Driveway Sub base

[Don777]

Hi All

Advice needed on sub base on paving driveway at the moment is covered in gravel.Can I use gravel as sub base instead of Mot1 ?

Thanks

 

[Blagard]

No, it is not suitable, too many voids!

The use of MOT type 1 in sub-bases is because the material is graded and when compacted forms an almost solid layer. Other materials will do provided they can be compacted in a similar way.

Gravel will take into it subsoils from below and you will end up with localised sinking, especially where vehicles run over it

See http://www.pavingexpert.com/

 

[Don777]

Just about to order mot type1 12 tones for 380£ but the guy on the phone suggested crushed concrete type 1 12 tones for 250£. Is crushed concrete suitable for drive way sub base ?

 

[Blagard]

MOT type 1 can be produced in various stones. Crushed bricks and concrete are also suitable aggregates providing they have been properly processed.

However the quality of re-cycled products can vary a lot so I would want to see it before delivery. On site crushing plants can often result in dirty and excessively contaminated materials.

Once it gets tipped onto your driveway the practical options are limited!

 

[Don777]

I'm just doing some quotes for sub base another one suggested 50 crushed concrete 50 scalping . Why everyone have have different sub base suggestions ? Is scalping better aggregate the Crushed concrete?

 

[Blagard]

A lot depends on where you live!

Local supplies are usually cheaper than distant ones and so recommendations will tend to favour the decent cheap aggregates available locally. Scalpings can be perfectly OK. The only real issue is the aggregate needs to have different size stones to dust in it so that it can be consolidated into a solid layer. Even a good quality stone can sometimes arrive with too little fines in it and then blinding it with sharp sand can help close off the surface.