I love it when I get a better service than I expected and we just got exactly that from Bill Quay Joinery Service who operate in the North East. Not only did they install two new joists, they strengthened the existing ones, and managed to clear all their mess away well within the time they said. We now have a solid bathroom floor and I have absolutely no hesitation in recommending them if you need any kind of joinery or building services; we've asked them to quote for the rest of the wall coverings, tiled floor, ceiling and lighting. They don't have a website (yet!) but if you need a quality service please contact Ben on 0191 4691381.