Cement ballest sub base?? - Please need advice

[woodpecker]

Hi I am having my block paving done about 60sq mtrs. I thought type 1 scalpings were laid below the sand screed but the guys doing have dug it out and say the best way to go is with a 5" ballest and cement dry mix which will be wackered down to give me a solid base, before they put on a sand screed.

My concerns are will this be as solid a base as type 1 and although the drive does have a good slope on it will the water drain as well.

Are they doing this to save money as will the cost of type 1 scalpings be more than cement and ballest..

Please Help..

[steve wilkin]

i would have thought type 1 would be cheaper,plus sub-base should be free draining.

[woodpecker]

thanks for that but would the base be as firm as type 1

[surreyhillslandscapes.com]

Are they a paving company or builders ?

[Tony McC]

Using a hydraulically bound sub-base is done in an attempt to minimise settlement. However, if the contractors were to spend more time installing a proper flexible sub-base, and pay more attention to their screeding, edge course construction and cutting-in, there'd be a lot fewer instances of settlement.

I'm becoming increasingly concerned that bound sub-bases are being used by some so-called contractors in place of thorough construction and best practice. There are instances when a bound sub-base is justified, but these are the exception, not the rule.

If a bound sub-base is used, there are problems regarding drainage of the laying course, as discussed on this page