Travertine Pavers are able to withstand cold weather conditions given that they have been properly installed and are Premium Grade.
It is highly recommended to use the sand-set installation technique detailed on our installation page (click here).
Since Travertine is an extremely porous stone, it needs room to expand and contract with the freeze/ thaw cycles. If Travertine is mud-set (mortared) in freeze/ thaw climates, you run the risk of the Travertine becoming restricted and cracking. This is why sand-setting is always recommended. To secure the border of your project, use a Flex-Bond type adhesive to hold everything in place.
Our Premium Select Travertine Pavers and Pool Coping have passed 3rd-party laboratory tests for freeze/thaw cycle performance without any cracking or deformations.
Flexbond Crack Prevention Mortar: http://amzn.to/1ov0QmD