We bought a '04 23B 4 years ago. Our "pool of water" was deep enough to flow backwards through the condensate drain and into the camper. After determining that there was no practical fix for the sagging roof, I built a 1in thick spacer to elevate the a/c unit and remounted. Well, that lasted about a year before water started leaking into the camper again. We didn't catch it in time this go round and lost about 25 sq feet of luan ceiling on the bottom side. Jayco uses a sandwich design for the walls and ceiling for their lightweight trailers. Here is the material list for the ceiling inside to out: 1-white melamine covering 2-luan plywood 3-styrofoam insulation 4-luan plywood 5-felt backed vinyl roof covering. There is an aluminum tubing framework but I didn't care to measure the spacing. The wall/roof sections are constructed in one piece by glueing the layers together and applying a vacuum to the whole section until the glue cures. When everything is done correctly, this is a good, strong, and lightweight structure. Problems appear when when one of these layers is damaged. The luan plywood (manufactured with water soluable glue) is actually a stressed member of the structure. Luan disintegrates anywhere close to water. Disintergrated luan weakens the roof further-more sag, more water collects at 8 pounds/gallon, more sag. My solution this time is to span the outside of the roof edge to edge with a couple of 1-1/2 1/8-wall square tubing, and mount the a/c on top. The a/c mounting bolts when tightened, pulled the ceiling up. The gaps were filled in with 2x4 pressure treated pine. Two layers of fiberglas cloth patched the ceiling inside. Only a month old, and still dry, but the jury is still out.