I have a customer who wants a flagstone patio. This is not a problem. She does not care if it is dry laid or laid on concrete pad in mortar. The only thing is that she wants to maybe put a hot tub on it in the future. My question is: What is the best method of laying patio if a hot tub will be installed later? Would the dry laid method be better to let the water drain off better? Would poured concrete be better to hold the weight of the hottub? Will sitting the hottub on top of the flagstone be a problem if they decide to put one on it? My gut feeling is that the concrete with the stone mortared in place at the correct slope (so water will drain off) is the way to go.