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 > Professionals' Hangout

Sponsors


Reply
Thread Tools Search this Thread
Unread 06-09-2001, 07:37 AM   #1
chip
Travelin' Salesman
 
Join Date: May 2001
Posts: 1,088
John,

Here we go!!!

I understand to a point, your contention about deflection.

Util-A-Crete cement backer board is manufactured be Fin-Pan.

Bonsal markets this product and does not manufacture it. I sometimes talk possesevily, when it comes to products that we market for various manufacturers and I appologize for the confusion.

Fin-Pan was the original manufacturer of Wonder Board. Those of you who have been around in the trade since the '70's & '80's may recall that Wonder Board used to be a very hard board with a tighter mesh.

That is what Util-A-Crete is today.

Fin-Pan had instances in the early '90's of fractures to tile and stone, and found that when the board is adhered to the substrate with latex or multi-purpose thin set, expansion and or contraction of the substrate can and will, cause a crack in the thin set leveling coat to carry up through the board and thin set and tile. The crack is very fine, due the mesh pulling it back together.

So they did field tests and with the assistance of the Tile Council of America, changed the specification for the installtion of cement backer board to be installed with a dry set mortar as a leveling coat, and dry set or latex/polymer modified thin set under the tile.

Just like in your mud jobs John, when you put a cleavage membrane between you lath and the substate you have isolated your installation from the substrate. When you do put a cleavage membrane in place, are you concerned about deflection?

I know that I will never make all of you believe that this is the way to go, but I can assure you if you use this method with our (sorry, Fin-Pans) backer board, you will save money (dry set thin set is inexpensive!!) and you will never have a failure. And if you use Bonsal, we won't make as much money sellin you dry set mortar. We aren't as dumb as I look, some people would tell you that would be impossible any way (but they know me better than you). We just want to make you succesfull.

Art Phenis
__________________
Never did it, just know what I read or was told.
chip is offline   Reply With Quote
Sponsored Links
Unread 06-09-2001, 08:52 AM   #2
kalford
Tennessee Tile Man
 
Join Date: May 2001
Location: Newbern,Tn.
Posts: 343
Send a message via Yahoo to kalford
There is a perfect example of what I said in the previous topic.The TCA says;"Dryset OR Latex Modified Thinset"

Obviously stradling the fence and leaving the ultimate choice and responsibility squarely on the shoulders of the installer!!

You will NEVER catch me using regular Dryset to install tile and not even my beloved TEC.

Set your tile with it and I can pop it up with only a pointer and minimum effort....I've done it!!!

I know someone who installs that way and I can name failures....BIG failures as a result of using Dryset to set the tile.

Keith Alford
"Install it Right or Stay Home"
kalford is offline   Reply With Quote
Unread 06-09-2001, 09:06 AM   #3
chip
Travelin' Salesman
 
Join Date: May 2001
Posts: 1,088
Kalford,

I'm with you on the latex/polymer modified thin set issue.

But honestly the vast majority of clay bodied tile set in the state of Florida, is set with dry set mortar.

The state of Floridas consumption of Ceramic tile is in the top 3 nationally. So that means alot of tile installations are succesfull using dry set mortar.

We will always reccomend using the best thin set you can as cheap insurance for a successful installation.

But as we detailed in previous discussions, dry set mortar will absorb into properly prepared cement and tile and harden around the sand/aggegate and create a mechanical bond.

If it didn't work, how many floors could contractors, builders and manufacturers eat and stay in business.

Do I reccomend floor thin set/dry set mortar? Yes, but would I suggest you use a better product? Absolutely!!!!!!!

Please understand that I believe you are doing the right thing. But before latex/polymer additives were available, did all tile installations fail? The majority? 1/2? 1/10? No because cement will mechanically bond to cement and clay.

Art

[Edited by flatile on 06-09-2001 at 11:09 AM]
__________________
Never did it, just know what I read or was told.
chip is offline   Reply With Quote
Unread 06-09-2001, 09:16 AM   #4
LDavis
Texas Floor Man
 
LDavis's Avatar
 
Join Date: May 2001
Location: Canyon Lake, Tx
Posts: 296
Flatile, nice review of TCA recommendations. Kalford, slow down on the read. TCA says dry-set only as the leveling bed mortar between the CBU and the plywood. Latex/polymer modified thinset for adhering tiles to CBU. The nails/screws adhere the CBU to the subfloor, not the thinset. Thinset is STRICTLY a leveling bed to function as additional support to the CBU and help even out irregularities in the existing subfloor.

