Hello,
One would need to place the floor panels on some bearers to raise the floor off the ground. The bearers need to be made of treated wood otherwise the wood will rot. The size needs to be a minimum of 2 x 2 inch square, preferably 4 x 2 inch. Treated wood is often slightly green in colour and will have a rough sawn finish. You will need the lengths to be the same size as the width of your shed, 8 ft in your case. You will need to place these bearers about 18 inches apart so for a 10ft shed you will need 7 lengths, spaced equal distance apart. To level them you will need a bubble float which you can attach to anything long and flat, perhaps 3 to 4 ft long, you can attach it to anything you might have around, an old broom handle for example. Attach the level to it in level position when on something known to be level like your kitchen worktop. Alternatively there are many phone apps available, Stanley level app for example, then use your phone attached to a straight broom handle or piece of wood. If you have a timber yard get the wood ready cut to 8ft lengths. Once you have all this arrange the bearers in their position on the ground and use the level to see how much levelling is needed. You will need some packing material, your best option may be to buy some ready mixed cement which you can get in plastic tubs, and use it from the tub. Another option would be a small bag of ready mixed cement, which comes in a bag to which you add water. Other packing material would depend on how much levelling is needed, this could be off cuts of treated wood, slates or old roof tiles. If you were to use these they would need to be secured with a blob of cement to stop them moving over time. Begin your levelling from the lower side, checking with your level to see how the levels needs adjustment to the highest level. Use ready mixed cement at each end of the timber and once level add more cement to fill in any gaps. Once you have this bearer in place go to the other side and using a similar method get this one in place. One could use one of the bearers as a level with your bubble flat attached. Once all your bearers are in place and level, leave overnight for cement to harden and check again next day. Wood is going to move as it changes due to moisture content but will settle over time. Before you place your shed base on the bearers one should attach a damp proof membrane, this is available as a roll of black plastic which you fasten to the top of your bearers, this will prevent moisture from the ground spoiling the floor. Use some galvanised felt nails to attach it securely. Position your shed base on the bearers and secure with some stainless steel screws. Assemble your shed. Once assembled finish off the gap at base level where your bearers are with a piece of gravel board and paint to match shed.
Regards
