Found this condition again in a three year old home. The drain pipe at the shower pan exteneded too far pass the drain collar. Directly below the shower drian I found a drywall blister with active moisture. Just wanted to share this with all…
Did you find the drywall blister or the pipe problem first?
I found the drywall blister first…
I think you may have to look further than the drain pipe being to high as being the cause of the leak below. As a plumber I’ve run across this many times without any problems. Ideally it is best to be flush or a hair below the gasket ring but will work if it is too high. The ring that holds the gasket would be difficult to tighten properly in this situation so the gasket may be improperly seated. If the shower drain is installed correctly with the gasket and retaining ring installed correctly it should not leak. I would look at the drain itself to see if it is loose. It could also be the trap under the drain. Also, it appears that the drain material is ABS. ABS is less stable on the hub portion of fittings than PVC and I have found many cracked hubs on all sizes of ABS. More so in the 3-4 inch ranges. Smaller diameter ABS also tends to warp.
In situations like this with wetness on the ceiling below a shower I have more often found it to be a loose drain which would need replaced. FYI- it is possible to replace it from the top with a special shower drain made for this purpose (Plumb-rites Wingtite Shower Drain ). This drain has saved me many scrapped knuckles not to mention time and mess.
Thanks for the reply… And well noted on my behalf.