I recently installed a new acrylic shower pan and I used Oatey "no-caulk" drain (metal). I did a water leak test for 3 days and I saw a small amount of moisture at the bottom. On inspecting I found the water is probably dripping in a small quantity from the gasket itself becasue the silicon seal is perfect and the paper washer is completely dry. Apparently the pvc pipe thats coming from the ground is not cut properly from the top and its sticking out a little bit as shown in the picture. That allows the water to sit in the gap and eventually it start leaking through the gasket. I was wondering if its ok if I fill the gap between flange and the pipe with silicon so it level with the pvc pipe and instead of water sitting in the gap it just goes right to the drain. Please advise.
Note: The shower is installed at the basement of the house so there is no access unless I take the whole pan out.
Silicone is a great product and should work for this purpose. Just be aware that it may be a temporary fix. I would suggest going to a local plumbing supply store and ask their opinion. They have seen many odd situations and just may have the answer that you are looking for.