# Shower pan



## ICE (Mar 26, 2015)

Does the shower pan have to slope towards the drain or can it be flat and only the finished shower floor is required to slope towards the drain?

The code is the CPC. Not the IRC.  411 talks about a shower receptor that requires a slope. If that receptor is the stall itself and the finish floor is all that's required to slope towards the drain, the pan could then be anything including sloped away from the drain.  There would be no rule regarding the pan.

I have been told that the pan isn't required to slope.  Seems wrong to me but this came from one of our engineers.


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## mark handler (Mar 26, 2015)

See 2013 CPC 408.5

http://www.iapmo.org/2013%20California%20Plumbing%20Code/Chapter%2004.pdf

 FINISH floor .... shall be sloped not less than 2 percent toward drains.


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## ICE (Mar 26, 2015)

.....shall be lined with sheet plastic, copper ....built up

Lining materials shall be pitched......


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## conarb (Mar 26, 2015)

Tiger, Mark has linked you to the 2010 CPC, we are now on the 2013 CPC, you are right, your engineer is wrong, a preslope is required:



			
				\ said:
			
		

> *408.7 Lining for Showers and Receptors.*Lining materials shall be pitched 1/4 inch per foot (20.8
> 
> 111/m) to weep holes in the subdrain of a smooth and solidly
> 
> ...


BTW, I hear that the 2016 code is going to do away with dams and water testing altogether, every shower I've built in the last several years has been curbless with linear drains, linear drains look better, eliminate a trip hazard, and they are looking forward to the day when accessibility requirements are going to be applicable to all occupancies.

EDIT:  I see he's caught his mistake and edited his post to reflect the 2013 code.


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## ICE (Mar 27, 2015)

This question came up with an upset contractor.  I posted some pictures about this in another thread.  The contractor had me replaced because I am insisting on a slope and that the drain be installed.  The inspector that replaced me told me that I am wrong and the rubber pan need not be sloped.  We have a Mechanical/Plumbing dept. so I asked them.  I was told that I am wrong and no slope is required.

If I have been wrong for a long time I have made countless installers do it over needlessly.  I have found many internet videos on shower pans and they all have a slope.

I think I will continue to get it wrong.  Hopefully, the engineer, inspector and contractor will allow me to agree to disagree.


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## mark handler (Mar 27, 2015)

Refer them to the code

2013 CPC section 408.5


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## conarb (Mar 27, 2015)

ICE said:
			
		

> This question came up with an upset contractor.  I posted some pictures about this in another thread.  The contractor had me replaced because I am insisting on a slope and that the drain be installed.  The inspector that replaced me told me that I am wrong and the rubber pan need not be sloped.  We have a Mechanical/Plumbing dept. so I asked them.  I was told that I am wrong and no slope is required.If I have been wrong for a long time I have made countless installers do it over needlessly.  I have found many internet videos on shower pans and they all have a slope.
> 
> I think I will continue to get it wrong.  Hopefully, the engineer, inspector and contractor will allow me to agree to disagree.


Tiger:

This is going to be a big issue with curbless showers, I screwed up recently and it has cost me over $20,000.  I built a home with 4 curbless showers, with a curbless shower the entire room becomes a shower plan, what I was really concerned about was the master bath contained a  *Japanese Ofuro Port Orford Cedar tub*, Ofuro tubs do not connect to drains but you fill them to over flowing and as people get into them water splashes out all over the floor, then when you pull the drain 550 gallons of water dumps onto the floor.  I decided of course to make the entire rooms shower pans and had my roofer figure installing preslope on the entire floors, the owner tended to be picky on some things, I noticed him measuring the heights of all cabinets after they were installed so I got thinking that people would be standing out of plumb in front of the mirrors, the heights of the vanities would be different from one end to the other, and I didn't really need to run the preslope the 15' depths of the rooms, so when the roofer showed up to hot mop the pans I told him to run the preslope material level until he reached the ends of the vanities, that would still give me over 4' of preslope outside of the linear shower drains.  I also, for added protection, put Schluter's Troba drainage mat on top of the pan to facilitate the quick dispersal of water under the mortar bed, at shower pan inspection (this area also has a shower lathe inspection at the same time) I left the pan material turned up 4" at the doors to flood the pans, after inspection I used a knife to cut the turned up pan material where it intersected the rift grain walnut flooring of the other rooms.

After the people moved into the home and had been in there about 3 months one pan started leaking at the doorway, I first removed the limestone around the outlets under the linear drains hoping that they had been clogged up by the mason when laying the stone, that didn't work so I tore the stone up at the doorways and had the roofer create a dam so the water couldn't reach the doorways, but that bothered me because water would always be laying in the drainage mat destroying the pan.  Eventually I tore up the entire center of the floor and added a floor drain to take the water out through it's weep holes and that has worked.  This only happened in one bath and not the bath with the Ofuro tub, the reason was that level isn't necessarily level, I checked the joists and the joists sloped about ¼" under that bath over the 15' towards the doorways.  I was there this week to check it, taking moisture readings in the adjacent walnut and looking at the condition of the limestone, I am going to start restoring and sealing the limestone shortly, but told the owner that do to moisture readings I am going to wait another year before resanding and refinishing the walnut floors.

So tell your contractors who don't want to install preslope the experience of an old contractor and the money it cost him, I learned how to do curbless showers doing ADA work, of course the guys you are dealing with may be the cheap contractors without bonds and insurance that our ADA guys here want to do ADA work, they aren't going to come back anyway.


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## ICE (Mar 27, 2015)

conarb said:
			
		

> the guys you are dealing with may be the cheap contractors without bonds and insurance


Oh it's much worse than that.


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## jdfruit (Mar 30, 2015)

It's also much worse than that when you work with ignorant supervision that won't research for accuracy before answering.


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## mtlogcabin (Mar 30, 2015)

Ice

I asked the IAPMO instructor today and he agreed with you. the code requires the pan to provide the proper slope


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