Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Welcome to John Bridge / Tile Your World, the friendliest DIY Forum on the Internet


Advertiser Directory
JohnBridge.com Home
Buy John Bridge's Books

Go Back   Ceramic Tile Advice Forums - John Bridge Ceramic Tile > Tile & Stone Forums > Tile Forum/Advice Board

Sponsors


Reply
 
Thread Tools Search this Thread
Old 11-04-2017, 11:45 AM   #1
b667
Registered User
 
Join Date: Nov 2017
Posts: 6
On Slab Curbless Shower, Odd shaped

Hi All! New to this forum, non-pro but I've done several projects with the help of other forums (namely "floors transformed" which seems to be dead). I like to do my projects by the (TCNA) book and have done 2 square curbed showers and over 1K sqft of tile.

So I busted out my master bath shower which was cement board walls, mud bed, no drain flange or moisture barrier whatsoever. I had noticed water damage to adjoining half walls and slight browning of the floor molding on the opposite wall. The wall tile appeared to have been set with some fort of mastic the color of liquid nails when dry. House is Late 2003, PT sill wood and framing had obvious water contact but still in good shape.

I want to use a integrated Laticrete Bonding flange to avoid a pre-slope, liner then slope. The 2015 Notable changes of the TCNA page "New Curbless Shower Methods" Figure B422C illustrates what I am trying to accomplish. IF you look up the laticrete hydroban bonding flange you can get more info on youtube/web. The gist of it is install the drain, deck mud sloped, hydroban over mud, wallboard and flange, tile over the completely waterproofed surface.

So for the Mud bed laticrete instructs use of the 3701 Fortified Mortar Bed, around $26 a 60lb bag. This being a curb-less shower has thrown me off; so many questions.

#1 Bonded or Unbonded Mortar Bed? (says to used 254 Platinum as "Slurry Bond Coat" if bonded)
#2 Places where I have to feather to the main bathroom floor - do I use thinset for the last 1/2 of depth (to feather)
#3 wallboard debate - Hardibacker first and mud bed up to it or mud bed then hardibacker with small gap (avoid wicking) - not sure where TCNA stands on this
#4 All the other details I am forgetting. Any tips?

Looking forward to learning something!

David
Attached Images
  
b667 is offline   Reply With Quote
Sponsored Links
Old 11-04-2017, 12:59 PM   #2
Lazarus
Texas Tile Contractor
 
Lazarus's Avatar
 
Join Date: Oct 2006
Location: Beaumont, Texas
Posts: 7,279
Whenever setting a shower mud bed, I always use a slurry coat of thinset to bond it. Frankly, any decent modified thinset is just fine. 254 is a bit pricier, so Versabond will work quite well.

Hardibacker should be put in after the bed and held just above the mud.
__________________
Laz...

“Everything in excess! To enjoy the flavor of life, take big bites. Moderation is for monks.”
Lazarus is online now   Reply With Quote
Old 11-04-2017, 06:43 PM   #3
jadnashua
Veteran DIYer- Schluterville Graduate

STAR Senior Contributor

 
Join Date: Jul 2004
Location: Nashua, NH
Posts: 11,721
IF you're going to use a sheet membrane, you can use plain drywall with either Schluter's Kerdi or Laticrete's Hydroban...both have been tested and certified for use over it (and other backing materials). Because you're going to be applying a waterproofing sheet over it, if you want to use HardieBacker, you could embed it in the mudbed. FWIW, there are two classes of cbu: fiber-cement, and cement. In a conventional shower, you cannot embed fiber-cement products into the mudbed, but it shouldn't matter with a sheet membrane. Note that of the cbu's out there, Hardibacker is probably the thirstiest one out there, and you must thoroughly wet it before spreading thinset, or it will suck the stuff dry before you can embed the sheet material over it. Lots of people complain about that. Plain drywall is easier, larger sheets, fewer seams, easier to cut, and works just fine in this application. You still want to wet sponge it before spreading the thinset.
__________________
Jim DeBruycker
Not a pro, multiple Schluter Workshops (Schluterville and 2013 and 2014 at Schluter Headquarters), Mapei Training 2014, Laticrete Workshop 2014, Custom Building Products Workshop 2015, and Longtime Forum Participant.
jadnashua is offline   Reply With Quote
Old 11-06-2017, 10:19 AM   #4
b667
Registered User
 
Join Date: Nov 2017
Posts: 6
Thanks for the replies gentlemen. Bonded sounds like a good idea considering this is curbless. I don't want a crack where my mud bed begins.

