We investigated further by pulling up the Lino in the kitchen and found plywood stuck on top of the floorboards in squares, which the builder says doesn't look good, looked dodgy. Underneath these plywood squares the floor is a wooden floor (because of the age of the house) and it turns out these are rotten. The house was treated for woodworm years before we bought it and the builder couldn't say whether it was still active but the upshot is the floor needs replacing.
The builder has quoted for 2 options, one being to concrete completely or to concrete the worst area and treat and replace the other area but the costs of this are unexpected and not included in our plans so it will be quite a hit to us. The cost is anywhere between £3.5- £5k. It needs doing though as the floor isn't suitable to carry the heavy amount of people traffic that it will need to and it's also where we are knocking through to connect the bedroom to the main house and the very act of that will affect the rotten floorboards and cause problems anyway. We have no choice.
As a result of this I'm asking; if you can help with any of these costs we hadn't known about that would be hugely appreciated, we can't bring Andy home until this is complete as it wouldn't be safe to him or the staff or the family to be walking/moving around a rotten floor.
The fundraising page is www.gofundme.com/blaggy