If you have bees in your roof they are most likely to be the Tree Bumblebee,
so before you call a beekeeper read this PDF document on their life cycle.
Bombus hypnorum (information on the Tree Bumblebee)
Here are 3 PDF documents showing honeybee removal from buildings in pictures so if you have the same problem you will understand what is involved.
Warren Farm Honeycomb exposed before removal.
There are some beekeepers who may be prepared to remove bees from your property depending on the difficulty. They are:
TN15 0ES 07 970 484 232 Sarah Rapley
TN15 0SB 07 740 640 686 Andrew McFadyen
DA 3 8NZ 01 732 703 746 Roy Taylor
TN15 0ER 07 871 098 989 Bret McCulloch
TN 1 2DB 07 941 375 589 Peter Hutton