Unless 1/2" CBU will help even out a transition height difference, I always use 1/4" for floor applications. If the subfloor is not "beefy" enough to support a tile installation, the extra 1/4" of CBU won't make the "saving" difference.

A CBU is not a mud job, but it does seem to be the majortiy of the future at this time. Do it like the manufacturers say and you are CYA!
LDavis is offline   Reply With Quote
Unread 06-09-2001, 09:32 AM   #5
chip
Travelin' Salesman
 
Join Date: May 2001
Posts: 1,088
LDavis,

Thanks for your input!!

1/4" backer board is ok, but you probably have noticed the cost differential is minimal.

The additional 1/4", if clearance is available, is reccomended for additonal strength.

1/4" was brought to market for light traffic areas with transition issues and for counter top application.

Will 1/4" work? Yes.

Should you use 1/2" when you can? Absolutely

I still can't believe I found someone out there who agrees with me!!!!!!!!

Thanks again,

Art Phenis
__________________
Never did it, just know what I read or was told.
chip is offline   Reply With Quote
Unread 06-09-2001, 09:51 AM   #6
kalford
Tennessee Tile Man
 
Join Date: May 2001
Location: Newbern,Tn.
Posts: 343
Send a message via Yahoo to kalford
Hey John,
Maybe you're onto something "sticking" to mud.LOL

LDavis,I too use 1/4" cement board on floors in alot of cases.I do alot of remodels and height is almost always an issue.1/2" on open wall-studs, 1/4" over drywall/greenboard.I try to steer the customer away from installing tile on greenboard around a tub/shower.It'll last for years but the backer will last for even more years.

O.K. I finally see your point about the support on the floor for the backer.My wife has the same problem with me.I'm not easy to convince.One question.Is shrinkage not an issue with the dryset?

Keith Alford
"I know everythang...I just can't remember all of it"
kalford is offline   Reply With Quote
Unread 06-09-2001, 10:02 AM   #7
LDavis
Texas Floor Man
 
LDavis's Avatar
 
Join Date: May 2001
Location: Canyon Lake, Tx
Posts: 296
Flatile, you are right, the cost difference between 1/4 and 1/2 CBU is minimal. Depending on the manufacturer, weight difference is significant. Especially when it comes to hauling those "bad boys" upstairs. (Wheres my backbelt and truss!)

Now your gonna open up that "can of worms" about the structural support a CBU does or doesn't offer in a floor installation application. I'm with you technically, if a 1/4" is good, surely 1/2" is better. (Wall applications anything less than 1/2" is out of the question) Does any manufacturer actually endorse 1/2" as structurally superior for floor applications?

Always willing to learn something new and helpful.
LDavis is offline   Reply With Quote
Unread 06-09-2001, 10:05 AM   #8
chip
Travelin' Salesman
 
Join Date: May 2001
Posts: 1,088
Kalford,

Shrinkage is not an issue in this application.

You will still have a good layer of mortar between the substrate and the board.

If you are using Full Flex, at about $17.00+ a bag compared to $4.00 to $5.00 a bag, you will be more competitive and be able to put a little more jingle in your pocket at the end of the week. Month. Year.

Obviouvly you guys can't pull yourselfs away from the computer today either? I'm addicted, any body have a # for the local chapter of CAA. I just gotta have my fix!!!!!

Have a great week-end, my wife is due home any minute and is going to make me go to the beach. What a drag, 90% naked woman all around, taking there clothes off. It's like a curse, it happens to me all the time. H E L P !!!!!!!!!!!

TALK TO YOU SOON,

Art
__________________
Never did it, just know what I read or was told.
chip is offline   Reply With Quote
Unread 06-09-2001, 10:10 AM   #9
LDavis
Texas Floor Man
 
LDavis's Avatar
 
Join Date: May 2001
Location: Canyon Lake, Tx
Posts: 296
Kalford, unless the shrinkage is "south of the belt buckle", I don't think its a consideration here. Like John has said (I think it was John), functions as a sort of slip sheet or dare I say "uncoupling" device.

I know, if its nailed/screwed, what uncoupling? Thats why I'm here too, gimme some more EDUMACATION please....somebody.
LDavis is offline   Reply With Quote
Unread 06-09-2001, 10:28 AM   #10
kalford
Tennessee Tile Man
 
Join Date: May 2001
Location: Newbern,Tn.
Posts: 343
Send a message via Yahoo to kalford
Yeah,I just don't get it.
Latex thinset holds it's integrity even under adverse conditions.Ever tried to clean it off of a tool after it has set? Let me tell you...it don't "crack" like dryset will! That's why I have a hard time picturing it cracking under backer and that crack carrying through to the tile.I won't buy that unless I see it myself.

