damage the shed’s structure or enter the shed and damage your tools or equipment. 

You should also not build in areas with excessive trees or foliage. This is because they can block light from entering the shed, making it dark and dingy. 

Remove vegetation 

Once you have selected where the shed is going to be built, you should spend some time removing weeds, grass and any vegetation in the area. This will help you to stop air pockets from appearing in the concrete and prevent moisture from building up and causing damage.  

Mark out the dimensions 

Then, use your tape measure, pegs and string to mark out the dimensions of your base. It is recommended to make the base around 30-40mm larger than the shed on each side.  

Always ensure the area is square in shape and not sloped in any way. Then, measure the lengths at the opposite ends. 

Dig out your base area 

Next, you should spend some time digging out the base area and excavating the ground to a depth of around six inches (or 150mm). 

Then, lay around three inches (or 75mm) of compacted hardcore brick rubble. If the area needs to be levelled further, you should use some compacted sand and use your earth rammer to compact the stone to firm up the base. 

Add a damp-proof membrane 

Lay some heavy-duty plastic sheeting over your entire sub-base, with the edges turned up inside the formwork to create a tray. If you notice any joints, make sure to overlap and tape them down. 

A damp-proof membrane will stop your concrete from drying out and prevent condensation issues.  

Pour your concrete 

Now, it’s time to pour your concrete.

Pour the concrete into the shed frame, making sure to spread it evenly and it goes into all of the corners and edges. 

We’d recommend pouring the concrete layer by layer until the frame is overflowed slightly. You can also use the tamping board to compact the wet concrete as you go.

If your pour site is in a difficult area, then we offer a pump hire service to make it easier. 

Benefits of a concrete shed base  

Installing a concrete shed base offers numerous advantages, which is why it is one of the most popular choices when it comes to a shed’s foundations. 

Some of the main benefits you can expect include:

• Durability: Concrete is one of the strongest and longest lasting materials in the building industry. Once installed, you can expect a concrete shed base to last for decades without any maintenance. It is great at withstanding severe weather conditions like rain, wind and snow.

• Enhanced stability: With a concrete shed base, your shed will have a solid, level surface which will not shift over time. This is especially important in areas with soft or uneven ground or where other materials may not be able to settle and cause the shed to be unstable.

• Load-bearing capacity: As concrete is capable of bearing significant weight without bending or breaking, it makes it the ideal choice for supporting not only the shed’s structure but also any heavy equipment that is stored within it. Whether you’re storing gardening tools, a lawnmower or any other equipment, you can rest assured that a concrete base can handle the load.

At Concrete Supply UK, we’ve spent many years ensuring all our domestic and commercial customers have the right mix for their projects. This includes supplying bespoke concrete for shed bases which our team can tailor to your exact requirements. This includes ensuring you always have the right quantity, and your project can run as smoothly as possible. For more information, contact our team today.