Hi. Eesh cold drink bottle go pop after a year. The heat expansion and contraction under deck and strain cause them to go brittle and pop.
The best bottle to use is the standard 500ml bottle HDPE 32-38g, or the one liter bottle which HAS TO BE HDPE 52-55g. High Density Polyethylene.
(THIA BOTTLE IS SAFETY APPROVED AND ACCEPTED)
A lighter bottle is made but is NOT ACCEPTABLE.
If you can't track them down PM me and I will give you details.