i need to know how to confront my grandfather who is "set in his ways'

Hello curezone!

i didnt know who or where i should go for this odd advice.

I will be living in my grandfathers house, with him and my mom for the next 3 months in the spare bedroom. I have stayed in this bedroom many times before, and i get allergys from the 45 year old semi shag carpet (not joking)in the room. the rest of the house is ither hard wood floor, or 5 year old carpet. I have asked him many times in the past that i remove it and buffer the hardwood floor underneath..........everytime he says "absolutly not"! he makes it clear that that is not what he wants. and when i say that is is bad for our health, he laughs, as if im making it up. as i will be sleeping in that room for the next few months, and im afraid it will make me ill. I need to know, how i would be able to convince him in letting me remove the carpet. I have even offerd to pay for a new carpet in the room, although i prefer no carpet at all. and he says no. there has got to be some way to convince him. ?????????????????

thank you for any advice

-s