Pre-Slope, Shower Pan, Curb and CBU - quick help needed [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile

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JeanJet
02-28-2008, 05:12 PM
Hi - I have some questions about shower pan construction and pre-slopes. I have spent hours reviewing the library materials/tile forum posts and have a good understanding of the do's and dont's of shower-pan, curb and shower wall installation. However, my GC disagrees with several of the points most emphasized on by the pros on this site and I don't feel able to adequately respond. The GC is someone we really like and who has proven to be very thorough, honest and reliable. On an extensive renovation, this is the only issue about which we have disagreed. I really don't want to be unreasonable but do want to make sure not to end up with a pretty shower that leaks. I'd like to ask some questions in hopes of becoming better able to discuss the issues with him tomorrow. Here goes:

1. As I understand it, installing a pre-slope under the liner is critical to the overall water management system of a shower. According to the GC, this method is not used in the Atlanta area and the slope is added by the tile installer after the liner and drain are installed by a plumber. Is this a sound method? If not, why? Also, who usually installs the shower pan, plumbers or tile installers?

2. My shower so far consists of: a plywood floor directly over which pvc has been laid (no water barrier, no lath, no mud). I have been told that the pan/curb installation methods outlined in the Library are not current methods and that the bid did not include such work. Can a shower without these things be reasonably considered to be a professional installation? Is the water barrier, lath, mud preslope, unpenetrated liner currently still the correct method for building a non-leaking shower pan or has this method been replaced by another?

3. Is notching the studs (or adding furring strips of lath) to accommodate the folded liner (so the cbu doesn't flare out and crack the grout) too difficult to expect in a renovation (as opposed to new construction)?

4. The liner only covers the top of the curb (does not extend over the curb) and is nailed into that top surface. I am trying to have the pan re-done but have been told that no one does this (the mud-man way) anymore and that the bid for installing a shower did not anticipate this work. Is expecting the liner to be installed at a minimum of 3" over the finished curb height, totally covering the curb and attached only at the top edge and outside of curb over and above what someone should expect of a professional installation or are these well-settled industry standards?

5. Does anyone have a referral for a plumber/tile installer in Atlanta who installs mortar shower pans in the manner recommended by John Bridge in the Library reference materials?

Any info you can provide would be so appreciated. Thank you very much!

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jim mclaughlin
02-28-2008, 05:31 PM
Jeannie

1) Tile council of America requires pre slope, Atlanta is in America. Next ?
( I install my liners)
2) It is current
3) Only too difficult if you a) do not know any better
b) trying to cut corners
4) If I understand your description correctly this will surely leak. Can you take a
picture?
5) I am sure you will get some responses shortly

jadnashua
02-28-2008, 05:39 PM
I don't have my copy to quote, but this is close: "The liner shall be installed on a sloped bed...".

What's common practice does not mean that it meets the industry standards. For example, some people in MA insist a copper pan flat on the floor is absolutely the best possible thing. Well, it shouldn't leak for a long time, but as you've discovered, it can lead to damp tile, and mildew, along with that lovely swamp smell.

I don't know if you can access the TCNA specs on-line, but that is what the industry standards come from along with ANSI.

Some local inspectors don't seem to care about a sloped liner, and only care about not leaking prior to giving approval. Those guys should be taken to task...

MudGuy
02-28-2008, 05:40 PM
Hi Jeannie -

Quick answer.

Congrats - You know more about preparing a shower for tile than your General!!

I would never install a shower that, I, personally didn't prepare for tile.

You need a competent tile installer period.

You must install a pre-slope drypack prior to installing your pan liner.

Pan liner should wrap the curb and down to the floor with outside corners fashioned and glued where the curb meets the side walls.

Pan liner should be at least 3" above finished curb - I take mine higher.

No nails in the curb. No nails in the curb. No nails in the curb.

Good on ya'!!

:D

Hamilton
02-28-2008, 06:14 PM
Hi Jeannie

John Bridge wrote some great tutorials on shower construction in
our world famous "Liberry" :) Take a look at his handy work with pics
included Shower construction (http://johnbridge.com/vbulletin/showthread.php?t=5434)

JeanJet
02-28-2008, 07:31 PM
Hi - thanks for all of your quick replies.

