Help me adopt this elderly cutie cat

Hi guys, I want to adopt an elderly cat from the local shelter. She's 14 years old. I can afford her meds and special food she needs, but there's a tiny problem so I thought people here might have an idea. She has a chronic disease and is having diarrhea instead of solid poop. And she doesn't use the litter box anymore. She used to. None of those things are a problem to me, but the flat I'm in is owed by ruthless money grabbers, and I would be heavily charged upon leaving, if the floors are ruined. I've checked all sorts of PVC floorings and they're just too expensive for me at the moment. The problem is I'm working and i live alone, and wouldn't be able to clean up straight away. The flooring is made out of wood. Anyone had a similar situation and has some kind of a cheaper option?

Any and all help is appreciated. Cat tax: the only pic of the 14 y old cutie that I have :)