Will cured epoxy crack or get damaged in freezing winter temperatures?

It can, but it's rare. Once cured, epoxy is a hardened, inert plastic, and temperatures well below freezing can affect any epoxy, ours included. That is a standard limitation across all epoxy finishes, so there is always some possibility of cracking in below-freezing conditions. The UltraClear formula minimizes the risk of warping or cracking, and in most cases cold-related cracking is rare. Cold generally doesn't discolor the finish, and the cured epoxy itself is waterproof.

Prolonged exposure to below-freezing conditions can add stress to the surface, so a piece that lives outside all winter is taking on some risk. These precautions significantly improve its long-term performance:

1. Let the epoxy cure fully before it sees any cold: 72 hours above 75°F. Once fully cured, a table top can be moved through extreme cold for an hour or so without issue. 2. Make sure the bottom of the piece is fully sealed too, so it can't absorb moisture. 3. After the epoxy has cured, spray a coat of UV polyurethane over it. 4. Cover the piece when it's not in use, or bring it indoors during periods of extreme cold whenever possible.

For the build, use UltraClear Bar & Table Top Epoxy for the seal coat and the 1/8" flood coat. Fill any void or river section 1/4" or deeper with UltraClear Deep Pour Epoxy first, then top coat it with Bar & Table Top Epoxy. Guide to using both products: https://ultraclear.helpscoutdocs.com/article/859-table-top-epoxy-deep-pour-epoxy-river-table