Hello all,
We are having a marble tile shower built in the new addition and are getting different recomendations from tile installers on construction techninques. Currently the shower area has a backer of greenboard. The three recommendations that we have are
1. Apply a waterproof membrane over the greenboard and then tile.
2. Remove greenboard, install Denshield or similar and tile.
3. Remove greenboard, install tar paper, chicken wire and then mud, tile on top of this.
Which option is best? Is there a fourth superiour option? In order not to bias this scientific study, 🙂 I will not state mine or my wifes preferences.
Thanks in advance for your time.
Scott
Replies
I'v done a few tile jobs as an amateur (not a professional contractor) around the home. One of my current projects is to re-tile a shower that originally had the greenboard as the substrate. It lasted several years, however when the grout started to fail (not very noticeably at first) the water damage became widespread. Now it is all coming out. If you're doing it yourself, I would suggest a concrete backerboard. They are easy to work with and will give you better protection than greenboard. I don't know about the chicken wire solution, but it has to be superior to the greenboard option.
1. Never use Green Board in a shower. The "green" is not, as some think, a water repelleant material but rather an anti-fungus/ bacteria material. After it gets wet 2 or 3 times it is no longer effective. Incedently, now this was told to me be USG, green board is not reccommended for use on ANY ceiling. The green application weekens the structural strength of the board and it MAY sag between fastenings over time.
2. Use only cement board, Durock, Denshield or the equivelent. Never use ANY gypsum product in shower/ tub areas. When gypsum gets wet it looses its structural intergrity. As for the other materials mentioned, if they get wet - something else in your installation failed - at least you won't have to also replace your wall sheathing.
3. The shower pan should turn up the wall for 6"-8" on all four sides and the corners must be FOLDED and NOT CUT!
4. The cement board wall sheathing should be installed 1/2" shy of the FINISHED shower floor and INSIDE the shower pan. This is so a) water from the shower floor cannot wick up the wall sheathing and b) any moisture that does find its way into the wall sheathing just drains itself into the shower pan.
5. Chicken Wire???? Expanded metal lath is the proper term and NO you do not need it. This is for wet wall (vs. drywall) construction. Totally unnecessary and ill-advised for your situation.
Frankie-
Thanks for the response. I meant lath but could not think of that word first thing in the morning (even though the lath installer for stucco took nine days to lath our 800 sq ft addition, I should remember the word lath). They have already "hot mopped" the shower pan (and it has been holding water for days waiting for the inspector). If you use the cement board sheathing, what keeps the water from penetrating to the studs? Is there some sort of water barrier?.
I should be able to look all this up since I bought the Tile Council of America literature about a year and a half ago, but the construction and required elimination of my storage shed has made that impossible to find right now.
Thanks for your help.
Scott
Studs.
Tar paper over the studs, lapped, with the bottom course layed over the membrane.
Cement board over the tar paper, screwed to the studs, held a half-inch above the FINISHED floor.
A drop of water gets throgh the tile, it drains down the tar paper, onto the membrane, never touching the framing.
Where tile planes come together (wall-wall or wall-floor) caulk, don't grout.
Get Michael Byrne's book if you need something more than the TCA book.
Also, there was a pretty good article regarding shower pans in a recent FHB. I don't recall if it was so comprehensive that it discussed walls, or if it was just about floor/pan details.
Also, there was a pretty good article regarding shower pans in a recent FHB. I don't recall if it was so comprehensive that it discussed walls, or if it was just about floor/pan details.
Issue no. 141, September 2001...
Regards,
Rework
4. The cement board wall sheathing should be installed 1/2" shy of the FINISHED shower floor and INSIDE the shower pan. This is so a) water from the shower floor cannot wick up the wall sheathing and b) any moisture that does find its way into the wall sheathing just drains itself into the shower pan.
There is some debate among the manufacturers of the various CBUs on this issue. Some mfg's want the board imbedded in the mud deck, others want it held above the finished floor and then the gap caulked. Make sure that whichever board you use, it's installed according to the manufacturer's current spec, so you don't have any warranty problems. Your installer should have a copy of the installation instructions and be familiar with the warranty info for the product he uses.
Also, if you want maximum waterproofing, look into a liquid waterproofing membrane (such as Laticrete 9235) which is applied by trowel or roller over the backerboard after it's installed, thus providing a completely waterproof surface for the tile. This is a better (and more expensive) solution than tar paper behind the board. If this shower is going to be used a lot then I would make the investment.
