Originally Posted by
Mitchell Toelle
Any pan leak test requires that the drain line be blocked below the weep holes in the drain flange, not just capped or covered at the surface. You should get one of those inflatable drain blocks that plumbers use, remove the drain grill, insert the inflatable block and inflate it. If you just cap the drain, water permiates through the tile and mortarbed and weeps through the weep holes, thus allowing the water level to drop and gives a false test.
IMO, a test needs to be for 24 hours or it's not a real test. I understand that your requirements are for less time, but that 15 min. test is really of very little use and can subject you to greater liability. I have called for long pan tests on many showers, where the Pest/ Termite Inspector already did their short test and found nothing, only to find that the pan did, indeed, leak.
I will do them for my Client for an extra fee, but I usually just recommend that a licensed Plumber be used. All of the pans I have referred have shown other indications of past leaking (some very minor looking) which raised my suspicions in the first place.