After finding the nails through the liner on top of the curb, I put together a summary of how to build a shower pan and curb from h info taken from JB's "How to Build a Shower Pan" and "How to Build a Mortar Curb" tutorials in the Liberry. I gave my GC that summary yesterday, together with copies of the shower pan and curb tutorials. The questions in my original post were based on his response today to the summary and tutorials I gave him yesterday.

From what I understand, the City of Atlanta requires the shower liner to be installed with water in it before they will sign off on the plumbing inspection. Question: Since the pan is something the tile installer should do and knows how to do, how do you suggest I work around this kindof backwards city plumbing inspection requirement?

Question for MudGuy: Can you give me more info about how to fashion the outside corners of the liner and glue where the curb meets the side walls? I didn't see that mentioned in the tutorials and am not sure I understand. Is this the same as "dam corners?" I saw those mentioned a couple of times but not in the tutorials and never with a description of when and why to use them (or how to fashion them/where to buy them)

Third (very important) question: About how much should I expect to pay to have a correctly installed shower pan (roughly 3'X5") and mortar curb (roughly 5" long)? I'm just looking for ballpark figures, an estimate would really help to put things in perspective.

Can't say thanks enough.

Scooter
02-28-2008, 07:47 PM
Question 1: The drain is mounted with the top half of the 2 part drain placed in a safe place, a preslope is floated, and the shower membrane applied to the floor and up the walls. Then the area is flooded with water and the inspector makes sure the shower does not leak. Thats how its done.

Question 2: I don't run the membrane to the outside walls. Just inside walls, the three sides of the curb and the verticle jamb. No water should get to the outside walls.

Question 3: Materials will run about $250-350 for the membrane and mortar. I'd charge you double that to install the same and it would take me about a day.

JeanJet
02-28-2008, 08:40 PM
Hi - Thanks for the additional info and, sorry for being thick, but I've got a couple more questions.

1. the liner filled with water is required in Atlanta to pass the plumbing inspection. Since plumbers are not likely to be in touch with TCNA specs, should I have a tiler do the shower pan, pause for plumbing inspection, and then have the tiler come back again to install the tile?

2. additional price estimates would be helpful:)

Thanks again for the help!

MudGuy
02-28-2008, 08:49 PM
From what I understand, the City of Atlanta requires the shower liner to be installed with water in it before they will sign off on the plumbing inspection. Question: Since the pan is something the tile installer should do and knows how to do, how do you suggest I work around this kindof backwards city plumbing inspection requirement?

Nothing to work around here Jeannie. A competent tile installer in your area will already know the rules. It's common place for the tile installer to build the pan and have a city inspector sign off on it. It's actually the plumbers "pan inspection" but the plumber, builder or tile guy can call it in. In New Mexico, they only inspect for slope (pre-slope), no water test.


Can you give me more info about how to fashion the outside corners of the liner and glue where the curb meets the side walls? I didn't see that mentioned in the tutorials and am not sure I understand. Is this the same as "dam corners?" I saw those mentioned a couple of times but not in the tutorials and never with a description of when and why to use them (or how to fashion them/where to buy them)

Excellent visual of folded inside corners and glued "outside" corners here in the Liberry. View through all the pics. :)

http://johnbridge.com/mortar_bed_shower_floor.htm


About how much should I expect to pay to have a correctly installed shower pan (roughly 3'X5") and mortar curb (roughly 5" long)? I'm just looking for ballpark figures, an estimate would really help to put things in perspective.

I wouldn't even be concerned with this. The estimate you need should include the pan, walls, tile installation etc. from a "real" tile installer, doing the complete shower installation.

:)

JeanJet
02-28-2008, 09:15 PM
Thanks, Mudguy. The info you and everyone else has generously provided has been a huge help, this forum rocks.

The reason I'm interested in getting a feel for range of prices to expect for correct pan installation (sans tile installation) is this: My GC has said that installation of a shower pan, curb and enclosure per the JB and TCNA specs weren't factored into his bid to build and tile the shower. So...I'm trying to get an idea of how much $$ I should should reasonably agree to add to what we're already paying so that we can get the pan and curb built correctly before the tile is installed.

