I built this deck about 15 years ago out in Hertfordshire for my father.

 Recently however I noticed that the decking boards and timber frame had become quite badly rotted along one side. It's made of tanalised timber but a lifespan of 15-20 years is to be expected in the damp UK climate.

 Since most of the deck was still sound I decided on some drastic DIY...

 I ran a jigsaw slightly to one side of a joist thereby amputating the afflicted section of the deck. So it has lost about 24"/60cm in width but it's still sizeable and good for a few more years yet.

 A jigsaw gives a decent enough cut but having used one for the basic dismantling it was my intention to use a circular saw on a guide rail to give the deck a dead straight edge flush with the joist.
 At this point in the proceedings I became aware that there were a lot of bees buzzing around. I had disturbed a nest of Red Tailed Bumblebees! At first I was concerned that their underground nest might have been under the deck itself and that I'd bought it down on top of them. So I was relieved to see them coming and going from within a patch of nettles about a foot away from the footprint of the decking I'd removed.
 Understandably they were discombobulated by the seismic activity around them and bees returning from forage were no doubt disconcerted by the changed landscape so close to the entrance of the nest. I thought it best to let them settle down and will do the trimming and remove the debris another day.