Lawn improvment

[Lerch]

My Zoshia grass lawn is thin and Bates recommended "top dressing" entire lawn with 1/4 " coarse builders sand ( turf is sand not dirt ) to thicken base. Has anyone ever heard of doing this? Anybody have any experience having this done? DIY-where get sand? Reputable contractor who has done it for you satisfactorly? Help!!!

Lawn Ranger