Hi to all fellow caravaners, I am brand new to caravaning and am just about to pick up a new Challanger 540 this weekend. I need some advice on the best type of groundsheet to use in a ultima awning. I like my feet to stay dry and Im a little confused as to whether a breathable sheet lets water or dampnes permeate the membrane, if so can anyone recommend the best type to get. I will be mainly using the van on weekends and returning it during the week back into storage. Most of the pitches on the selected site are hardstanding but there are others that are grass. Any info would be of help.