TT ability to withstand the cold.

Earlier this year I had my trailer in -10°F nights and 8°F days. My trailer has a heated underbelly and it did ok. The furnace ran pretty much all of the time and we had a space heater going on the inside. The only thing that froze was the low points because they hang below the belly and the regulator froze once.

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Having just had our underbelly coroplast off, the design of "heated underbellies" is ridiculous besides being very inefficient. There's a 2" layer of batt insulation under the tanks which gets squished and thus reduces it's R-value plus the insulation blocks air flow. The only way "heated" air gets from the front of the TT to the rear is via a small gap between the tanks and I-beams. It would be interesting to know what manufacturers do a better job, if at all, like maybe Northwoods products, OutdoorsRV, Nash & Arctic Fox. (These also have thicker walls.)

I also know they do a poor job of insulating ceiling cavities in TTs. I've seen the ceiling cavity in 3 TTs we've owned and it's sad what they do. Our current TT has an arched ceiling and because the joists taper down at the outer perimeter, there's no insulation for up to 6" in from the exterior wall. Lot's of voids too.

RVs in general aren't designed very well for cold weather. The exterior walls and ceiling assemblies have an exterior skin which is the moisture barrier/retarder and is opposite to buildings. Warm moisture-laden air migrates to the exterior surfaces and condenses on the interior side which can lead to mold, rot & delam. It's important to remove the moisture-laden air by cracking open some vents and windows or using a dehumidifier. Venting air out of course means you're losing heat and the furnace will need to run more.

Huntindog wrote:
My present TT came with the heated underbelly. Had a cold snap shortly after getting it. We lost flowing water at 5 degrees. This was with the furnace running non stop with the roof vents wide open to keep us from baking.

Here is a link to the thread about the mods I did to improve it:Cold weather mods

Basement water lines are the first to freeze. Running heat trace on them solves that problem.

My waste tanks hang out in the open. But the fresh water system is all inside. I've camped in the snow a few times and had no issues (other than using lots of propane for the heater, and gas for the generator). The dump valves were frozen, so I just waited till I got home to dump. If I were staying long term i'd have a poopsikle problem.

It's my understanding that most RV Manufacturers believe that their "4 Season" RV's means you can use them in the Northern United States and most of Canada during May, June, July and August.

If it is supposed to freeze during the night, disconnect the outside hose and drain it so no ice forms in it. In the morning reconnect it. You’ll be fine. During the day if you are concerned about freezing leave the taps drippings like at home.

My present TT is a “4 Season”; my previous TT was not. Using the above protocol I have never had a problem in either late February or in early October, the outside limits of our camping schedule.

RSD559 wrote:
I wasn't even thinking about the cold temperatures at night until our water stopped working. Everything in the trailer was fine, but the hose from the spigot had frozen solid.

Some campgrounds no longer rely on signs posted about disconnecting hoses in freezing weather, but instead shut off and padlock the hydrants.

You have to look under there and see what 4 season means.
Plenty of people in places like Alaska and Wyoming live in RVs year around. They figure out ways to make everything work in extreme temperatures.