In reply to Ian_Cognito:
Jumping in here. I have a c.5 year old wild country tent that has just got seriously porous, the waterproofing treatment seems to have deteriorated. Is there a possibly spray on treatment that could restore it that anyone knows of? The description of the groundsheet is: "the tough, waterproof groundsheet is made from a more durable ripstop polyester that is PU coated to give a 6000mm hydrostatic head. "
And presumably, if I have to go that way, any footproint should be narrower than the outer of the tent to stop water pooling under it, so cutting to size is going to be better than buying an approximately sized rectangle?