As in buying houses and renting them out? I had one renter who did not call about a minor water leak in the laundry room. The slow dripping of water leaked down into the floor boards and the subfloor, which rotted the wood. By the time they moved out it is a wonder the washer and dryer hadn't feel through the floor. Thankfully the floor joists were still in good shape. I had to rip of the floor to the joists, replacing the floor and subfloor.
Another renter who signed a no smoking clause, smoked anyway. The burnt a hole in the carpet and the house reeked of cigarette smoke. Carpet needed replacing and the walls and ceiling cleaned and painted. Oh, and they were 3 months behind in rent.
