I hope the pics work right. Here are a few mods I made to our Bighorn after dropping the underbelly to take care of the rain water situation.
The first pic is simply securing all the hoses and wiring that are running everywhere with all the excess lengths. I used plastic pipe straps and wire ties to secure it all. I used almost a full pack of 100 wire ties throughout the underbelly tiding up the mess of wires and hoses. When I dropped the bottom they were literally dragging on the ground.
Next I used 1 1/2inch PVC and "T"s to extend the heating duct all the way back to behind the fresh water tank and direct the heat between each holding tank. I did not glue them together, just a tight dry fit with some duct tape to insure they did not come apart. Like to keep things where I can take apart later if I decide to change something around. Such as flexible 3 inch duct and duct fan (to be installed before this winter hopefully) to draw heated air from the inside and blow it underneath, that way you can use your small electric heaters in the coach to heat the interior and the bottom and never use the propane furnace. Although the bottom never got below 50 degrees when I spent a week in the mountains this past winter with the added insulation.
The third pic is the fresh water tank drain. Notice how low it hangs. It was resting on the bottom with only three inches from the "T" sticking through the bottom. Very easy to freeze. The fourth pic shows how I added over a foot to the length of the drain and brought the "T" up and secured it to the heat duct. Not going to freeze now as long as I have heat inside the coach. And if you are wondering, yes, i rerouted all the vent and fresh water lines from the tank. All the vent lines are now above the tank with no low points to trap water and prevent venting when being filled. The supply line, even though secured to the heat duct, is still just below the bottom of the tank to provide complete drainage.
The fifth pic is the low point drains. Again the "T"s were right on the bottom making them an easy freeze point. I added a foot to each and brought the "T"s up to the top of the frame. Notice where the splice is and where the new "T"s are now. I also added a freeze alert temperature probe centered between the freshwater tank and all the plumbing. The alarm monitor is located in the bedroom.
Pics six through nine show the added insulation. I dropped the entire bottom except for the very rear. I used that as my starting point. I added R-19, 16" poly wrapped fiberglass batts. Three and a half batts in width fit perfectly across between the frame's I-Beams. I had let the foil insulation that came in the coach dry for a couple of days prior to reinstalling. I cut six inch slits in the foil insulation about every foot to let any water that might happen to enter somehow drain on to the corrugated bottom. I then spread a continuous length of ten foot width of 6 mil poly over the foil insulation, from back to where the frame steps up in the front. I placed the insulation batts on top of the poly and wrapped the excess poly over the sides of the batts, about two feet on each side. If you tape the batts together forming one large batt it works great. Then I start securing the bottom back in place. Since the batts are about eight feet long I would secure about six feet and the add another set. This is the hardest part and the slowest. Take your time and make sure you get the bottom tight. The extra thickness of the insulation makes it hard to line up the screw bolts with the original holes in the frame but I was pleased in how mine turned out. I did buy extra self tapping screws and fender washers and added several along the frame and cross members for extra support. I also added three six foot lengths of one inch angle iron across the bottom and secured them to the I-Beams with the screws to help support the bottom. I repeated this process for the front section of the underbelly also. Then cut small weep holes at the lowest points of the bottom as an added measure. Take a spray bottle of water and spray the bottom and watch where the water runs down to and drips from. Those are your low points. Make sure the coach is level first. Do not cut deep enough to penetrate the poly. Just enough to get through the corrugated bottom. You will have to make a hole where the drains come through the bottom. I used spray foam insulation to seal those when finished along with any large opening I could find in the frame or edge of the corrugation. I used Storm Blaster caulking on the small areas along with the expensive so called weather proof tape. Info: the tape is not holding (so much for weather proof). I will be removing it and using the caulk, it has held up great and is still very flexible.
Think this is enough for now. Will save the pics of the rubber boots to seal the slide cylinder holes in the frame until later. Know this is long but maybe will help someone.
