frozen water pipe, advice?

[arknor]

This the mortar won't set at the temperature we are seeing ATM. I'm curious to know why the pipe was full of water if it was angled down, you sure you don't have a blockage?

slow drip from the tap? maybe it formed an icicle in the pipe

 

[Ahleckz]

Is there anyone below you? (Are you in flats?)
If so, tell them!
This happened to me last winter, and seems to be happening again (I've drilled drain holes into my ceiling yesterday) this year. Water backs up from the frozen bit, comes out of the pipe and sits on my ceiling.
It almost killed me last year.