The Brew Cabin

Posted: **Tue Mar 22, 2005 10:03 am**

I am currently writing a spec for a car park and just wondered what depth would be best for DTp1, Base course, wearing course.

The current spec i am working from is:

300mm (after compaction) DTp1
80mm (after compaction) Base course
40mm (after compaction) Wearing course

The area will also have to take heavy vehicles (bin lorry).

Is the above quantities appropriate or not enough?

Posted: **Tue Mar 22, 2005 1:42 pm**

Depends on the CBR of the existing sub-grade and the general site conditions. A more typical spec might be ....

150-225mm improvement layer of slected crushed stone over permeable membrane
150mm Type 1 or Type 2 material at Â±20mm
150mm Type 1 material at Â± 10mm
80-100mm dense macadam binder course with 20/28mm aggregate
30-40mm 6-10mm dense macadam surface course

...this is a "typical" spec. That does not mean it is suitable for your project, as there could be site conditions that mean a different spec would be better suited.

Posted: **Tue Mar 22, 2005 1:56 pm**

The spec i have shown you is used on all our car park projects and are not adjusted to suit the site.

Posted: **Tue Mar 22, 2005 2:10 pm**

And...?

The Brew Cabin

Car park