You referring to the frame? That laminated frame is STRONG and durable. I live in Ok. where its humid to say the least. They use laminated trusses to build houses and they last FOREVER. The laminated planks under the slate are marine-grade plywood. Same deal, will last forever.
For my lack of knowledge, I will take your word for it. I always thought that plywood/fiberboard and moisture don’t mix. I guess even solid wood and moisture don’t mix well either. If I lived in Arizona or Las Vegas, I wouldn’t be concerned but I live on the gulf coast.