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Insulation for water pipes in attic.
While pex does not ordinarily burst in the cold the water in the pipes can still freeze.
For some homes the pipes will run underneath a subfloor or at the bottom of the attic.
Water inside the pipes can still freeze.
Process for weatherizing pipes in exposed areas of the home such as the garage basement and exterior walls.
It is important to insulate pex pipe in an attic particularly in cold weather areas.
Otherwise a cold water line run a long distance through a hot attic can take several.
If you have used a 14 inch flashing around the vent pipe it should be easy to insulate to this level while still maintaining a 4 inch gap at the top.
The drywall ceiling was insulated and the pipe was separately insulated even further as i say 360 degrees.
For other homes the pipes might be located in the walls or the roof rafters.
Ref insulate cold water pipes thoughtfully the frozen pipe was in the attic of the garage.