View Full Version : Installing a new shower in a concrete floor, high-rise

12-08-2009, 11:36 AM
I just purchased a condo in a high-rise and am hoping to make some master bathroom/closet renovations. The condo layout is such that there is one large bathroom with a full shower/sink/toilet directly parallel to the master bedroom walk in closet which only has a small bathroom with a sink and toilet. My question is... Is it necessary to drill new drain holes in order to put in a second shower in the master closet or can I plum the drain to link to the next door shower drain? This would make things much much easier... If not, generally home much does installing a new drain in a high-rise condo with concrete floors generally run... ballpark? Thanks

12-08-2009, 11:43 AM
You will need to provide the shower it's own trap which means going through the floor (and in youir downstairs neighbor's ceiling). Code requires each plumbing fixture to have it's own trap (with a few minor exceptions).

I don't think anyone here can give you a quote as cost can vary widely from area to area.

12-08-2009, 01:04 PM
If you are coring a prestressed concrete floor, you will need to x-ray the floor first.

It's going to be a bunch.

12-08-2009, 03:34 PM
Depending on where you live, state and local laws, and the condo by-laws, any changes like this may need the association's approval. You may not get it. Local laws usually require this to be done only by a licensed plumber with permits. Depending on how the ceiling is done, and how friendly your downstairs neighbor is, you may not get permission to enter their unit unless it is something like to fix a leak. Tearing out the ceiling and restoring it could get ugly. Now, if it is a dropped ceiling, it may not be a big deal. You may need to not only move a drain, but install a new vent as well, so it is likely at least a couple of holes through the floor.

12-09-2009, 07:57 AM
As stated, there is NO WAY to tell what is involved until someone checks your existing piping to see what would have to be modified. BUT, all homeowner associations require that alterations be performed by licensed contractors, if for no other reason than liability and insurance coverage. For those reasons, you need a local plumber to check as much as he can, without disturbing your downstairs neighbor, until work starts. At that point, you would have to get permission from the downstairs person so you could access the pipes in his ceiling. Not always easy, or possible, with some people.

12-09-2009, 12:36 PM
Check out www.saniflo.com


Sanishower is a small gray water pump that may be used to pump waste water away from a shower, sink, bar sink, or other fixture. The Sanishower is small enough to fit inside a wet bar cabinet, or even beside or underneath a raised shower base. It also can be used in a variety of small gray water pumping jobs, such as a condensate pump. The Sanishower will pump up to 12 feet in height.

12-09-2009, 02:00 PM
The guy is living in probably a million dollar condo, and you want to give him a Saniflow toiler???

12-09-2009, 04:51 PM
The guy is living in probably a million dollar condo, and you want to give him a Saniflow toiler???

Sure why not . I'm just giving the guy another option .

12-10-2009, 07:45 AM
figure out where the drains are, in your dropped ceiling above you, and you will have replicated the "floor plan" of your own drains in your downstairs neighbor's ceiling. One good reason to do this is to know where the hole perforations are already in the slab. If you are lucky, you will find your concrete building has large holes for small pipes, so new holes don't have to be cut. But even cutting a hole might be no big deal.

Then, you can also ask here how you can add a shower. It will depend on your existing drain pipes.

12-10-2009, 08:02 AM
figure out where the drains are, in your dropped ceiling above you, and you will have replicated the "floor plan" of your own drains in your downstairs neighbor's ceiling.

There may be differences depending on a lot of factors. This may correct or may be incorrect. This would depend on the location within the building and whether or not there are different floor plans above and below as well as to the sides....

09-15-2012, 11:02 AM
I have a similar question (and hope it's appropriate to add to this thread rather than start my own).

I bought a condo in a mid-sixties building. The existing bathroom layouts are crowded and I would like to shift the toilet by no more than a couple of feet to allow me to replace the tub with spacious shower. In the other bathroom I would like to move the tub/shower drain by a couple of feet.

I have had the ceiling in my bathroom taken down so I can see the structures above. There are concrete joists centered at about two feet and a concrete floor (my ceiling) in between. I can see from holes that have been cut in my ceiling that the floor is something like four inches thick and is reinforced with rebar. The toilet drain pipe is cast iron. I assume the same thing is true for my unit. I would like to shift the toilet laterally within the space between the joists (without crossing one). It is ok with the building management for me to do this -- but I am not sure about the practicality or how it can be done to code.

