I am looking to install a copper shower pan and want to get a general understanding of the process. The pan will be 48" x 44" with an offset hole and it will have 6" high walls. The pan will sit on top of a 3/4" subfloor. Once the pan is installed, a mud base will be poured to allow for tile. Questions:
1. Is there any special underlayment that needs to go below the pan / above the subfloor?
2. Is there a specific drain that is required when using a copper pan?
3. When sealing the drain to the pan, any specific sealant that should be used? Or is it just a compression fit?
4. Is the pan free floating or should it be nailed to studs at upper ends of the pan walls?
5. I was going to cut the drain hole for the pan onsite. How much larger should the hole be compared to the drain pipe?

Any other advice on this is appreciated.
JT

Why not use a vinyl pan? Copper and mortar don't get along too well together.

when installing a copper pan you must adapt the trap riser pipe to copper tubing.
yes there is a special adjustable drain that solders directly to the copper riser and to the pan itself.
50/50 bar solder must be used.
the hole in the pan must fit tightly to the tubing sticking thru it.
do not use a plastic drain assembly meant for rubber or pvc pans...
when it is all soldered together, test with a couple of inches of water.

The subfloor under the pan needs to pitch towards the drain.

flat sheet of copper will not "pitch" to the drain very easily without "kinking".

i have installed dozens and dozens of copper pans and never sloped anything but the cement inside.
i have also removed a few that the pan laid flat and after many years of service they were as good as new.

Vinyl. That'll fix it.

As much as I can appreciate the craftsmanship that goes into a copper shower pan, and a mud set shower, I wouldn't bother with the quality tile-redi units that are now available.

Packy,
Great advice and thanks. So when you installed the copper pan, do you put an underlayment between the pan and subfloor? And is the pan just free floating or is it nailed up high? I figure I am going to run hardi-backer on the inside walls and that will sit just above the floor of the pan, so I know I need to avoid screwing into the pan!

And as far as the drain, can you suggest a model and manufacturer out there that I could search and see what they look like? I'm familiar with the PVC ones only.
Thanks,
JT

I would use something like a J R Smith floor drain with the copper caught in the clamping ring with a sealant.

go to...
[www.megawestern.com]
scroll down about 20 percent of the way.
see cast iron shower drains complete..
item number 67178 ABA6430
don't pay attention to the list price.
most plumbing supply houses carry this item
2 inch sweat drain with a 1 3/8 inch adjustable barrel.

you leave about 3/8 inch of 2 inch copper sticking up thru the pan , flux it, the pan and the bottom of the brass drain. using 50/50 stick solder, you gently heat everything and solder it all together.
the barrel will adjust enough to allow the cement to be sloped properly..

Why bother pitching a vinyl pan?

Codes don't support not pitching a lead or copper pan. Just because it's not as easy to pitch the copper, doesn't mean it shouldn't be done. I've had inspectors want to see all the flood test water drained, after they saw the water level, to make sure the pan is pitched and all the water drains out.
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From Michael Byrnes at a JLC.com thread -
Re: Shower pans

If your building inspectors are so particular, why do they ignore the IBC and ANSI A108 specs on shower pans.

All shower pans, whether they be made of copper, lead, PVC, CPE, or hot-mopped, must be fabricated to suit a subfloor that slopes 1/4-inch to the foot. Copper pans must be coated both sides with tar before installation, and should be secured to a brass clamping-ring drain housing to minimize electrolysis.

In my opinion, plumbers who continue to install copper pans without the correct detailing, and over flat subfloors, do so because copper does not get their hands dirty or require them to mix mortar or apply an adhesive--not because copper pans are superior, which they are not.

Who is responsible when the shower begins to leak or turn into a ceptic tank? Is it the plumber who installed the faulty pan, or is it the tile installer who applies his work over the plumber's? Generally, when a contractor installs tiles over another trade's work, the installer is saying "this substrate is OK and I can tile over it".

If you are stymied by the plumbing inspector, enlist the help of the manufacturer of the product you prefer to use, and have them make a pitch to the inspector or building department. I am very skeptical of inspectors who are locked into an inflexible position.

One way to bypass the building inspection department is to approach the health department, offer them a sample of wet mortar taken from a shower rip-out, have them test it for pathogens, coloform, and the like, and use the results to have the health dept trump the local code. It takes time, but it can be done. An article in your local paper about the **** the health department found in Mrs. Jones' shower floor because the plumber did not do a proper job can make a big impact.

Finally, who is writing your installation specification? Are they working with the mfg to affect a change? Perhaps you are constrained because you are a subcontractor. Many installers by-pass this by becoming general contractors.
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From John Bridge.com -

John Bridge 03-08-2009, 02:55 PM
Welcome aboard, Greg.

Copper pans seem to be a Northeastern thing, just like hot mopped pans seem to be a West Coast thing.

I have never heard of a copper pan having a pre-slope. I know that's a mistake, but that's how they do them. Better check with your building inspector before making any changes.
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"and should be secured to a brass clamping-ring drain housing to minimize electrolysis."..

this statemant makes me think this person knows very little about soldering.
i stand by my practice of installing a copper pan flat on the floor and soldering a good quality brass drain to a copper riser and to the pan itself.
how many of you have removed a terazzo shower base that was factory poured into a galvanized pan. have you ever seen it rot in the pan. only rot i have seen is up high.

quote; Who is responsible when the shower begins to leak or turn into a ceptic tank? Is it the plumber who installed the faulty pan,

That is WHY I do NOT install the shower pan. I let the tile person accept full responsibility for the entire shower stall.

quote; . have you ever seen it rot in the pan. only rot i have seen is up high.

Many, many times, including one at my former residence.

I know that grout is not water-proof. I know that mortar is not water-proof. To me, that means that the pan has to be an integral part of the drain, and allow for all the water to drain.If not, you will have a moldy mess in 6 months, or less. I could do it, but the thought of that amount of labor( by myself), makes me tired.I'm a perfectionist, and the pitching of dry-mix mortar, in itself, would be annoying.

I've lifted many a copper shower pan liner - some had given long service - but all came up looking like lace filigree. The cause, as mentioned already, was the aggressive cement in the bed mix.

Copper and cement, or sheet lead and cement, or 26 gauge sheet metal and cement dont mix.

As suggested, use the approved PVC or similar pan liners.

FWIW: its possible to manipulate sheet copper but first it must be annealed cherry red - too much work.

Schluter-Kerdi would be my choice, before copper and mud. They have a 48x48, or 72x72 pan, that can be cut to offset the drain. It's pre-sloped, and all you have to do is cover with the membrane, use their drain(designed for the system), and tile it. [search.yahoo.com] If you scroll down, you'll find videos showing how to offset a drain with their system.



Edited 2 times.

Just curious, I moved into a house with a bathroom roughed in with a 3 x 5 copper pan already in place soldered.
I noticed there is no rubber membrane beneath the pan. I plan to use hydro-ban after I get the copper mudded; however I am concerned there is no membrane under the pan on an old subfloor. Can I Hydro-ban or red guard the copper pan before the mud is put down? I was thinking it might add extra water proofing. Thoughts?