I am remodeling a basement bathroom. I demo'd the shower and its tile to reveal rotted framing. I believe this is due to an improper or (more likely) not existent shower pan -- there was no water proof membrane between the tile/thinset and the framing.

Can I build a proper shower pan utilizing the existing functional shower drain? The drain is at the correct location but the drain's grate sits at the level of the conrete. The concrete floor slopes downward toward the drain. The slope is perhaps not quite enough, but I was thinking I could address this with a Pro-Slope system or pre-slope mortar.

How would I attach the shower pan membrane near the drain to allow water that gets through my tile/mortar layer to run into the drain? Can I shape the mortar bed beneath the eventual tile to allow for fitting a shower drain at the tile level above the existing drain?

Do I need to bust concrete, remove the existing drain and install a clamping ring model to make a proper shower pan happen?

Er.. I meant 'grate' rather than drain -- bolded below.

Quote:

---

Originally Posted by zozozo

I am remodeling a basement bathroom. I demo'd the shower and its tile to reveal rotted framing. I believe this is due to an improper or (more likely) non existant shower pan -- there was no water proof membrane between the tile/thinset and the the framing.

Can I build a proper shower pan utilizing the existing functional shower drain? The drain is at the correct location but the drain's grate sits at the level of the conrete. The concrete floor slopes downward toward the drain. The slope is perhaps not quite enough, but I was thinking I could address this with a Pro-Slope system or pre-slope mortar.

How would I attach the shower pan membrane near the drain to allow water that gets through my tile/mortar layer to run into the drain? Can I shape the mortar bed beneath the eventual tile to allow for fitting a shower grateat the tile level above the existing drain?

Do I need to bust concrete, remove the existing drain and install a clamping ring model to make a proper shower pan happen?

---

You could try using the Ditra schulter system rather than a complete mud build up. You can tile right on the Ditra. YouTube - Ceramic Tile Installation with Schluter Ditra If you jmust build a mud plan from scratch good luck to you, I won't even do them any more but here are the steps. How to Build a Shower Pan last but not least you could slip in a Swanstone acrylic pan, they run about $350 for a 32x60

If you have cast iron pipe then you will either have to use an older method of installing the pan or you will need to transition over to PVC (or ABS plastic) pipe and the proper membrane strainer assembly.

Here, if a cast iron pipe you will need to dig down far enough on the old pipe that you can cut the pipe using an angle grinder or reciprocating saw with bimetal blade and then install a SHIELDED CLAMP (see picture) and new PVC membrane type shower strainer (see picture)... all sold at home depot (including the membrane and membrane cement).

If PVC or ABS plastic pipes then you should just need to dig down far enough to cut the pipe and attach the right strainer.

Check out Ballenger's link on building a custom shower... presloping the pan is critical... and then pop back if you have more questions.



MARK

Mark gave you excellent advice. In addition: half of the time you can reuse Cast Iron shower drain. If it is plastic, than chances are you will have to replace it. It is not a bid deal at all to do.

Thanks for the quick responses.

Mark, If I stick with the existing cast iron drain, what is an 'older method of installing the pan'?

If I choose to cut out the old drain, what should happen to the trap bypass line that currently is plugged in the bowl of the cast iron drain?

Milo, How do I know if I can reuse the cast iron drain? How do I build a shower pan reusing the drain? The articles I've read all show the use of drain with a clamping ring like the picture Mark posted.

If the drain was not damaged during demo, you can reuse it. Unscrew 3 ss screws, lift upper portion of the drain, take wood chisel and thoroughly remove all old asphalt. Now you can proceed with hot mop.

You don't really do anything else with the drain. Just make sure you don't spill demo debris into the drain. If positive, than take shop-vac and vacuum it all out.

Hot mop is usually done by licensed hot mop contractor. It has been explained here many times including videos. Go to Search and look for Custom Shower Pan Installation.