Drum heads need monitored and replaced regularly. If you can see through the coating, or notice any dents, it’s time to replace them. I would expect to replace the snare batter head every 3-4 weeks and the tom batter heads every 4-6 weeks. The resonant (bottom) heads and the kick batter head only need replaced once a year or so. The Kick resonant (front) head rarely needs replacement. You should always have extra drum heads on hand at your campus, in case of emergency, especially snare tops and bottoms.

Traders Point Drum Head Type