So reading up in the laticrete docs I came across spec stating "Mortar beds shall be 3/4 min to 2" Max". Mortar beds in excess of 2" thick shall be detailed by the architect per TCNA F112.

Anyone familiar? Can I do a 4:1 standard mud bed with a fortifier "milk" instead of water?

The flange must be min 1.25" above the slab but my mud bed will have to be almost 3.75" at the outer edges.
__________________
David
b667 is offline   Reply With Quote
Old 11-06-2017, 10:32 AM   #5
cx
da Home-builder -- Moderator-at-Large
 
cx's Avatar
 
Join Date: Jul 2001
Location: Boerne, Texas
Posts: 85,157
Welcome, David.

You can set your bonding flange drain 3/4" above your slab and still be able to force your deck mud under it easily enough.

Make the height at the perimeter whatever it needs to be without concern about any two-inch "maximum" height. For a shower floor it's not a problem at all.

I would recommend a simple mix of 5:1 sand to Portland cement mixed with water. You get into putting leche in the mix and you start getting sticky and difficult to work and you don't need it at all for a shower floor. You can make a 4:1 mix if that makes you more comfortable, but it's not necessary.

I recommend the USG Durock Shower System membrane with the associated bonding flange drain. All available on Amazon. All you need is the drain and the sheet membrane.

My opinion; worth price charged.
__________________
CX

Y'ALL NEW VISITORS READ THIS HERE!
cx is offline   Reply With Quote
Old 11-06-2017, 11:09 AM   #6
Sharon @ LATICRETE
Registered User
 
Sharon @ LATICRETE's Avatar
 
Join Date: Sep 2015
Location: Bethany, CT
Posts: 198
Hi David - I'd encourage you also to give our Tech team a call...they can walk you through the details of your specific install using LATICRETE products and help to answer any of your questions. They can be reached at 1.800.243.4788.
__________________
Sharon@LATICRETE
Sharon @ LATICRETE is offline   Reply With Quote
Old 11-06-2017, 12:27 PM   #7
b667
Registered User
 
Join Date: Nov 2017
Posts: 6
THanks CX

I'm going the Laticrete way because I've had good success with them in the past. Funny enough I think I found them at Lowes where they use to sell their product.

I'm assuming they want to Latex in there to stick to the PVC of the flange even though it already has the keyed polygons around the perimeter - I'm no expert though. So you say do the 5:1 and thinset to bond it or unbonded?

Sharon, I do better having it written out for me; I read a lot faster than I can talk. Would be great to have laticrete tech answer some questions here that could possibly help others (not just me).

The only think I think odd about the drain is that the femail threaded drain insert bonds to the flange itself - leaving lots of room to get the drain off center - threads should be in the bonded flange for simplicity

Thanks All
__________________
David
b667 is offline   Reply With Quote
Old 11-06-2017, 03:48 PM   #8
Sharon @ LATICRETE
Registered User
 
Sharon @ LATICRETE's Avatar
 
Join Date: Sep 2015
Location: Bethany, CT
Posts: 198
Smile

Quote:
Sharon, I do better having it written out for me; I read a lot faster than I can talk. Would be great to have laticrete tech answer some questions here that could possibly help others (not just me).
Hi David - I've sent this over to them and will post a response for you as soon as I receive it
__________________
Sharon@LATICRETE
Sharon @ LATICRETE is offline   Reply With Quote
Old 11-07-2017, 07:50 AM   #9
Sharon @ LATICRETE
Registered User
 
