Is freezing a problem with the Shark bite pex fittings?
Bruce
Bruce,
Freezing is an issue with any pipe/fitting.
Copper tube will swell and split.
Brass fittings will split.
Crimps will expand.
Shark bite fittings will crack.
Quest fittings will crack.
Freezing water in a contained space is a very powerful force.
Some materials are more flexible/resiliant than others, but it is far better to avoid having water freeze in a line.
I prefer and use Quest mechanical/compression fittings.

Along with Quest/Pex line, they fare a little better than copper tube, being able to expand somewhat without breaking.
The general idea though is that if damage occurs, I want to know about it right away, on the first water check of the season.
If a line or fitting is cracked, water will appear where it shouldn't be and you can make repairs.
With a loose crimp, it may not leak right away, leading you to believe all is fine, and giving you a nasty surprise when least expected.
Rob