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.
