Many customers put their lifetime brand sheds directly on the ground. Some customers don't want a permanent concrete slab or a build a wooden base. However, if your ground isn't completely flat - and we mean completely flat - you may experience problems during and after assembly. We've had a few customers call in and explain that their door doesn't shut very easily or that one corner is off the ground an inch or so. These are caused by assembling the shed on uneven ground. If you choose to put it on the ground be absolutely sure that it is flat. Also, these all come with plastic floors. The wooden base or concrete foundation instructions are showing very clearly in the owners manual included with the shed.