Please forgive me - I'm DIY clueless... A spot in the middle of our landing had started sagging. The floor below is plasterboard rather than wooden floorboards, and I really want to check that it's age rather than some hideous damp / dry rot issue. The problem is it's literally in the middle and I've never taken up a carpet before unless we were getting rid of it. I'll have to lift an area including the bathroom door and a cupboard door, and I need to be able to put it back down again afterwards. I don't even know how to remove those things that keep the carpet down in the doorway - do I just pull it up? Like I said, I'm clueless about this stuff so please be gentle with me!