PEX Tubing questions

i use 200 to 250ft runs and dont put any heat to it for at least a couple months you dont want it to shrink to fast it may crack. i done my work shop 15 years ago and my basement last fall both are 30 x50 ft. you will love it ...the best move i made i would never run cement again without putting pipe under it and it dont cost much if you use it or not. i used insulation both times under it .