Q: Can I put jacks under my slides?
A: NO never, it will mess up the slide and structure of your RV, RV body settles some and brunt of the weight is then being held by the slide, oops no give due to jack, now the slide mechanism will get messed up, seen it, helped repair it to the tune of thousands of dollars since it is NOT warranty work due to owner making the mistake and yes they can tell that is what happened.