QUESTIONSalt Water Pools and Spalling Stone - Do you have a rule or industry standard that travertine tile " Must Not " be used on the water line area for a salt water pool?
ANSWERANSWER - There is no standard addressing stone and salt water pools. Salt Water pools are relatively new and recently more popular, so we are just now starting to see some problems with certain stones and salt water pools.
More porous stones subjected to salt water can result in the water migrating to its surface and evaporating leaving the resultant salt residue that expands and can cause spalling within the stone surface. Travertine is a more porous stone, so I would not recommend it being submerged at the waterline. Even if it is not submerged but relatively close to the pool edge, water can migrate to other areas near the pool particularly if there are voids under the stone.
Some more porous limestones could be problem too. A true granite or quartzitic sandstone might work, but there are stones sold as granite or sandstone that are not true granites or quartzitic sandstones. It is possible to install the various stones in such a way utilizing waterproof membranes and water stops that could protect the stones from the migrating salt water, but you would need to hire a qualified consultant as our company to accomplish that. Good Luck.