Our vacation home is at 7000' and we can get over 100" of snow per year. The elevated outdoor deck is plywood substrate with a water vapor barrier and 1" thick concrete tiles. When originally installed in 2008 an outdoor grout was used. The tiles are in great shape, however the grout is now crumbling due to the freeze/thaw cycle. It there any other type of elastic compound that could replace the grout that would stand up to the weather extremes?