Bathroom I did a few years ago, got a call recently in Jan that there was a slight leak from the w/c which is a back to wall pan and cistern, pulled it out and redid every joint, all was ok. The old chap rang me again a few weeks ago while I was busy to say it was leaking, I thought how is that possible and all i can do is pull it again and do exactly the same again. Pulled it this morning and was amazed to see the flexi pan connector looking as if it had been chewed and all under the pan was a pile of dead leaves, could a rat have done this by coming up the soil pipe, this is on the ground floor, iv'e never had this before.
They are cunning beasts! You need anti-rodent trap: http://www.drainageonline.co.uk/Pan-Connectors/Anti-Rodent-Barrier.htm Also need to inform local authority and water company
Everything back in and boxed up now, what can the customer put in the loo to try and prevent this happening again i.e chemical such as strong bleach would this do any good or would the rat just end up white lol.
repipe the soil in rigid pipe , always a potential problem with flexis I dont think thats going to stop a rat biting his nipper.