to cut or not to cut? the suicide tile floor job

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JohnfrWhipple

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Roberto uncoupling membranes are ridiculous to begin with. In order for it to uncouple, the uncoupling membrane needs to de-bond. Who wants that?

Uncoupling membranes are not crack isolation membranes either. That's where the NobleSeal CIS and TS outperform the uncoupling membranes.

If these uncoupling membranes where as good as the makers of them say they are they would put them through the testing to get a crack isolation membrane approval. At Fontile here in Vancouver I have heard many times the counter sales people (and the sales floor staff) referring to "D" as a crack isolation membrane. But it's not. If it was it would be tested for this and have a crack isolation approval on it.

What a pickle RSCB is in trying to take care of his clients. All the rules from every Ya-Who out there. Codes. procedures. Blaa Blaa Blaa.

He needs to prep to floor so he feels the deflection is improved. He needs a flexible setting material. I think he is on the right track.
 

ShowerDude

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No pickle John,

I would never had touched this floor job if I didnt know exactly how to pre-measure deflection ratings, asess joist sytem or if I saw any crowning/settling etc.

This home is immaculate in its foundation/framing.

Heres A "Progress" photo to mull over! after all my 3/4 cleated ply is in ill block 16 oc and all seams from below. i will also plane the very minor differences in my joist tops before my top layer ply goes in.. Maybe a 1/16- 1/8 here and there .....

Me and my client can feel the drastic difference already. !

but yes its an extensive project for such a small area.

Im not going with strata mat. I am leaning towards TS now. Sometimes we make real world decisions on the fly with the avaiability of materials at hand.

ill have this prepped for tile by tuesday.........thx for the input

subfloor repair.jpg
 
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Eurob

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John ,

It doesn't mean that if Robinson test is passed , the membranes which did not pass do not work for an application . And you know this 'cause the uncoupling ones do work .

You want a crack isolation one .... no one said not to use it . No crack isolation membrane will increase the deflection rating .

Flexible mortars will be a plus , but I think RSCB knows that already .
 

ShowerDude

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John ,

Flexible mortars will be a plus , but I think RSCB knows that already .

Everyday Roberto I realize I know less and less, I realize 2 different routes sometimes can get to the same grocery store at the same time........ I dont know sh$# in the big scheme of things, but maybe a fair amount about the task at hand. Both you and John bring a valid skilled/experienced point and new angle to my projects ( as well as others Doug, Vegas HJ to name a few ).........
 

Eurob

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Everyday Roberto I realize I know less and less, I realize 2 different routes sometimes can get to the same grocery store. I dont know sh$# in the big scheme of things, but maybe a fair amount about the task at hand. Both you and John bring a valid point and new angle to my projects.........A trifecta if you will. THX

It is why we are constantly looking to improve our knowledge -- technical one -- ............... beside the hands on experience . I think what few angles of thinking can give you in the long run is speed in decisions of the path you want to take or not take , for a specific project or application .
 

Jadnashua

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Just screw your second layer to the first only, and it'll be as decoupled as any two-layer ply floor. Considering that the span of the first will be considerably shorter than between normal 16"oc with the cleats on the sides, it should be stronger than two layers just on top of the joists, especially since you'll have the full width of each cleat to glue your short ply sections to and their short span.
 

JohnfrWhipple

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With all the technical data. TCNA rules. TTMAC specifications it's nice to know that some rules are simple.

Like these two.

Whipple Rule #1

"If you can't hit it with a hammer. Kick it. Punch it. Then don't tile it"

Whipple Rule #2

"A glass of water filled to the brim (placed in the center of the room) should not spill when you walk around your job site. If it does the floor is bouncing too much."

Pretty basic rules in theory. No deflecto calculations. No manufactures recommended specs. The Hammer Rule is one that always comes into play for me.

Builder says the cement prep is solid. GREAT - Hit it with a hammer.

Not sure your scratch coat bonded well with the substrate. Hit it with a hammer.

Whipple Rule #3

"All framing should be able to hold your weight (i.e. ceiling framing and blocking)". You should be able to do chin ups on these framing members. If you can't - it's not good enough.

Whipple Rule #4

"When your shower bench is built. Kick it. Hard. Jump on it. It should be able to take a pounding. Now and later.... wink wink know what I mean?"
 

