How much does sub base compact?

[perky416]

Hi guys,

How much does a sub base compact by?
Ive read that i should lay it 25mm above my desired height as it compacts by 25mm however this seems like a lot.

Most of the area was laid using 20mm limestone with 10mm limestone on top. Some areas have 10mm limestone right down to the dirt (supplier didnt have any more 20mm so had to make do with 10mm).

Many thanks

 

[noseall]

The smaller dusty stuff compacts more then the heavier grade stuff. We just lay it to the level, compact and let the sand do the rest. The bulk stuff we get from our suppliers is both graded nicely, dry and fairly uniform.

When tipped from a lorry, the larger units roll away from the heap and separate. So I get useful with the digger, mixing up batches or saving dusty stuff for topping out.