Steeltech Sheds - Concrete Bases -

Concrete Base

When you purchase your Steeltech Shed, we will discuss the concrete base you will require for your shed and what needs to be done before your shed will be delivered. We will supply you with a drawing showing your shed’s base dimensions.

While not complicated, it is vital that correct procedures are followed when installing the concrete base so as to ensure that a dry floor is achieved in your shed.

It is vital that a DPC (Damp Proof Course ) is installed correctly. 1200 Gauge Plastic sheeting , available at a hardware store is a suitable DPC for this purpose. This can only be achieved by installing the concrete base in 2 steps. …The initial base before we erect the shed and the final concrete internally , after we erect the shed. The concrete base must be done in this way to validate Steeltech Sheds guarantee.

Concrete Slab

For smaller shed units , in many cases ,the easiest way to proceed is to install a flat concrete slab of 100mm thickness slightly larger that the shed’s external dimensions. We will then erect the shed and secure it to the concrete base. Afterwards, you can lay down the DPC within the shed and pour the internal concrete floor of 50m depth. This method will not be suitable for larger units or where heavy loads will be placed on the concrete floor (eg chopping wood etc ) as the upper 50mm concrete may be prone to cracking under stress.

Concrete Strip Foundation

In the method outlined below , a strip foundation only is laid in the first concrete pour. We then erect the shed and secure it to this “Picture Frame ” strip base. Afterwards, you can lay down the DPC within the shed and pour the full internal concrete floor of 150m depth .

Base Insulation

On units with either 25mm Kingspan Panel Insulation or 40mm Composite Insulation, we recommend that you also incorporate 100mm insulation material in the concrete floor above the DPC. This will add only a small cost to the Concrete Base work, but will pay huge thermal dividends during the winter months. It will make the unit much easier to heat and ensure a higher comfort level.

This shows the shed now secured to the concrete strip foundation. Next the DPC layer will be placed on the gravel within the shed and a full depth of 150mm concrete will be poured to bring the internal finished floor up level with the sill of the door.

Concrete Base with surrounding path

Here is a nice example of a concrete base for a 5m x 3m shed. As the shed’s base was going to take up most of the space in this corner, the customer decided to fully concrete out the area so that a surrounding concrete path is now incorporated. This is phase 1 of the concrete work complete. When the shed is erected it will be securely attached to the concrete. Then a layer of DPC will be placed inside the shed and the inner floor concrete will be poured to bring the concrete floor level with the sill of the door.

Note Also (top right corner of photo ) that a power cable has already been fed thru the base so that electrics can easily be installed once the shed is erected.

Base for shed with Overhang.

Here is an example of an installed base where the shed has a 3m overhang. The concrete slab at the shed’s overhang is poured at the same time as the shed’s initial foundation strip is laid.

Once the shed is erected, the shed’s internal floor will then be poured on a DPC so that the shed’s finished floor will be 50mm higher that the concrete slab at the overhang.


Concrete Base for Home Office

As the 4m x 3m Classic home office to be installed here is clad in 40mm composite insulated sheeting, it makes sense to also have an insulated concrete floor . It is not difficult to incorporate insulation , it adds only slightly to the cost and it will ensure that the completed unit will be easy to heat during the winter months.

In this case , the initial concrete foundation is a concrete strip at the unit’s perimeter , on which the office will be erected and secured. The floor will be finished off with the installation of a DPC (returned within the unit ) , on which the insulation panels will be placed and then topped off with a layer of concrete to provide the units internal floor .

At first , it was necessary to dig out the tarmac surface and gravel underneath to allow sufficient depth for the installed concrete strip , so that the top of the concrete foundation strip will just be above the original surface level when finished.

Lengths of 6″ wood planks were cut to size to form a frame on the ground of the required size. The wood frame was positioned and levelled and its diagonal dimensions checked to ensure that it was square. 0.77 cubic meters of C 25/30 10mm concrete was used on this 4m x 3m strip foundation which has an outside dimension of 4250mm x 3170mm.

Concrete Base Drawing

Please do not assume a size for your shed as for example a 4m x 3m shed will require a base somewhat larger than 4m x 3m , as per the required bas drawing. We will supply you with a base drawing for your particular Steeltech unit. This will show you the step by step process involved and dimensions of the required base you should install. Pay particular attention to the position of the DPC and getting this correct is vital to ensuring that your concrete floor will remain dry.



If you are uncertain about concrete work, always use a qualified tradesman.

When installing a concrete base, use a minimum of 30 Newton concrete.

Concrete drying time in dry weather is approx. 3 – 4 days to harden and up to 30 days to fully dry out. This may take considerably longer during Winter months.

Confirm your Base is In

You can confirm that your base is in by completing this form here and uploading a photo of the base.

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