Jadnashua

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Roberto uncoupling membranes are ridiculous to begin with. In order for it to uncouple, the uncoupling membrane needs to de-bond. Who wants that?
One of the uncoupling membranes - SpiderWeb, actually does rely on some of the fibers shearing off to allow some uncoupling, but none of the others that I'm familiar with (Strata_Mat and Ditra) debond anything when they work...in neither of those two does thinset actually bond to the top of the membrane, so there is no bond to break! John doesn't understand. The open air grid structure of at least Strata_Mat and Ditra allow the tile/thinset assembly to move independently of the mat which is bonded to the substrate...thus, the uncoupling.

FWIW, the large amount of horizontal (shear) movement in any good uncoupling membrane provides a quite reliable crack isolation function as a secondary benefit. Keep in mind, though, that NO crack isolation or uncoupling membrane will work if there are VERTICAL differences between the two sides of any crack (implying vertical movement - uncoupling ONLY works for horizontal stresses).
 
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Jadnashua

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FWIW, if you put in that blocking every 16" or so, that ply on the cleats still isn't as strong as it would be if it was installed properly - grain is going the wrong way. The blocking, no matter how well it is installed, isn't as strong as the cleats on the joists. IOW, grain on any ply should run perpendicular with the joists.
 

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image.jpg
So as usual i went cross grain with my top 5/8" layer of bc exp 1 ply. I went ahead and glued it with titebond... To my cleated ply that is 3/4"...

LOL The oranje julious is back with an ice cream headache......!

Cross grain baby.......5/8"
 
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ShowerDude

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After i filled my cross grain ply and perimiter expansion gaps with silicone i went ahead and used a flex bond mortar and screws for my wonderboard .

The noble ts membrane was installed after i cleaned and moistened my wonderboard... And taped joints
 
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Jadnashua

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If you can't take the criticism, insults do not make something incorrect, correct. Anyone, ever, seen where installing ply parallel with the joists is a recommended install? Anyone ever hear where installing one layer in one direction, and the second perpendicular to it was right?

As an aside, an uncoupling membrane can provide crack isolation, but, a crack isolation membrane cannot provide uncoupling.
 

ShowerDude

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Basic common sense tells me 2 layers of plywood cross grain is the way to go ....... If the first layer weren't cleated and quasi uncoupled from the joists/second 5/8 id agree..... With said Common sense advice. Thx xoxo -counter

Show us some pics of your subfloor projects please....
 

Jadnashua

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Where would you rather have the 'strong' direction of the ply - spanning the continuous length of the joist on a cleat, or a short piece of blocking jammed and screwed across them. Now, with blocking installed every 16" as you indicated, it's probably fine in that way, but for even less work (time is money), you'd get a stronger result with just blocking the edges since you don't like T&G, and with the full width of the cleat to screw and glue to, what normally would be a span of 14.5" drops down to 11" with the ply spanning along its strong direction, rather than its weaker one.
 

ShowerDude

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Nice recital .


In reality i couldve used osb i could have used single layer 3/4 over the joist alone. Couldve. My deflection rating in joist/span alone is way above normal.....

I think were more than overbuilt. Thanks for letting us all know your opinion again.


I just noticed you are blocked by many people ?? Why is that?

Thanks for the jabs at my work...
 

DougB

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If you can't take the criticism, insults do not make something incorrect, correct. Anyone, ever, seen where installing ply parallel with the joists is a recommended install? Anyone ever hear where installing one layer in one direction, and the second perpendicular to it was right?

As an aside, an uncoupling membrane can provide crack isolation, but, a crack isolation membrane cannot provide uncoupling.

My god man! We aren't building an atomic sub - it's a freakin' foyer. IMO RSCB went to great lengths to ensure a quality job. Much more than most would do. Obviously there is a safety factor built into all these specs.

You're making yourself an obnoxious person.
 

JohnfrWhipple

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Nice work RSCB. !!!

I bet when you walk across the floor now it feels "Better".

Nice use of quality products. I see you used all my favourites.... Good on you.

What do you think of WonderBoard Lite?

Nice use of NobleSeal TS - that is a true crack isolation sheet - unlike the uncoupling membranes.
 

JohnfrWhipple

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RSCB - you have mention FlexBond before. How do you like it. I have only used it once I think and that was so long ago.

How does it compare to Laticrete 254?
 

Koa

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Nice recital .


In reality i couldve used osb i could have used single layer 3/4 over the joist alone. Couldve. My deflection rating in joist/span alone is way above normal.....

I think were more than overbuilt. Thanks for letting us all know your opinion again.


I just noticed you are blocked by many people ?? Why is that?

Thanks for the jabs at my work...

Many? Where on this site does one go to see how many people have a member blocked?
 
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