You deserve a good job, regardless of who installed your sprinkler system.  There is more to a good job than the number of heads and zones.  A sprinkler system can include the best components, but if good design and installation techniques are not applied, the results can be years of costly repairs and alterations.  Before you give the job to a contractor, be sure they are fully insured (Liability and Workman's Comp) I cant tell you how important this is.  Here are just a few things that you can check for at the time of the installation that can help prevent unnecessary future expenses.

___A 1" all copper plumbing tap installed. (should include 1’’ full-flow ball valve and drain)

___A 1" Pressure type vacuum breaker is installed. (with copper all the way into the ground)

___Copper exit hole is caulked. (to keep out insects)

___Controller is installed in a convenient location. (Mounted securely and at eye level)

___ Solenoid valves are installed on a P.V.C. manifold. (A stronger more durable plastic)

___All Solenoid valves are enclosed in a heavy duty valve box. (Not wood or metal)

___Exposed control wire is enclosed in a conduit. (to prevent damage by weed whacker)

___Control wire exit hole caulked. (to keep out insects)

___Underground control wire is heavy duty, black in color, and is labeled as direct burial)

___All outdoor wire splices are water tight. (will prevent corrosion and possible valve failure)

___All outdoor wire splices are enclosed in a heavy duty valve box.

___All Sprinkler heads are installed plumb & level.

___Sprinklers adjacent to concrete allow room for lawn edger or snow shovel.