Laticrete 9235 is great stuff. Much easier and less toxic than working with lead as for shower pans. Great also for walls in high use areas as you said. But let's clue everyone in to what "high use" areas are. Situations, like waterfall walls, where the wall surface is constantly wet or commercial applications like athletic clubs, gyms, and public baths. Not shower stalls in a family of 5 home. For moisture to permiate through a ceramic or stone tile, then go through the backerboard... and then affect the structure behind without succumming to gravity and draining into the shower pan, we're talking pretty serious heavy use. Ah, but you might say how about through grout lines. Still very little if any gets through especially if you use a modified grout and /or apply two coats of grout sealer.
Either way, the 9235 should not on principle be used to allow one to do sloppy work making the tile assembly to be purely cosmetic. It is specified when even the best tile installation is not adequate. Now we are back to the situations I mentioned above.
Edited 10/30/2002 9:40:22 AM ET by Frankie
Edited 10/30/2002 9:41:33 AM ET by Frankie
Frankie, I'm not sure I agree with you on this one. On a majority of tearouts we find (and a lot of the guys over at http://www.johnbridge.com find) that the backer board or (god forbid) greenboard is soaking wet at the bottom 6 inches even with very moderate use. Tile and grout are surprisingly absorptive... it doesn't take a lot of use to get water/moisture back there.
That said, there's a lot of debate in the trade re: waterproofing membranes on top of the CBU and Mud Bed. Personally, I'm in favor of it. I like the idea of keepng the wall cavities as dry as humanly possible. On one job we did, some settling took place after the fact, and a small hairline crack formed in the floor in the grout lines. I'd be a lot more concerned about that if I hadn't used 9235 on the installation. As it stands now, it's merely cosmetic.
On balance, other's say that a properly constructed pan with preslope and open weep holes in the drain creates a self draining system regardless of how much water wicks behind the tile. That makes sense too. Most GC's and setters in my area wouldn't know a well constructed pan/preslope if it bit them on the a--. I'm in the NE where people are still using copper pans!
Sounds like we're pretty much all in agreement that greenboard is crap, mud jobs -- done by a real pro -- are best, and CBU is good enough for most installations.
_____________________________HomeBase________ Kitchen & Bath Builders, LLC
Brian Roberts, Manager
Edited 10/30/2002 10:55:00 AM ET by homebaseboston
I beleive we are in 100% agreement. But let me point out the mis-inferance.
Grout does fail if it is not maintained, installed properly, or there is movement in the structure. This is why a proper substrate installation ALWAYS has:
1. A copper, lead, composite, PVC, Latiticrete 9235 or their Floor N Wall membrane pan which extends 6"-8" above the FINISHED floor. (Most installers do it 6" above the subfloor. Big mistake.)
2. Non-gypsum walls - cement board or Densheild or equivilent.
3. Wall sheathing which extends into the pan - the membrane is installed first and the sheathing is applied on top of it. You can debate the 1/2" vs. inbed issue all you want. Leave me out. I know what works by doing and not by theory.
4. Proper floor slope - 1/4" per 12".
5. Unobstructed weep holes. Most weep hole clogging occurs during installation rather than during the years of use.
Edited 10/30/2002 12:11:23 PM ET by Frankie
I always use cement board for the bottom"course" of substrate and Denshield from there up. I try to keep a clean factory edge down, and by being extremely meticulous about hanging the cement board, I am able to locate it a the proper elevation that allows me to use the bottom edge as my screed for the mud base at the wall perimeter.
The mud floor is right up to the bottom of the cement board. Tile the floor first then the walls.
Works for me.
Eric
Perhaps I misunderstood. I thought you were saying that high use applications (like waterfalls and gyms) were the only situations that might warrant a membrane. I was just adding that, in my -- also hands on -- experience, traditionally installed CBU showers used as infrequently as 2X per day can collect water at the base of the CBU... and CBU can and does become saturated. I realize that if a moisture barrier such as poly or tarpaper is installed over the studs there is some measure of protection there, but if I had the choice -- and I wasn't worried about the extra $100. for 9235 -- I think it's better protection for the structure. I've had settling/cracking in my grout joints on only one of my jobs, ever, (the one I mentioned), and thank goodness for the 9235 on that one. It was actually only the second time I'd used it at that point. We spend a lot of time heeding your council re: structure and proper deflection... on that point you have my full agreement._____________________________HomeBase________ Kitchen & Bath Builders, LLC
Brian Roberts, Manager
If I reply to your last post we are going to start to split hairs.
