Flapper wrote:
Burst pipes are due to water trapped between two slugs of ice, not the ice itself. If there was just ice and air in the lines, the ice would compress the air, which is easy to do...
You're making one huge assumption that ice expands into the least resistance area. It doesn't it expands in all directions.
As a test put some water into an open bottle this winter and see if it "expands" out of the opening leaving the glass bottle intact. Might want to put the bottle in a box to make the broken glass cleanup easier :B.