One contractor advised me that if the neighbors downstairs will let me open up their bathroom ceiling it will not be difficult to cut a hole in the concrete floor for the new toilet drain and reconnect it to the soil stack. (The folks downstairs are doing their own renovations so they might be amenable to this. Subsidiary question, though, is how to coordinate the building dept inspection so that their bathroom ceiling is not open for too long.)

A second contractor told me to forget about it, that if the new hole cut into any rebar the building department would never allow it.

A third contractor told me that even if the folks downstairs will not give me access, he could cut a rectangle out of my floor from above, on 45 degree angles, lift out the rectangle, shift the plumbing, and then set the beveled rectangle of concrete floor back in place. He showed me examples of having done this in other places. It looks ingenious but I have no idea whether it would meet code or be safe.

I would appreciate the insights of people on this forum! Thanks very much.

09-16-2012, 03:36 PM
Moving drain lines in a condo is a very tricky thing to do. Getting permission to work from below and paying for all the changes and repairs can be costly. On one project my client offered up new painting to the entire bathroom after we dropped their ceiling. This is the only time I have been given permission to do so.

Moving showers is easier since you can leave the drain location and just make the shower where you want it. Quick Drain USA makes a side outlet linear drain that is fully cUPC approved for use in residential and commercial renovations. The drain sits about 2 1/8" off of grade and outlets out the back. Using a drain like this you can position the drain in a new location or even the next room if venting and drain lines allow for this.

Using a wall hung toilet can help you achieve new locations for toilets and if planned right the exposed plumbing can be a seat in the next room or in the bottom of a dresser.

Trying to move the pipe is a real challenge. It never hurts to ask but planning the space with the existing drain lines is always a safer bet.

Good luck.


09-16-2012, 03:45 PM
Thanks, JW. I will look into the Quick Drain USA device.

If the neighbors downstairs were not also doing renovations (that they are going to move out for a while to get done), I probably wouldn't even ask them.

Thanks again.

09-17-2012, 07:12 AM
Thanks, JW. I will look into the Quick Drain USA device.

If the neighbors downstairs were not also doing renovations (that they are going to move out for a while to get done), I probably wouldn't even ask them.

Thanks again.


Here you can see the drain going in. We had never done one before this so we left all the plumbing exposed for inspection and flood testing. After we had approval we filled over the drain pipe and prepped the tub deck for tile.

If your neighbor is moving out and they have dropped ceilings in the area where you are moving pipes then it might be worth asking. They are doing you a favour by letting you do this. Maybe offer up a round of golf or spa day.

They might surprise you and say no problem - go for it.

You might also tell them you will use a premium sound proofing material. If you use Noble Company's Sound Reducing membrane under your tile they won't hear you upstairs.

Anytime you drop a stack you run the risk of falling debris clogging the line. Make sure your plumber plugs the drain line with something before he snap cuts the pipe.


Remember that you need to slip on a no-hub fitting so you will need t o factor that in to the shower floors calculations...

The drain only come in one size. I was able to make this shower larger by customizing the shower pan.


I installed the drain and ordered a larger strainer (tile insert) and used some custom 316 Stainless and Mapei's 315 to fill the open exposed membrane after the marble was installed.

You can see a finished picture of the steam shower here;




I used bags of setting materials to hold back the water. I later sett this flap done over the tub deck.

09-17-2012, 07:34 AM
Make sure any work you do in the high rise meets building codes. In Florida you are required to flood test the new shower for a minimum of 15 minutes but 24-72 hours is much better.

This shower we flood tested for I think three days.

The process is easy with an inflatable test plug and extension hose for the plug.


A 2" inflatable test plug works best.


This needs to slide in to test the connection of the drain to the plumbing line.


Fill with water and mark. Call for inspection. I printed of the IAPMO reports for the drain, the Noble Seal TS and the Aqua Defence used in this build.

Inspector left this for me....


09-17-2012, 07:50 PM
JW, thanks for the additional information and photographs.

I am excited about the other suggestion of the wall-mounted toilet. I found the Geberit installation video online and I think that very well may be the solution for me. It even turns out that a colleague at work just had one installed in his house so his plumber is very familiar with this.

Thanks again!!