I saw my kitchen's ceiling was leaking today and traced it back to my shower. What type of drain is this and what's the best way to fix it? Do I have to cut my ceiling out in the kitchen? I suppose I should to prevent any mold, but I want to be sure of what I have to do before I make the first cut!

Thanks in advance!

If that black ring's a neoprene gasket then the drain's secured at the bottom with a large retaining nut and you will have to open up the ceiling to get at it.
I would open up the ceiling and loosen the nut and lift the drain enough to clean off the old seal and slip a small rope of plumbers putty under the drain lip and tighten the nut back up. If the shower base "gives" a bit when you step into it now's the time to puddle cement or mortar around the drain or any "weak" spots for support. If you don't you'll be doing this again in the future. Good luck, Tom

Thanks for your quick reply! I shouldn't have to worry about replacing the neoprene gasket then, right? Is a 12" to 18" square hole enough in the kitchen ceiling? Do I need a special wrench or something for the retaining nut?

Here's a pic of the drain from the kitchen. How the heck does that come off?

I have an idea that you can try if you would like to and if you have enough time.
First use a funnel or something that you can put water into the opening where the O-ring is, do not get any water on the outside of the flange on the shower base. Try to get a 1/2 inch or so but do not run it over. When you have some water in this area then watch it for a few minutes, if the water goes away that is a sure sign that the water is getting by the
O-ring and not between the shower base and the chrome flange.
If the water does seep out and the ceiling gets wet you will know it is a problem with the 0-ring and it need to be resealed. A trick to do this with out cutting out the ceiling is to use some things like a fish hook and slip between the PVC and the neoprene 0-ring, go under the ring and lift, move the hook around the circle lifting in different places until you get the ring to lift all the way out. You then have access to the pipe so that you can clean it, you can clean the ring, and then put some type of sealer in before you replace the 0-ring. I use DAP tub and tile caulk, speedball1 suggested using a ring of plumber's putty.
If this does not work you can then cut out the ceiling if you have to to re-tighten the brass ring on the bottom of the shower base.

Be sure and use a plyable sealer because you standing on the shower base and the movement might make a hard sealer break looose.

Actually, that's a Mustee drain, and it is caulked and pressed into the shower pan at the factory.

The only servicable part in this type of drain is the rubber 'donut' you see between the PVC pipe and the stainless steel drain 'shoe'.

Hopefully your leak is caused by the rubber 'donut' and not the drain shoe.

You should be able to pry the donut out as letmetellyu suggested and re-seal it with a good silicon caulk -- The silicone will act as a lubricant when re-installing the 'donut' and then as an additional seal when the caulk has cured.

Give the caulk a good 10 or 12 hours to cure before running any water down the drain.

Actually, that's a Mustee drain, and it is caulked and pressed into the shower pan at the factory.

The only servicable part in this type of drain is the rubber 'donut' you see between the PVC pipe and the stainless steel drain 'shoe'.

Hopefully your leak is caused by the rubber 'donut' and not the drain shoe.

You should be able to pry the donut out as letmetellyu suggested and re-seal it with a good silicon caulk -- The silicone will act as a lubricant when re-installing the 'donut' and then as an additional seal when the caulk has cured.

Give the caulk a good 10 or 12 hours to cure before running any water down the drain.

Thank you Growler,
nuklehed, be advised if you do need a new gasket,(see image) they are available. Regards, Tom

Thanks for all the feedback guys. It turns out the drain itself is not leaking. It looks like it's coming from the section of the pan where glass meets the fiberglass. It was freshly caulked a few months ago, and when done the canal under the door had its drain holes covered. My theory - since I see no visible gaps inside the shower - is that it was leaking through a screw hole under the glass. I cleared the holes and caulked the hell out of section I think it's leaking from. I'll test it with the morning shower and see how it goes. Thanks again!