While Slide rooms should NOT leak, if you have a older Monaco Motorhome, (they came with slide toppers), having a leaking or removed slide topper will usually cause a leak inside. A operative and not sagging slide topper keeps probably 90% of the water from getting on top the slide room roof and makes less water to contac the upper slide room seal. The best way to prevent sagging is to build a 1 inch PVC tent pole system(don't glue the pieces). You slide it in the middle of the slide fabric and cause a slight "A" . This causes the water to run to the upper awning rail mount and run off and the other to run off the outer edge of the slide room. Doug