However I would like your source for 9235 at $100 a pop. The smallest amount I can buy costs me $450 - $525 depending on where I buy it, plus tax.
Oh, what the hec... Yes, the CBU does get saturated AT THE BASE meaning the lowest 6". This is why we do not use gypsum. The shower pan though, goes up 8" AFF. The CBU is installed within the shower pan. So moisture still does not come into contact with the structure.
Now I don't recall who began this conversation, but I did not get the impresion he/she is a pro. Giving them more work (9235) which also requires: a) another set of skills and knowledge, b) time (think learning curve), c) money (my estimate for materials $500), and d) time required to find the 9235. Not too readily available to the layman.
But if you you recommend 15lb felt - knock yourself out. Have a great time.
In case you had any doubts, this oppertunity for the CBU to become saturated at the base is the reason why I insist on a 1/2" gap between the CBU and the shower finished floor. This way water only moves in one direction - down - and NEVER wicks UP.
Go ahead and have the last word. I'm done.
Okay then, dammit, Frankie I will....
Laticrete makes "Mini Units" for around $100. that I get at my American Olean Dist. They're the perfect size for most showers. I don't use it often enough to justify the expense for the big rolls/jugs, so these are great. Haven't bought one in a few months, but assume they still make em.
:)_____________________________HomeBase________ Kitchen & Bath Builders, LLC
Brian Roberts, Manager
Once again, thanks for all the constructive comments.
We have chosen a tile installer that will remove the greenboard (put in by the drywallers so that we could pass inspection, not sure I agreed with that but I did not want to step in front of the steamroller) and install whatever backer board I purchase. I will have the backer board installed per the manufacturers instructions. I'm not sure which backer board I will get, it depends on availability. I am considering using the Laticrete, but will also look into other options.
For the record, I always was against the greenboard option, but GC and pregnant wife needed to be educated. I wish I could find my TCA handbook, but the house is rather disorganized right now (not to mention my garage).
Now I am not sure if the green board on the wall above the soaking tub should be replaced? Since there is a dedicated shower I do not think that it would be exposed to much moisture. Maybe we could just replace the bottom portion, say 24" or so. Hmmm.
I had always heard that an living through a house addition was stressful. Having a pregnant wife that wants everything done before Dec. 15th due date makes things interesting. She has been awesome with keeping on top of scheduling and such, but it is still stressful. I am finding that my creativity seems to be draining away as the project progresses. Too many choices. Maybe once the new shop is functional it will return! Our GC has been awesome. It's now two months since he started digging the foundation and they finished mudding the drywall yesterday! It has been great to watch the progress even if the engineer in me wishes I could stay home from work and work on the house instead. I made a deal with DW when we started this project that the amount of work that I do is to be severely limited to enable me to spend time with DW and 3 year old daughter.
Thanks again for all the help.
Scott
Outside!
Funny that there is consensus but not agreement. I've read myself to sleep on teh same topic and I don't think anyone is more correct than the other. I'd say read it and use your own logic to determine the right way.
One point not mentioned is to increase the stud wall support in the shower. No matter if it is cardboard or Cement backer board you need to go to 12 inch on center for the shower walls. For the price of a few 2x4x8's you can make non flexing walls. Flex is bad. Grout and Marble will lose their integrity.
As long as you are stripping the green board off. (not a big project) add in more studs and a spot for a handrail or two. When you are young & frisky or old and fragile the hand holds help.
Young and frisky hand hold are used for ankles if there are two in the shower.
16 oc's fine. Never reframed a shower...never had that problem. Jeff..............Al-ways look on......the bright......side of life...........
.......whistle.....whistle.......whistle........
If you think of your wife and expected as motivation, as you are, then you can also explain to them that doing things right will give you so much more hassle free time to appreciate each other later.
Then again, I think you already figured that out!
In other words, for a few extra bucks, overbuild.
Owwww!
I just called a local midwestern source for this stuff from the laticrete.com website. List price for the goop is over 750 bucks for a pail. A five gallon pail of this stuff costs $550 with a contractor discount and we haven't even talked about the fabric that is used. I guess it is made for the shower cause you have to grab your ankles to use it.
