making a concrete shed base
A basic run down of the process is to dig the hole 300mm wider and longer than your shed floor, 100mm deep (providing the ground underneath is solid) and pour the concrete onto a damp proof membrane you have laid inside the base of the hole. however you build your shed base you need to make sure the ground is level over the area of the entire base.. Concrete blocks are a great way to create a level base for your shed. they can be doubled up to give a wide base, or stacked to build piers for higher clearance or uneven slopes. concrete blocks are ideal for flat or on-grade foundation support.. A concrete shed base is the strongest type of shed foundation. it is at the heavier end of the work you will do to build your shed. this article will help you to decide if you really need such a heavy duty solution or if something a bit lighter and simpler to install would work just as well.. 
making a concrete shed base