Sharon @ LATICRETE's Avatar
 
Join Date: Sep 2015
Location: Bethany, CT
Posts: 198
David - here's the answer from our Tech Team:

1- If going over the old pre-slopped mud bed, we would recommend a bonded application with a slurry bond coat of 254 Platinum.
2- A bonded mud bed application will allow the 3701 Fortified Mortar bed to be ramped down to almost a feather edge (the size of the aggregate being the only limit here).
3- Typically, the cement backer board would be installed first, then the mud bed right up to it
__________________
Sharon@LATICRETE
Sharon @ LATICRETE is offline   Reply With Quote
Old 12-05-2017, 10:09 PM   #10
b667
Registered User
 
Join Date: Nov 2017
Posts: 6
Update - And More Questions

So after recovering from some unplanned back surgery - I'm back on this project

I am paranoid about getting my slope near perfect with this odd shape shower. I took some mason line and ran from drain to corners. At the ends I tied some loops and attached to my corners via rubber bands. This makes it easy to remove and replace as needed and gives me a few lines to follow - most importantly my long 4+ foot line. What do you guys think

The other thing is making sure I have enough mud and thinset - I bought 12, 60lb bags of mud mix (figure I'd save a bit of time mixing the 5:1) and the price is very close. my best guess is to measure volume like a couple rectangles and divide by two (triangle)?

I'm using modified thinset to bond the mud. plan is to start at perimeter, do refernce lines and then fill in between?

Then from what I understand it needs to dry for at least 5 days before I can hydroban it all?

Edit: upload flipped my pics funny directions (sorry). Blue line I drew on pic shows where slope begins

I have to forgo the specific laticrete thinset and mud because its insanely expensive for what it is and special order at my tile shops (meaning it will cost me to return any extra)

Attaching some pics for your viewing pleasure
Attached Images
    
__________________
David

Last edited by b667; 12-05-2017 at 10:12 PM. Reason: Upload flipped my pics
b667 is offline   Reply With Quote
Old 12-05-2017, 10:14 PM   #11
b667
Registered User
 
Join Date: Nov 2017
Posts: 6
one more closeup of my rubber band mason line "patent pending system" lol
Attached Images
 
__________________
David
b667 is offline   Reply With Quote
Old 12-05-2017, 10:17 PM   #12
b667
Registered User
 
Join Date: Nov 2017
Posts: 6
Hardibacker question

I knew I forgot something...

Regarding Hardibacker - specs say to gap panels. But then TCNA says to mesh tape and fill gaps with thinset. am I misunderstanding but doesn't the thinset get rid of the gap (no more expansion joint)?
__________________
David
b667 is offline   Reply With Quote
Old 12-05-2017, 10:57 PM   #13
Houston Remodeler
Pondering retirement daily

STAR Senior Contributor

 
Houston Remodeler's Avatar
 
Join Date: Oct 2009
Location: Houston Texas
Posts: 27,447
The needed gap is so that they are not butted and thus not monolithic. The gap allows the thinset to get in between not just on top.
__________________
Paul1

For when DIY isn't such a good idea...
Houston TX area Kitchen & Bath Remodeling


http://CabotAndRowe.com
Houston Remodeler is offline   Reply With Quote
Reply

Stonetooling.com   Tile-Assn.com   National Gypsum Permabase


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
lowering a slab for curbless shower Houston Remodeler Professionals' Hangout 33 11-18-2014 10:00 AM
Curbless shower pan in slab enormis Tile Forum/Advice Board 11 08-13-2013 10:38 PM
recessed slab for curbless shower on slab wakaru8 Tile Forum/Advice Board 4 05-26-2013 03:08 PM
Curbless shower slab construction rhoff Tile Forum/Advice Board 6 05-12-2009 01:42 AM
Curbless shower on Slab? noel256 Tile Forum/Advice Board 1 07-12-2007 01:49 PM


All times are GMT -6. The time now is 10:36 AM.


Sponsors

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2014 John Bridge & Associates, LLC