I'm going to search this thread to see if there are alternate products available because the design idea sounds like a good thing. I was planning to use the std plastic barrier (compo blue or whatever) but you threw out this as a good alternative. I just don't think I can swing the $ for that level of security.
By the way, what do you use to hold the membrane in place on the pre pan? Thinset? Hot mop? Roofing adhesive? You need something to hold the plastic in place when you form the pan that holds the tile don't you?
Booch,
Most of the Home Centers have a "mini" version of the Laticrete 9235 called Floors and Walls, and it comes in a 2 gal package for about $80, which is enough to do a small shower.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
By the way, what do you use to hold the membrane in place on the pre pan? Thinset? Hot mop? Roofing adhesive? You need something to hold the plastic in place when you form the pan that holds the tile don't you?
I assume you're talking about the shower pan (in the floor, vs the waterproofing for the walls)? I coat the preslope and about 8" up the walls with roofing cement, then install the membrane, then staple the top 1" of the membrane to the walls.
Now back to waterproofing the walls... there are other similar products out there besides Laticrete, I think Custom Building Products and Mapei both make a trowel on membrane (the Laticrete is readily available in my area, so that's what I've used). If you can't swing the $$, then 6 mil poly behind the studs is an alternative. I would seal the seams and over fasteners with roofing cement prior to hanging the backerboard. Or, you may consider a product like Dens Shield or foam-based Wedi board, which have integrated waterproofing.
If this is going to be a heavy-use shower, a liquid membrane over the board is still the best option...
Edited 11/5/2002 6:38:59 PM ET by AndyL
"about 8" up the walls with roofing cement, then install the membrane"
That is my plan. I assume there is no issue with the membrane and the roofing cement having a chemical breakdown issue.
Further, the thinset I plan to use (premixed in a bucket latex modified) is compatable with the roofing cement?
I know few here play a chemist on TV but have you seen any problems with the bond? I just want it to stick and stay.
"Custom Building Products and Mapei both make a trowel on membrane "
I'll look for these two. It has to be a tough design issue to make something impermable with tooth for hard and crusty thinset as well as flexible to absorb secured building movement.
That is my plan. I assume there is no issue with the membrane and the roofing cement having a chemical breakdown issue.
Depends on the membrane I suppose. I use CPE membranes (Noble brand) for shower pans, so I use the roofing cement beneath the pan to hold it in place. The roofing cement is applied directly over the cured pre-float, before the final mud bed (the thick part) is floated, so it never comes in contact with thinset. Any moisture that gets through the tile and mud bed, should hit the pan and flow to the drain through the weep holes. There is an excellent discussion of this in a FHB article from maybe a year and a half ago. Also, there is a discussion of this in Michael Byrne's book "Setting Tile", which is what I based my procedures on.
It has to be a tough design issue to make something impermable with tooth for hard and crusty thinset as well as flexible to absorb secured building movement.
I'm no chemist either, but it's my understanding that this is why these liquid membranes work so well. Many are also crack-isolation membranes as well as waterproofing membranes, which makes them an excellent choice over slabs. I always read the mfg's instructions carefully before selecting a product I've never used, and most mfg's have provided excellent service when I have questions about applications of their product. Let us know how it works..
Got it understood. Thanks. It is kind of like getting dressed for skiing but using glue to keep your shirt tail down. ;-)
Funny thing about Michael Byrne's book is his use of 3-2x4's sandwiched to make a curb. Doesn't look good in my mind having a thin crust of concrete over a moving substrate. I'm making a solid curb instead. Chickenwire and the membrane should be solid enough for that.
Andy:
Do you have any experience with Laticrete Watertight? According to their datasheet:
LATICRETE Watertight Floor N’ Wall Waterproofing is a liquid applied waterproof membrane for direct use under installations of ceramic tile, stone, brick and other finishes. Recommended for floors, walls and ceilings in wet areas such as kitchens, bathrooms and showers. Suitable for Residential and Light Commercial applications. For Industrial, heavy duty commercial and continuous underwater submersion applications, use LATICRETE 9235 Waterproofing Membrane.
I'm checking into the price, it may less expensive than the 9235
Booch:
Some misconceptions may have developed.
First, the PVC or CPE membrane does not have to be bonded. Not at all. Lay it in there and staple it at least 4 inches above the curb line. Now that having been said, some guys do bond their pans. Some only to the blocking (like Andy) and others bond to the pre-slope as well. I bond only to the blocking and here is why. Spreading the pans out and getting them flat without wrinkles can be a chore. If left un bonded, the weight of the mortar will flatten them out. Bonding them to the pre-slope may actually cause wrinkles.
