Topping up the sub-base - How to top up the last 3cm

[NigelH]

Hi all,

a call for help for a newbe.

I have laid and compacted my 0/32mm 15cm sub-base untill it is completely firm using all of the material that I had delivered. But, it's finished height is 3cm lower than I require.

Can I top it up with more 0/32mm hardcore and will this bed down correctly on top of my very firm already compacted sub-base.

Or is topping it up with 0/16mm hardcore a better solution.

Or is using 7cm sharp sand laying bed instead of 4cm an acceptable solution.

Looking forward to some expert advice before I order the material.

Cheers, Nigelh

[digerjones]

i would go with the 0/16mm stone, it will bed down no problem, spray with water if dry and dusty.

[lutonlagerlout]

sharp sand is NOT an acceptable laying bed
sharp sand and cement is required for patios
LLL

[NigelH]

i would go with the 0/16mm stone, it will bed down no problem, spray with water if dry and dusty.

Hi Digerjones,

thanks for the fast and clear answer. Now I feel I can continue with confidence to get this sub-base finshed and movine onto the next stage

Nigel

[NigelH]

sharp sand is NOT an acceptable laying bed
sharp sand and cement is required for patios
LLL

Hi Lutonlargerlout,

thanks for responding to my question. I forgot to make clear that I am laying block paving (20x10x8cm) to create a private driveway with an area of 50m². So I expect that sharp sand is a suitable laying bed, right?

Nigel ???

[Carberry]

sharp sand is NOT an acceptable laying bed
sharp sand and cement is required for patios
LLL

Hi Lutonlargerlout,

thanks for responding to my question. I forgot to make clear that I am laying block paving (20x10x8cm) to create a private driveway with an area of 50m². So I expect that sharp sand is a suitable laying bed, right?

Nigel ???

Yes, sharp sand is acceptable for block paving.

70mm is not acceptable though.

[NigelH]

sharp sand is NOT an acceptable laying bed
sharp sand and cement is required for patios
LLL

Hi Lutonlargerlout,

thanks for responding to my question. I forgot to make clear that I am laying block paving (20x10x8cm) to create a private driveway with an area of 50m². So I expect that sharp sand is a suitable laying bed, right?

Nigel ???

Yes, sharp sand is acceptable for block paving.

70mm is not acceptable though.

Hi Carberry,

thanks for confirming that.

My way forward is to top up the 3cm with the 0/16 hardcore giving me a sub-base total thickness of 18cm. Then I will have a sharp sand laying-bed of 4cm thickness.

That gives me something to do at the weekend.

Nigel

[lutonlagerlout]

25-40mm is ideal nige for block paving
LLL

[NigelH]

Cheers! Triple L

Nigel