Question
the oak trees outside my house should be fine because it is raining a lot, but the bark is falling off the trees and i am trying to find if it is because the council are trying to kill them off by putting tarmac around the roots?

Answer
If you are saying that paving was put around the trees and what effect this has?? The paving (tarmac) will stop the water from getting to the roots of the trees and over time will cause them to die back or can cause the death of the tree. The paving not only stops the water but compaction of the soil will push out air pockets in the soil and also kill the roots. Not a good idea. The first signs should be the foliage starts to turn brown and fall off prematurely,  After that the bark will start to sluff off.