Question
when we first bought our house we planted a tree i think called a london maple tree. that about 15 years ago. 3 years ago we decided to expand our swimming pool area, and put a patio with paving stones beside the tree for shade. we dug up the soil, put in the crush gravel, compacted it down, then the sand, compacted it down, then the paving stones. it was perfect until recently the tree roots are lifting the stones up. what to do now. please help.  

Answer
HellO Edgar
The tree sounds like it could have been a London plane, which is rather similar to a maple tree. They do have surface roots and those roots have the kind of pressure capable of lifting paving slabs. Unfortunately it's a common problem and there is little one can do to resolve it. If you cut the roots back then the tree may die or lose half its canopy, if you leave it and re-pave the area then there is the risk that the same thing will happen all over again.

What I would suggest is to use gravel for the walking surface in that particular area, one can still walk on it but it remains flexible under the strain of the swelling tree roots. It surely makes sense to do this intead of cutting the tree down.
You could also raise the height of the slab area to allow for the tree roots to move underneath but they will probably surface in the end, unfortunately.

Hopefully that's been useful and thanks for any bonus points in advance

Regards

Jonathan Radford www.ecologicagardens.com