SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have read that the main line that feeds the manifolds should be at leat 18" deep. The deeper the better actually especially in colder climate areas. Actually, any line that has contant pressure is considered a main. Manifolds are not going to sit that deep in the ground so how do I protect the main feeding the manifold? Or do I place a shutoff vavle in the basement on the main that feeds the manifolds and turn it off before the first frost. This way the main outside is empty of water before the freezing temps start occuring. Also, do you recommend the controller on the outside or inside? What has been your experiences with were you put your controller?
Thanks,
Mark

Thanks for everyones help regarding my post. I hope others have learned something as well. I'm ready to start my project. I will start measuring this weekend and taking the appropriate pressure readings using a Toro pressure reader. I have also called the water company to get what they think the pressure is. I will obiviously compare the two. I will take before and after pictures of my yard and my project at each stage. When the project is complete I will post a link so everyone will be able to see the project and provide feedback. My yard looks aweful right now because Chicago had a bad drought this year and they restricted watering hopefully everyone will see the difference by late spring next year. Thanks again guys.
Mark