I use my 05 cougar 302 when working (instead of financing someone elses hotel). Right now I am in Western Kansas and am expecting temps in the single digits next week along with windy conditions. I plan to make storm windows from plexiglass (thanks to this forum) shortly to solve the problems of the screen door windows on the thing. My next step is to add regular house insulation between the frame rails and close it up with some 6mm Coroplast (thanks again to this forum). My thinking is to let the insulation lay on the Coroplast, not attach it to the belly itself, allowing for airspace. I will use the insulated that is completely wrapped to help eliminate moisture problems as well as seal all the joints.
I used two layers of 1/2" styrofoam board laying on the coroplast -- but only under the area under the tanks with heaters. I surrounded my tanks with the plastic wrapped fiberglass stapled to the floor. It hangs vertically creating a wall around the tanks and seals snugly against the styrofoam boards when reattaching the coroplast. I put some 3/4" x 3 1/2" slats crosswise between the rails and screwed the coroplast using fender washers to the slats to keep the coroplast from moving while towing. I wish I had a camera that could show me the belly material as I travel. I have wondered if it is moving or being pushed up or sucked down at highway speeds.
I also sealed the the coroplast all around with gator tape to keep air from being pushed around in there when I am towing. I am going to keep a close eye on things for a while to make sure I do not get anykind of moisture build up that could cause problems. If there is I will ventilate the area when it is not below freezing by one of several means that I have not settled on yet.
BTW I hit the edge of my coroplast with a blast of air from an air hose and found that the hollows in the coroplast were full of water. I know because I squirted my wife standing on the other side of the trailer real good. It had been two months since the trailer was on the road and had since been in the garage. That is another reason I went all around the edge with tape.
I am sure I will be tweaking this system some more; --- for now I just used stuff I had lying around but I am extremely pleased with the result. With the two fifty watt tank heaters, one on the black and one on the grey, all in the one insulated area, the temps stay toasty. I drilled a hole through a cabinet floor and put one of those airconditioning thermometer probes into the cavity. It stays in the high fortys and low fiftys on a 20 degree night, and that is with no heat in the trailer. So I hurridly put separate switches on the heaters and will turn the second heater on only if it really gets close to 32 in in the open space batween the two tanks. Kind of a learn as you go thing. Actually I have already bought a 12v thermostat that will turn the heaters on when the temps get below 36 degrees.
Hope all this helps. Just wanted you to know some one is ploughing along with you.
2008 Dutchmen Kodiak 27CDSL,-94Dodg4x4Cummins- Mods:Auto switchover Honda EU3000IS gen cabeled to gen in truck.-Propride 3P hitch-Cold weather mods:Valves/tanks heated-insulated, storm windows, plumbing drains to low point. Barker 24" tongue jack
Thanks for your reply and input. Am I correct thinking that you did not do the entire bottom, but just the tank area? I am wondering if maybe a small hole in the ducting would somewhat heat the belly? Or maybe I would just be better off relying on radiant heat.
I sold a 4 season HR a few years ago then bought this one this summer, I guess I am spoiled.
I've attached some photos of portions of an Arctic Fox 29V on the production line as the basement was being plumbed and insulated. Neither portion of the job was completed on this chassis, so don't think that the insulation was only half done. I'm showing the photos so you can see that they put insulation just about everywhere.
In addition to the insulation and ducted heat from the furnace, our 29V has both 12VDC & 120VAC heating blankets on all 4 tanks.
BTW, I like AllegroSam's idea of styrofoam insulation board between the Coroplast & the bottom of the tanks.
If you've done the homework and have those key components like the Coroplast, then do the job as thoroughly as you can. I'd stuff fiberglass everywhere.
Steve & C. J. Gracie Rough Collie Bo'sun Bichon Frise Marli Lab
"For what it's worth...I built my current TH using commercially-sprayed residential foam and foil-face foam---better than ANY mass-produced RV I've ever heard of....certified R-26 walls/ceiling, R-52 floor, and surrounding FW/GW tanks the worst is about R-26...I use about 30# LPG at 0 deg.F in a week or so...have used for a couple days of sledding in N. ON/QC at camp, at -15 deg.F and it's touch and go keeping the interior at 68-70F without being plugged in, or having full sun for solar(hard to come by this far north in winter)...as long as ya' don't open things up too often, it isn't bad. 2" Foam over the windows helps a bunch! The worst part is you have to open the roof vents for a couple hours every day to get rid of moisture, and tank/fridge/HW vents will ice up eventually.
That said, +/- 0F to +20F isn't bad at all! I doubt there's many recreational rigs on the planet as good or better for winter boondocking!
Your sig says it all! I had tried to winterize my last TT---my major complaint was cold at floor and the windows!
To clarify a bit....I used Dow 1" closed-cell, foil-face up under the floor---except for above FW/GW tanks. (I don't have a black tank) Then installed tanks and all my 110/12V wiring is in sched. 40 conduit....then had commercial foam sprayed....then the plastic(that was a b-witch to fit and install as one piece!) After I siliconed/screwed the plastic against the frame members, I added 1/2" alum. angle across the front cross-member just to be safe.....I framed in & hinged a small "insulation block hatch" for my low-point drains, FW drain, and GW drain..........rather than use 110 or 12V tank heaters, I use a small fish tank bubbler, which pumps warm interior air into the FW tank.......this is my 5th winter without a freeze-up......it's -2F out there now, and my FW tank is full!
What makes this stuff so special is it's unique reflecting ability and it is moisture resistant unlike blanket insulation. In other words, you will NOT be able to seal that coroplast 100%, if you lay in the foil insulation you don't need to worry about water wicking through the blanket insulation or mold/mildew.
2013 Jayco Eagle 334RBTS Disclaimer for the daft: Don't confuse my opinion with facts.
You are getting plenty of good ideas here. Here is another thought I had. I did not pack insulation tight against the tanks but rathar created an insulated space around the tanks. The reason is I wanted to be able to put a simple heat source such as one of those heavy duty vibration proof light bulbs and heat the space and let the air circulate around the tank perhaps with the aid of a 12V computer fan. With the blanket heaters you have to be careful not to have them on when the tank is empty but you can still have a little water lurking around the valves once they are closed. I recall on the dairy farm i grew up on, just building a insulated box around water pumps and associated valving and heating it with a light bulb. A 100 watt bulb will heat R12 space the size of my tanks against some extremely cold weather, 19 below in one bad week. I only use the tank heaters for down the road and only then because I bougnt them before I engineered this project.
I am going to go back and put the bubble foil under the rest of the trailer next time I open up to do my next project.