4Hats

Waking up at 3 am with a BFO (blinding flash of the obvious), I realized that my plan to put a "rib" across the roof, in front of and in back of the vent would create a rectangular swimming pool with my vent as the drain, unless I could jack the roof up enough to drain water away from the vent. My preliminary jacking efforts don't even come close... maybe with a prolonged lift and some warm sun, but for now it will only raise a little. I appreciated the suggestion from Ya Baby! (put the "rib" inside) but there are also some complications with the cabinets. I'm going on a two week road trip next Monday and could hit some wet weather, so decided to put a cover over the vent as an interim action, as follows: First I built a 4" high 16 1/2" by 16 1/2" square "wall" out of good plywood. Then I built a hatch cover for "the wall" (17 x 17 roughly, with a 1" "lip" hanging down. I hinged this hatch cover to the square "wall" frame and worked out a latch for the hatch. I sprayed the whole works (except the hinges) with several layers of Plasticote, I placed this around and over the vent and attached it to the roof with butyl rubber caulk and four right angle brackets (mounted on the inside of the square and screwed into the lip of the vent flange). So... the general plan is: while parked in dry weather the hatch cover will be unlatched: when I open the vent from the inside of the rig, the vent cover will lift the hatch cover. In bad weather or while traveling or in storage I'll keep the latch on. Down the road I may take on the roof sag project, but for now I think this will keep the rainwater from overflowing my vent!

Thanks for all the thoughtful replies. I had not thought of a roof-mounted exterior support (ribs): great idea. My main concern re. the sagging roof is that water will collect on the roof and overflow the vent. I'm not so worried about head room inside. Other ideas I'm considering include: 1. Eliminating the vent entirely and putting a new vent in the front area where there is no sagging; 2. Looking into the possibility of extending the lip on the vent to about 1 1/2 to 2" high so that the "swimming pool" on the roof can't fill higher than the vent. Regarding the roof-mounted exterior support suggestions, since I neither have a shop nor fiber glas skills, I'm wondering if this might work as an alternative approach: 1, With all due caution, jack up the roof from the inside as far as I dare. 2. Go up on the roof and measure the resulting curvature... then construct two supports (ribs) to match the curvature: each support would rest on the L and R sides of the body: one would lie crosswise in front of the vent and one would lie crosswise behind the vent (possibly incorporating the roof rack idea). 3. Get two metal strips, about 2" wide and 1/8" thick (3' to 5' long, depending on the available space inside the motorhome). Drill holes through these about 2" apart along the center line. 4. Working inside the vehicle, install screws through the metal strip, up through the roof, and into the exterior roof-mounted support (caulking liberally of course). What do you think? 4Hats

Hi Linda... Thanks for the reply... I'm not liking the sound of that! Even if I raise it back up, it's likely to settle back down again? I was imagining a nice clean "pop." 4Hats

My just-purchased 18 ft. Sunrader's roof is concave / sagging. I assume that someone stood on top and accidentally popped it down. Now it collects a lot of water... enough to overflow the vent if I were to leave it uncovered in the rain! I've owned a Sunrader before and this is definitely abnormal. I'm going to try to pop it back up, but before I do, thought I'd ask if anyone has delt with this before. Thanks!