If you decide to bond the pan membrane to either, use a recommended adhesive. For PVC I use roofing cement or Butyl caulk. I think the caulk is easier to apply but pricer. For CPE, I think Nobel recommends Nobelseal 150, a very pricey $18 a tube form of butyl caulk.
Second, do not use a pre-mixed thinset. Jeez, the bagged stuff is so easy to mix and so cheap ($15 a bag), and the pre-mixed stuff is such c r a p and so expensive, that you should avoid it at all costs.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
Speaking, as a guy that just smutzed my shirt with marinara sauce while eating a sandwich at lunch today, I try to avoid mixing anything I can. I spend too much of my time in cleanup. However, you might have shamed me into doing the mixing. Speaking of that, do you put in the liquid additives? I haven't taken more than a passing glance at the jugs and the bags of mix. This is all indoor obviously and the area will be heated so I don't think there are many conditionals I need prepare for.
As for the mixing. I spent summers in highschool mixing Thoroseal with water. There are times I thought it was vaseline it took so long for it to get saturated. That swimming pool topcoating material really soured me to mixing. It sounds like the thinset is easier to mix up.
I take it the barrier PVC or CPE (mine is grey so probably PVC) doesn't pose a bonding problem for the floating chunk of the final slope of mortar. Roofing cement I bought is the 1 gallon black goopy stuff. (you know the non-asbestos fiber reinforced roofing cement) As much trouble as it is to clean up after that I may go your route on the Butyl caulk. I'm a couple weekends from the PVC pan and Top form so it's time to shop for the right stuff.
You are all right! Thanks
The thinset I use is Custom's Versabond. Not the most expensive, but it is a high end thinset with all the additives already in it. Comes in grey or white, and white is a buck more a bag. Total cost is about $15 a bag. Get a good drill and a mixing paddle and you can mix up a bucket in about 3 minutes. Let it slake, or rest, for about 10 minutes, then re-stir it. I mix it thick so a dollop will not fall off your finger.
No, the PVC/CPE will not present bonding issues for the final setting bed. Indeed one wants the setting bed to float ontop of the membrane. I just bond the membrane to the wooden blocking. Make sure you caulk the joint between the 2 part clamping drain and the membrane on the bottom of the membrane. If you caulk it on top, you may clog the weep holes. Get a good cast iron clamping drain if you can find it, not one of those wimpy Oately PVC ones. However, I wouldn't be surprised if that is all you can find, and thats OK.
Here is a link to a reference library where you can find answers to most of your questions. http://www.johnbridge.com/vbulletin/forumdisplay.php?forumid=8&daysprune=
Good Luck, Booch!Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
Often ignorance is more comfortable. This level of information is great but I can find several things that should be of concern. Subfloor layup, Floor joist spacing, Corner treatment... It goes on and on. Sometimes I just gotta do the job and give up on perfection.
In truth the best way to build a tile shower is to start with that concept before you dig the foundation for the house. Yes, I got the L360 support however it is made on 24 inch centers with 1-1/8 tongue & groove gold edge OSB (beaver barf) subfloor. Thinset & screwed 1/2 inch durock covering to hell and gone. and of course the white PVC Oatley (or whatever the tile shop had) clamp drain. (whimsically designed bit of plumbing stuff)
I thought I was hot doodoo when I put in a plumbing coridor in the floor joists (First joist after the rim is at 1' OC then back to the standard 2' OC) Now it seems the buck two fifty I saved by not throwing in a couple more Floor joists would have make me more confident in the security of the Porcelain floor tile. I'm sure it will fly just fine but it'll be something to watch for the next 30 years.
That johnbridge site is extraordinarily helpful. That and the Tile setting book cover all the bases.
You's alright Boris. say Hi to Natasha. Oops your first wife before the name change eh?
Boris,
Just bought 4 bags of your wonder mud and a drill spinner for the floor tile project this weekend. I'm spread over many projects, this will occupy the wife & the eldest while I play Michelangelo on the drywall joints in the rest of the place. If time, I'm thinking I'll go up to attach and fit the shower pan. Still looking for the Butyl caulk. I went to HD at lunch and looked in three areas but couldn't find it. I may have to go to a different source.
Say hi to our old russian buddy in the leper ward, Shriveup Andropove!
Thanks for the wake-up call on the premix.
