A shed base is necessary for sheds to maintain a dry interior, prevent rotting, and keep the shed anchored down during high winds. For this, the shed needs a dry, level foundation. This can be a patio, laying a concrete foundation or paving slaps. We advise that a 100-150mm size increase is provided, bigger than your shed and that you try to lower the edges for easy rain runoff.

Take a look at our video for a visual guide to building a wooden shed base:

Choosing a shed base

Planning the shed base

  • When your shed is delivered, check that all parts are there including nails, screws, hinges and any other ironmongery.
  • Your shed will need to sit on a hard, level base, otherwise the frame will distort and the door and windows won’t open properly.

There are multiple ways of creating a shed base; firstly let us explore a concrete base.

Materials for a concrete base

  • Spade – Digging around 150mm into the ground making sure it is level. 
  • Wooden shuttering – To keep the concrete in a fixed state for setting.
  • Hardcore – 100mm filled of hardcore then concrete mixture poured on top. 
  • Concrete – Enough to create a base that is 100-150mm larger then proposed shed size.
  • Once you have followed these steps allow time for the concrete to set, using a twig to ensure that is set before further action. A concrete base is the ideal base for all types of sheds

Secondly, let us explore a garden slab base. A slab base is an easier alternative solution to a concrete base. However, these slabs still need to be placed on a
stable, flat surface.

Materials for a slab base

  • Spade – Digging around 150mm deep into the surface layer. 
  • Concrete – Filling around 100mm deep and allowing it to set. 
  • Shed slabs – Start from one corner and place slabs tightly.
  • Dropping the slabs starting from one corner will allow for a tight placement pattern, which is sufficient for a shed to stand on.

Another form of base is a timber-decking base. Decking is a quick and cheap choice of base perfect for log cabins and sheds. It also allows you to make a lovely verandah base if you make a larger base then shed. Again, the soil layer has to be flat for the decking to maintain a flat build.

Materials for a timber-decking base 

  • Spade – Dig a flat surface for a decking to be made. 
  • Timber planks – To create the decking, treat them to make them last longer. 
  • Weed Proof Membrane – Lay this underneath the decking to stop weeds growing.

Examples of shed bases that are not efficient

  • Grass – Timber sheds will rot on grass bases and you will find that the shed will eventually fall apart and may cause damage or injury to you and your items.
  • Garden slabs – Simply placing slabs on top of dirt or grass is not efficient, as it will not produce a flat and stable surface for the shed to sit on, creating an uneven distribution of weight on the shed.