For all those want a 3rd, 4th, 5th floor pool. The all the nice mods you can really make a good show. I can add pictures later. It is very simple. No mods needed. All you need is empty room with a floor. Have not tried without a floor. Say you want 12 x 12 square pool. Say pool at 3rd floor and jump in pool at 4th floor. At the 4th floor were you would put the roof at, I usually do flat roof. Take the sledgehammer tool and remove 12 x 12 of roof. Next open up create a pool. Fill your hole in the roof with the pool water. You can put up walls around the pool on 3rd floor, fill to the walls which will disappear from the water. Fill in roof/floor tiles, add pool lights or other stuff. Before the pool lights got to 3rd floor and add big clear windows (3 square ones if you want). Finish putting up other walls the water took out. Leave open or in close it if you have seasons running. Add stairs or elevator to access pool, I use both with spiral staircase and fire slide pool (2 floors only). Top floor spa does the similar build for the pool. I can do pictures if needed.