The tub/bases in our units are all supported by a stainless steel framework, this means that unlike some other products on the market they will not bend or move when you stand in them. This gives you a comfortable, and safe environment to shower or bathe. All our product are designed and tested to withstand occupants and water on a regular use basis. Caution should be taken to ensure that, larger items, especially the twin whirlpool baths when filled with water and two adults don’t exceed the structural capacity of its installation area. We would always recommend that you seek professional services before you buy our largest products if you are at all unsure.