Sometimes your garden shed is just a temporary structure and you need to have an option of moving it easily. This is where a wooden base for your shed becomes the best option.
The base, once constructed, is fastened into the ground (i.e. grass or soft soil) with metal posts. A wooden base is not suitable for every shed and every ground condition. It is best suited to smaller sheds, as the wooden base does not have the same weight bearing capabilities as a concrete base.
A wooden base would not be suited to conditions where the ground is wet, soft or very uneven. If the ground is wet, the base will rot quickly and your shed may collapse. For wet, uneven or soft ground, concrete pillars or concrete slab are a much better option.
Waltons offers a portable shed base kit – Portabase. The base is available in a variety of sizes, from 6′ x 4′ to 10′ x 8′. The Portabase is made of pressure treated timbers . The Portabase provides inexpensive, hassle free and incredibly easy to assemble shed base solution. Just watch the video below.
A combination of brick and concrete foundations provides the best base for your garden shed. Concrete foundations ensure that your shed is stable, level, less prone to insect infestation and most important – dry.
Unfortunately, concrete foundations are also the most expensive option, they take much longer to build than a wooden base (concrete takes 7 days to cure) and they require some skill, especially with ground preparation and levelling.
Concrete foundations are ideal for any size and any type of shed, whether it is wooden, metal or plastic, providing the ground in your chosen spot is reasonably firm, drains at least moderatly well and is not prone to flooding.
You must also be reasonably sure of your chosen spot. A concrete slab, once build, cannot be moved to another location. You will have to use reasonable force to break it up and remove it or you will end up with an unsightly concrete patch on your lawn.
I have found an excellent video guide prepared by Lafarge Cement. While Lafarge DIY cement is a very good brand of cement that you can certainly use on this project, but you can use any other brand you have. Just prepare the cement mixture according to the quantities and mixing instructions on the packet and you are good to go.
If concrete is used as a base for the retaining wall, this foundation should be at least twice the width of your bricks (8″/20cm) and a minimum of 4″/10cm thick for a small shed and for larger buildings at least 10″/25cm wide and 6″/15cm thick. If you skimp and go much smaller than these dimensions you are wasting your efforts.
Concrete is also used for shed floor and needs to be at least 3″/8cm thick or it will not be strong enough. On spans over 6’/2m aim for at least 4″/10cm thick on firm ground and if the ground is soft or you intend to raise the floor level due to bad ground drainage, you need to use some aggregate.
Two rows of brick are sufficient for smaller sheds, but for larger sheds or where the surrounding ground slopes, is very soft, or drains slowly after rain, three or more rows would be better.
Building the base brick wall
Constructing and damp proofing the shed floor
Your concrete foundations are now ready and you can start assembling your shed.