HD has it with their other caulk, usually in the paint department. They have two different kinds, and I think either would work for tiling.Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
I looked in that department but got rattled by someone's crying kid in a cart and only had a few minutes at that point. Had to study the Versabond. got lost in the details. Must be a lot of spanish speaking tilesetters. Equal time in the labeling. Quebec must be miffed, no french on the bag. Probably have to make it an 80 lb bag to get all the languages on it I suppose.
Butyl caulk may be ynder the brand name PL....
And don't only go by description. Readthe product sub title.
PL is only at menards, HD has some other brand. No butyl there. I just spent 30 more minutes of my life figuring out their inventory. I'm going with roofing cement. I have that.
The HD in my area is not only stocking Quad and PL now, but also Vulchem. It appears someone finally clued them in to what good caulk is.....
Might have been vulchem I saw .... came in a gold tube and looked to be a silvery caulk that was used in eaves trough joints. Funny, Butyl was never mentioned in the ingredients. Only rubber was thermoset rubber at about 30 percent content. Otherwise no butyl caulk.
I just installed 650 sq ft of porcelain floor tile this weekend. got real familiar with mixing thinset and kneeling on durock. Thank God for the MD diamond wheel tile cutter. Probably 1/3 were cut pieces.
Probably Thanksgiving or better before the shower gets setup."The time has come" the walrus said. "To talk of many things, to talk of ships and sealing wax and cabbages and kings, and why the sea is boiling hot and whether pigs have wings"
"... then 6 mil poly behind the studs".
you mean between the studs and cbu, correct???
brian
I'm kinda wondering if this isnt to excess. The lengths you may go. I've done walls with wonderboard and a mud shower base. Then I tiled the walls, ceiling and floor with green marble in a nice sized shower I built with marble seat and all. It was heavily used for about ten years by myself, my wife and kid. I never had any issues what so ever.
Be well
NAmaste'
Andy
It's not who's right, it's who's left ~ http://CLIFFORDRENOVATIONS.COM
Edited 11/7/2002 7:14:03 AM ET by Andy Clifford(Andybuildz)
"The three recommendations that we have are 1. Apply a waterproof membrane over the greenboard and then tile. 2. Remove greenboard, install Denshield or similar and tile. 3. Remove greenboard, install tar paper, chicken wire and then mud, tile on top of this.
1. Option One is ridiculous. Gypsun has no place in the shower. Run from this guy.
2. Option Two is not bad. I would stay away from Denshiled and instead use Hardibacker, Durock, or Wonderboard. This is fine for walls. Marble is very soft and will crack unless the setting bed is dead flat. Not a big issue on walls, but stay away from inferior installations on floors.
3. Option Three sounds like an old time quality tile setter. If done right, it will be dead flat, strong and perfect. There is no better setting bed that mud.
Hot mops? Wow, you must be from California. We are the only state that still uses them. Make sure the weep holes in the drain (3 little holes along the outside are clear and clean and work. Make sure there is a pre-slope, e.g., that the hot mop is over a sloped mortar bed.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
I agree with Boris pretty much word for word.
If I bid the job....I'd be the demo then backer board guy.......not opting for idea No.3 because I started tiling for cash after CBU hit the market..and I never learned the old time way of doing things........
And with something like tile...older might be better. If the numbers kinda match.....I'd be inclined to go the route of the full mud job....if the guy seems like he can handle it.
Much more of an art than tiling over backer.
That said.....I get my work based mostly on my layout and finished product quality......so the old guys full mud job might last over 100 yrs.....with my backerboard job lasting only 99.......but I might be able to provide the better looking of the two.
Pick the best guy outta the No 2 and No 3 bids. Jeff..............Al-ways look on......the bright......side of life...........
.......whistle.....whistle.......whistle........
Never been a tilesetter, but in my trade I have worked around, and watched, many of them. My uneducated observations ...
A good mudsetter can plumb the shower stall walls dead nuts, and probably faster than most people could get the studs or backer board shimmed plumb (gotta be plumb, or your corner joints look like hell).
A musdet surface is more resistant to an errant elbow banging against it than just backerboard. You're less likely to jar grout lines loose over time.
I think this is a good trick ... one mudsetter leaves the pan free of mud until after he's tiled the walls. This allows him to bring the mud in the pan up exactly parallel to, and the right distance from, the wall tile, so that when he's done tilling the pan, he's got a perfectly even look all around.