What preparation is needed before my concrete arrives?
For concrete bases, floors and drives, the area should be dug out to the required depth of concrete a minimum of 100mm or 4 inches is advisable and the soil should be compacted as required.
In clay based soil areas a sub-base layer of hardcore should be placed and compacted to give the concrete a solid base and prevent sinking. A thin layer of sand on top of the hardcore will provide a smooth surface to work from and make calculation of the quantity required easier as it will help to prevent variations in the depth.
If you use a layer of polythene damp proof membrane between the sub-base and concrete, it will assist in preventing your concrete from drying too quickly, and help to stop problems with rising damp on your finished project. The membrane is recommended for all habitable areas, usually not used for sheds or driveways