what is the best way to store camper slideout, with it in or leave it out?

Question

my concern is will it harm the slideout by leaving it extened out all the time

Answer 1

As long as it is packed away clean, well-aired and totally dry, I would leave it closed to store it. It takes up less room , and as you said its more protected that way.
Just make sure that before you want to use it again, you open and air it out the day before.

Answer 2

when we had one we always Left it in when we were storing it