I have a cabin that is 4' off the ground and I live in the midwest. My black waterline from the well goes into the house inside a 4 1/2" piece of PVC and my toilet drains into a piece of exposed 4 1/2" PVC. What can I do to effectively insulate them without running heat tape so that the weekends that I go there, my well pump and toilet line is not frozen!
Heat tape would be a great solution but I would be hesitant since there is no one at the location during the week.
The measures taken would have to be more extreme if the location is in the northern states where temps can dip below 0 versus the lower states where it may be high 20's.
When it comes to stuff like this, I am an extremist, better safe than sorry.
This is what I would do if this were my place.
I would start by wrapping the pipes with insulation, either 3 1/2" or 5 1/2" depending how extreme the weather is.
Frame out a box using 1" x 2"s or plywood allowing enough inside clearance for the wrapped pipe.
After the box is installed around the pipe it can be wrapped using foiled insulation board with screws and washers.
Hope this helps you out