Estimates anyone??!

MudGuy
02-28-2008, 09:42 PM
My GC has said that installation of a shower pan, curb and enclosure per the JB and TCNA specs weren't factored into his bid to build and tile the shower.

Ughh.....who's specs was he planning on using?? :uhh:

These methods have been adopted by all competent tile setters across the country!!??

JeanJet
02-28-2008, 10:57 PM
Hi - point made. Sorry to beat a dead horse :deadhorse but it'd still be really helpful to have an idea of how much it will cost to have the pan/curb installed correctly. Scooter gave me an estimate but, on the chance that prices might vary between southern Cali where he is and Georgia where I live, I thought it would be good to see a range of estimates if possible.

Please, estimates anyone??

Thanks!

MudGuy
02-28-2008, 11:07 PM
Ok, I'll bite....sheesh. :D

Do you have a shower bench?

Edit - That was a serious question, BTW.

JeanJet
02-29-2008, 07:37 AM
Hiya, Mudguy - nope, no bench. Just a 3x5 space (took out a tub and replacing with a big shower unit).

Big thanks.

MudGuy
02-29-2008, 08:39 AM
Jeannie -

In a bid, your pan area and curb would amount to about $650.00. It's not itemized, just factored in to the overall project cost. However, if someone were to call me to strictly put in a shower pan, I wouldn't do it unless I was providing the entire installation. And if I did agree to do it, I'd add another few hundred. There's just too much work involved in just setting up shop to install a pan without getting the whole package deal.

After completing the pre-slope and pan liner, someone has to install the walls (usually me). After the walls are installed, the pan can be finished (drypack slope on top of pan membrane). It takes an extra trip. If the pan is damaged during wall install and I don't catch it and/or no one says anything about it, who's at fault when the pan ultimately fails and you have water damage? The pan could be damaged after I've done my job, too, but who's to prove how or when it happened?

As already said, find a guy who knows what he's doing who will do all your turnkey tile installs. If you were to find someone who agreed to do a pan install, yet, your GC has some other hack to do the tile work, you're ultimately not going to be very happy in the long run.

cx
02-29-2008, 09:14 AM
Jeannie, the pre-slope for the shower pan is actually a requirement of the plumbing code. The TCNA Handbook indicates such a slope in their method drawings, but it's considered part of the plumbing as far as building code is concerned.

That's why the pan liner is required to be installed by the plumber. Unfortunately, most plumbers don't have a clue about the required pre-slope and some won't do one even if they do know it's required. That's why you'll find so many competent tile installers tearing out the plumber-installed shower pan and doing their own.

Even more unfortunately, many inspectors either don't know or don't care and approve many shower pans without such pre-slope.

But it's still a code requirement and you can still require that it be done correctly.

How does your GC wanna do the curb if he doesn't approve of the "outdated" lath and mud method?

My opinion; worth price charged.

Hamilton
02-29-2008, 09:27 AM
Hi Jeannie

Hope things are going ok. I dont want to confuse you, but here in cali
we have another kind of pan called a hotmop. I doubt they are doing
these in atlanta. A hotmopper charges about $350-$400, and because
of this my price would be in the same ballpark for a pan liner like the
one you are installing . Just to give you another
number, but please keep in mind that all areas of the country price labor
and materials differently reflecting the economy etc. Hope everything
works out for the best and im glad you found us in time to make sure
your pan is built properly. It is one of the most critical parts of the
shower to be built right the first time. Best of luck.

imunwell2
02-29-2008, 09:29 AM
I had a tile guy here in Atlanta quote me just to do my shower pan. I did not know it a first, but he was going to do it just the way yours was done. I ask him if he would make two trips to my house or if he would be able to do the pre-slope and pan all in the same day, he didn't have a clue what I was talking about. So, I described it to him and he said he had never heard of a pan being done that way. If I wanted him to do it that way, he'd have to charge me a least double. His original quote was $650. I decided to do it myself. I went with the kerdi system to make my life easier though.

