I just purchased my first home, in CA, and I am in the beginning stages of my landscaping project. My question is how should I set up the irrigation in my lawn area. My lawn area is approximately a 40' by 35' rectangle (more like a square). I have already installed three additional valves dedicated to the backyard. One of the valves is for my drip system and the other two are for the lawn. My water pressure is 4 gpm. The distance from the valve to the lawn area is roughly 60'. I was planning on using mechanical sprinkler heads. I read that they are more reliable and more forgiving on water pressure fluxuations. I wanted avoid having to dig a trench and having sprinkler heads in the middle of the lawn area. Are there any suggestions you may have to help me along. Also, I was curious about the "rule of thumb" regarding how much sprinkler overlap you should have. I have spoke with people at Home Depot and they stated 50% overlap, that just seems excessive. But then again I have no idea, this is my first project of this sort. I appreciate any help you can provide.