I have a post and beam structure built in a flood plain approximately 3 feet above grade that has a 2 inch p-trap drain line for a shower below the insulated area of the house. The drain pipe is insulated with fiberglass pipe wrap and I constructed an insulated 5 gallon bucket over the p-trap, but in this locale that gets down to 5 degrees F ,it has frozen the water in the trap. I lined the inside of the bucket with 2 inches of styro-foam insulation, is this enough or would a different type of insulation be more effective. I looked into heat wrap tape but the manufacturer recommends not for drain pipe use. At this point there isn’t any electric outlet close by.Any ideas?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story

Listeners write in about tree roots lifting concrete and ask questions about basement flooring, architectural salvage, and HVAC distribution without ductwork.
Featured Video
How to Install Cable Rail Around Wood-Post CornersHighlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
I looked into heat wrap tape but the manufacturer recommends not for drain pipe use. Any ideas?
Change the pvc trap to CI or copper, include the drop to the trap and about 2' of waste line on the outlet side of the trap.
Install heat tape
The other option is if the trap is schdl 30 or 40 pvc, change it to schedule 80 and use the heat tape.
Remove all insulation ON the trap and ABOVE the trap. Build a box around and below the trap, and insulate that. Pull the trap into the "envelope".
If there is a heating duct nearby a well-placed hole or two in the duct can provide a little extra "insurance".
Light bulb
I'd just add a light bulb.
If your feeling really fancy get a resistor and a thermostat to control it.
Think the problem with using it on a drain like a toilet is
It could melt the wax seal
it could evaporate out all the water from the trap leading to gas backflow