Art,my wife is yellin at me to get off the internet.Yes,I have fond memories of the scantily clad ladies of the deep south........did I mention that I'll be making that trip alone?
kalford is offline   Reply With Quote
Unread 06-09-2001, 10:45 AM   #11
chip
Travelin' Salesman
 
Join Date: May 2001
Posts: 1,088
Keith,

I know, I know. I said good bye already, but my wife isn't home yet.

So I'm glad you haven't experienced what I am talking about and do it our way and you never will.

Unless you are opposed to saving money?

I understand they have some great beaches in Jacksonville.

Oh,Oh my wife just got home.

I'm in trouble big time.

see ya.

Art
__________________
Never did it, just know what I read or was told.
chip is offline   Reply With Quote
Unread 06-09-2001, 01:48 PM   #12
kalford
Tennessee Tile Man
 
Join Date: May 2001
Location: Newbern,Tn.
Posts: 343
Send a message via Yahoo to kalford
The beaches from Mayport Naval Base(Hanna-Park) through jax beach south to just above st. augustine are really nice.
Hanna Park was built after a huricane destroyed that area in the early 70's.They made a nice park out of it.In the late 60's to about 1973 you could drive right out on the beaches at jax but it was destroying the dunes so they stopped it.

Keith Alford
"Hire some help.............go to the beach"
kalford is offline   Reply With Quote
Unread 06-09-2001, 02:02 PM   #13
John Bridge
Mudmeister
 
Join Date: Mar 2001
Location: Rosanky, Texas
Posts: 68,125
Send a message via AIM to John Bridge
Well you guys have all confused me on one minor point. Back when I was writing my book, I had a guy who was very familiar with industry terms review the manuscript. One of the things he corrected me on was the use of the term "thin set." Thin set is the method of installation, as opposed to thick set, which is a mud bed.

Dry set mortar, he told me, is what I really meant when I referred to the concrete adhesive material (yes, dry set/thin set is concrete).

Nowadays, everybody uses the term thin set to describe an adhesive, but now you guys are differentiating between "dry set" and "thin set." It seems to me this is still incorrect. All of the concrete adhesives are "dry set mortar," whether they contain polymers or not. And "thin set" is still a technical term for a method of installation.

Unless I'm wrong. It's happened before.

In any case, around here the tile supplies just sell "thin set." It's either modified or it's not. If you go in and order "dry set," you'll get a vague look. Of course, you get that a lot around tile supplies anyway.
John Bridge is offline   Reply With Quote
Unread 06-09-2001, 02:11 PM   #14
kalford
Tennessee Tile Man
 
Join Date: May 2001
Location: Newbern,Tn.
Posts: 343
Send a message via Yahoo to kalford
You're right John. It's just easier to say "dryset" to refer to non-modified thinset and "thinset" to refer to modified dryset instead of typing "latex modified" each time.......................I think.

I still have a problem with NOT wanting to bond the backer to the floor.What about Ditra or the like? A layer of Ditra and thinset is about 1/4" thick...maybe 3/8". There is no way that would be "stiff" enough to support a tile floor without being "bonded" to the floor.Right?Wrong?
__________________
Keith Alford
"I didn't do it...even if I did,you can't prove it"
kalford is offline   Reply With Quote
Unread 06-09-2001, 02:18 PM   #15
John Bridge
Mudmeister
 
Join Date: Mar 2001
Location: Rosanky, Texas
Posts: 68,125
Send a message via AIM to John Bridge
Oh, and on the subject of whether backer board adds structural value to the subfloor.

I've been involved in several discussions on this issue, with engineers and others, including "industry" people. Engineers seem to agree that if something is bonded to the floor, and that something has mass, it increses the stiffness of the floor. Gluing and screwing two sheets of plywood together, for example, makes a pretty stiff arrangement.

I can also understand why people don't want to bond CBUs to the floor as Art mentioned. But the hot/cold cycle in a house doesn't affect the plywood as much as it does the immediate substrate, be it mortar or backer board. I think that cracking in the past was more a result of wet plywood and substandard carpentry. We can argue that further.

Here's the deal, though. Comparing the rigidity of reinforced mortar to that of cement backer board is useless. The former is extremely rigid and does not fully depend on what's under it for its stiffness. The latter is only as good as what's under it -- if you subscribe to the school that says the backer adds nothing to the structure.

I'll tell you, folks, I can build a reinforced mud bed that can support itself with nothing under it. It'll never happen with backer boards unless they are vastly improved.
John Bridge 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


All times are GMT -6. The time now is 11:52 PM.


Sponsors

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2018 John Bridge & Associates, LLC