Insulating pex pipes

[Spitshotz]

I have a 2008 16 ft bambi, and if the outside temp drops to under 24 degrees while camping my water line freezes at night. I run the installed heater on low and open the kitchen cabinet, but much of the line runs along the outer skin under the fridge and in a front compartment that doesn't receive any heat. So far the pipes have not been damaged, and I can get them working again with 5 minutes with a hair dryer. I'd like to prevent it from happening at all. Does anyone have experience with trying to insulate their inside pipes in critical areas, or installing heat tape on them?

[Lumatic]

I have heard pex is not as prone to freeze damage as other types, but I would like to hear from someone who knows for sure.

[AlinCal]

The pex itself expands and contracts back, One method of assembly is using an expanding tool that does just that so you can install over the fitting.
That said the fitings Im not so sure they can withstand the freeze along with any valves and pumps.
You can go to the big box and buy pipe insulation that is pre slit with sticky tape and the only obstacle being access.

[uncle_bob]

Hi

PEX and modern PEX fittings should not be damaged by freezing. Putting insulation on them does work, but it does not help a lot. If it stays cold long enough, the insulation will not do any good. Also if it gets cold enough .... same problem.

One alternative is to put heater strips on the pipe and then put insulation over that combo. Then whenever it gets cold, you turn on the heaters. The main trick is to be sure you don't get any hot spots that melt the pipe ....

Bob