What's a Compacted Sub Base?

Subgrade—this is the native soil (or improved soil), usually compacted. Subbase—this is a layer of gravel on top of the subgrade. Base (or base course)—this is the layer of material on top of the subbase and directly under the slab.

Does sub-base need to be compacted?

It's essential that any flexible sub-base is laid and compacted properly, and compaction should be done in at least two layers using the correct equipment. A vibrating plate compactor may be suitable for patios and paths, but a much heavier-duty vibrating roller will be required for a driveway.

What is compacted subgrade?

A subgrade is made up of native soil that has been compacted to withstand the loads above it. It is a layer required in many structures such as pavements and slabs, although it needs to have certain characteristics.