Re-laying car parking area. - Problem with tree roots

[brooks]

I have a car park, more or less rectangular and about 24 metres by 8. At one end there are three protected trees. From one end to the first tree the area is covered by large cement slabs. The rest up to the other trees is rough and once had a very thin layer of tarmac. I can see in it broken bricks and the like. The area the tree roots extend to is approximately one third of the whole. I can have blocks or tarmac laid on the other two thirds but the council tree officer has told me that any digging around the trees has to be done by hand and any damage to the roots must be professionally treated. He has said that there are restrictions on materials which can be used as a base or on the surface eg no limestone and tarmac is a non-starter.
A local firm has told me that they would have to dig down 8 inches to lay the base ( I think that is right) but the tree officer feels this could be difficult because the tree roots are very close to the surface.
I would appreciate some advice on how to proceed with this problem area and if there are other materials to consider given the possible lack of depth available. Unfortunately both the car and pedestrian entrances are in this area.

[Tony McC]

There are ways and means of creating a thin, reinforced sub-base, shielded from the tree roots and capable of providing adequate strength for either blocks or bitmac ... BUT ...

...you will need a site survey and probably the services of a civil engineer with experience in pavement construction to submit a suitable design to the local authority for approval. The depth and spread of the rootball will detrmine just what combination of geo-grids, geo-textiles, sub-base material and/or sub-base quality soils will be required. There is no 'one-size-fits-all' solution to this type of project, I'm afraid. You need to have one engineered to suit.