JeanJet
02-29-2008, 10:42 AM
Hello, all, and thank you very much for all of your great information and suggestions.

My contractor proposes to put durock on the curb over the liner, screwing it down on top of the curb. Having done a lot of research in the liberry and of forum posts, I understand the myriad problems of doing so. However, I've spent a fair bit of time this morning calling tile contractors on the "preferred" installer list of the best tile place in atlanta and have yet to find someone who does everything called for in JB's instructions for building a shower pan/curb. Some do parts of the correct method but then muck it up by doing other things that are way incorrect. The chief plumbing inspector for the city has no idea what a preslope is. Argh!!

Does anyone know of a contractor in Atlanta who could do my shower installation correctly? I understand now that I need to have someone do the entire installation rather than just the pan/curb and am willing to do that if I can just find someone. Help!!!

JeanJet
02-29-2008, 12:10 PM
Hi - I'm desperate to find a tile contractor in Atlanta who adheres to the pan/curb construction methods advocate on this forum. References or ideas for locating someone would be enormously appreciated, I'm having zero luck calling even highly recommended local contractors...help!

imunwell2
02-29-2008, 12:12 PM
If you are questioning the process discussed here, you can see the same installation procedure on the oatey website. Here is the link. I wish I could help you with someone here in atlanta, but I couldn't find someone to do mine the way it is supposed to be done, so I decided to go ahead a take it on myself. Another option is to see if you can find someone to do it using the kerdi method. Then, there is only one layer of mortar in the shower, and it is covered with the kerdi membrane. The kerdi system is a bit more expensive, but it made it easier for me mainly because I had a curved curb.oatey shower drain installation (http://www.oatey.com/apps/catalog/instance_assets/assets/How_to_Use/ShowerPanLiner.pdf)

You can see my thread here:My thread (http://johnbridge.com/vbulletin/showthread.php?p=576250#post576250)

cx
03-01-2008, 08:48 AM
You want it done right, Jeannie, do it yourownself. :shades:

JeanJet
04-19-2008, 11:16 AM
Are pre-formed corners necessary when building a curb? Some of the liberry materials say so but a couple of John's tutorials show lath directly over the pvc and then the mud with no pre-formed curb (i.e. wood curb to pvc to lath to mud).

If curbs are sometimes necessary and sometimes not, an explanation of how to know when to use them would be really helpful.

Just want to make sure I get it right, thanks!

Jeannie

Hammy
04-19-2008, 01:11 PM
jeannie, are you still fighting with your GC to do the shower right? Hammy

MudGuy
04-19-2008, 04:55 PM
Hi Jeannie -

Regarding your pan, fold your inside corners and purchase/install your outside corners. Your local plumbing code probably requires the use of outside corners plus they make the transition from wall to curb much easier and watertight.

You need a curb if your pan area is on the same elevation as the rest of the bathroom. If your pan area is recessed, you have the option of going with or without a curb. Since you're building a 3' x 5' shower pan, I would build a curb regardless, to help keep water contained to the shower area. :D

ceramictec
04-19-2008, 05:12 PM
like Jonathan said,

if you have big shower where body spray and water going all over the place you could do curbless, but for a 3x5 you need a cub and a glass enclosure or shower curtain.

JeanJet
04-20-2008, 07:09 PM
UGH - sorry but I mixed up my terms...we're definitely building a curb.

What I meant to ask is:

When are pre-formed corners necessary and when are they not? Some of the liberry materials say to use them but a couple of John's tutorials show lath directly over the pvc and then the mud with no pre-formed corner at all (i.e. wood curb to pvc to lath to mud).

Also, can someone clarify for me what an inside corner is versus what an outside corner is?

Thanks,

sheepish novice

MudGuy
04-20-2008, 07:37 PM
Hi Jeannie -

http://johnbridge.com/mortar_bed_shower_floor.htm , photo's #6, #9 and #15.

Photo #6 details a folded inside corner.
Photo #9 details a outside corner piece that you need to purchase. You need to buy two, one for each side of your curb.
Photo #15 details placement of the outside corner and #16 shows it covered with lath.

JeanJet
04-21-2008, 04:32 PM
Thank you very much!