Burst frozen tub drain in 2nd floor bump out

[Davej]

My kids' bathroom is located on the 2nd floor, and the tub is located over a 2nd floor bump out. See attached picture.

The tub wasn't draining after the bath. It eventually started flowing again, but it dawned on me that due to the low temps in Cleveland, OH that the drain might be frozen and the hot bath warmed it up. So I went outside and saw dripping water where the bump out is and a frozen ice sheet on the side of the house I'm assuming the p-trap is in that bump out with no warm air underneath it since thats where tub is located.

What is the proper (I'm assuming expensive) long term solution to this massive design failure by the original builder 25 years ago? I am the home's 2nd owner, been there ~four years.

 

[Cwhyu2]

I had a client many years ago with the same issue as you, our solution was to tap into a nearby heat duct and blow a small amount of heated air into the space with the trap and drain. Condition corrected.But first the trap and maybe some of the drain will need to be repaired or replaced.