Do I need a concrete foundation for a new spa?
This really depends on the spa that you choose. Some large models require a concrete pad or a strong solid surface like a deck. Some manufacturers require their spas to sit on concrete pads or the warranty is invalidated. Hot Spring spas highly recommend a concrete pad or solid deck surface for their largest spa models, but most of their spa models can be placed on many different substrates including but not limited to a gravel pad, pavers, railroad ties or beams, hard flat ground, a concrete pad, a wooden deck, among other options. When you choose the right hot tub model for you, make sure to find out what substrates are acceptable for that model from that manufacturer.