Creaking Floor

Francis

Hi all

We have a 2005 Autotrail Apache 700SE with the rear lounge. Recently I have noticed that when you stand on the floor at the rear lounge there is a creaking noise you can even hear this from outside if someone is standing on the floor. I have had a look and
can't see anything obvious also the floor doesn't feel spongey so don't think it is delamination. The van is going for its annual service after Christmas so I will get the dealer to have a look but has anyone got any idea what it might be.

Many Thanks