Re: Help! Leak in shower drain trap
From the way it looks in the picture, you have ABS connected to PVC connected to the shower drain. It appears that you have had some leakage at the shower drain also with the deposit build up on the PVC. I would say it is going to have to be redone from the drain to the ABS drain and some rerouting is called for. If this is a little out of your league as you stated, I would go with calling a plumber as i.m.plummin suggests. You don't want to have to tear down a ceiling again.
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