Relocation shower drain problem

[Johndel]

Hello,

I am in the process of replacing my shower after the tiles mounted to drywall finally gave way after 24 yrs.

Bit o' background/status:

So far, took down to studs, straightened reinforced walls, replaced rough-in with pres. balanced. Plan to cement backer board, with Schluter/Kerdi over, then tile everything.

My problem.

Now I need to move the drain about 6 inches in order to have it centered and to have it ready to receive Schluter system drain. Existing drain is not compatible.

Problem is the drain is tightly connected to the 4 inch toilet drain leaving only a 1/2 inch "exposed" 2 inch section to cut into. Since that is not enough to glue a fitting to that means going into the 4 inch section. I would replace the Y in the 4 inch. Question: How do I get the coupling and new Y into place if I can't move the 4 inch?

Some type of union would work but would prefer not to put in a rubber coupler in this area (not sure that is even code), since the area is hidden once I replace the substrate and put in the shower floor.

No picture yet due to most of floor remaining in place. Want to have a plan before arming up with the sawzall.

John

[jadnashua]

They make a special drill bit designed to bore out the old pipe from the fitting and leaves a nice clean hole to glue in new...I think it's called a rambit, but one of the pros would know for sure. No idea if you can rent one, or if you have to buy, how much they cost. If expensive, and you can't rent, it might be cheaper to get a pro to do it.

Unless this is a steam shower, you really don't need the cbu...drywall is plenty good enough when using Kerdi (and is the recommendation with that waterproofing membrane). If you haven't been to www.johnbridge.com for tiling, suggest you do.

[Johndel]

Jim,

Thanks, I will get one of those tools, price varies btwn about 20 to 50+ depending on the brand/quality. Good thing to have anyway, have thrown away pipe assemblies before.

Thank-you also for the John Bridge site. I have done some looking there and have wrestled with the Hardie/CBU vs. Drywall.

Drywall Pros:
Ease of working
Cost
More Kerdi compatible (though with CBU as long as sprayed w/ H2O prior to thinset seems not too much issue).


Drywall cons:
Moisture resistance (one wall is outside and that was where my problem was before).
Some reduction in structural strength (realize this is not much) with sturdy framing.

Realizing that with Kerdi, no moisture will get to drywall from shower. Concern is over time (years) the warm shower will cause condensation to form on the drywall. CBU would not be affected by this but drywall would.

I thought is some fairly cheap insurance, at least on the outside wall.

Thoughts?

Again thanks for the help. I willl be buying one of those tools, the value of forums help me again!

John

[jadnashua]

It can only condense if there is moisture there - Kerdi prevents that. Also, since it is on the (hopefully) warm side during the heating season, again, if there were condensation in the wall, it wouldn't be on the drywall, it would be towards the outside wall.

BTW, the paper on the drywall has a grain, and it is stronger along the long side, so for maximum strength between studs, place it horizontal. Same idea as with plywood. Drywall with kerdi and a couple of layers of thinset along with the tile, and it will be plenty stiff enough. If you can accommodate it, for a little extra insurance, you could always go with 5/8" drywall, too. Depends on what's going on the outer edge transition whether that would be easy or a pain. Save yourself some money and aggravation, drywall is fine except if it is a true steam shower, then they want CBU instead (it would only likely be a factor in a commercial steam shower, but they carried it over to the residential ones as well).

[Redwood]

The tool to drill out the fitting would be a Rambit as jadnashua stated.

[hj]

I cannot imagine how a shower drain would only have a single short section of pipe to make the connection. You may be making a minor job into a major remodel.