# Mortar Board???



## primetimeon (Mar 16, 2009)

Help me out here, I have a client that insists on using mortar board?? over a concrete slab floor.I thought she meant mortar bed but she insists it is board. Two other tile contractors supposedly said the same thing. 
Are they saying to use durarock over the slab?? and if so why? The slab is in great shape just a couple low spots that can easily be self leveled.

am I losing it or do you put durarock (mortar board) over the slab? Also how many of you still lay a mortar bed over a good concrete slab?


----------



## primetimeon (Mar 16, 2009)

I have been using the ditra over the slabs and have not done a mortar bed in a long time. so just wondering how many of you still use a mortar bed over a slab instead of ditra or similar product?


----------



## TileLady (Apr 8, 2008)

I think the customer is confused. There's no reason to put cement board over cement. Sounds like the other 'contractors' she spoke to dont know what they're talking about either. :no:


----------



## jarvis design (May 6, 2008)

Putting concrete board over a concrete slab us completely useless!! What are these guys gonna do, drill and screw with tapcons?? Lol

Ditea is a great idea!!


----------



## Evan1968 (Dec 5, 2010)

Primetimeon said:


> do you put durarock (mortar board) over the slab?


 Your not serious with that question are you?


Go for it and cover all the bases....Durarock(mortared and tapcon of course!) then Ditra and in between use some anti-fracture membrane. That makes a great sandwich!:thumbsup::thumbsup:

She has been told she needs a _mortar bed_ and she heard_ mortar board._

The other question is why is it needed in the first place?

Why havent you pulled out your TCA or ANSI handbook and showed her its _mortar bed _and that the other contractors are wrong?

The only reason i see to use Ditra on a SOG would be to build up for height issues or for a crack suppression membrane.


----------



## Bill_Vincent (Apr 6, 2005)

I dunno-- the onliest mortar board I ever hear tell of is the one at the bottom of this pick, with the mud on it!


----------



## HS345 (Jan 20, 2008)

Evan1968 said:


> The only reason i see to use Ditra on a SOG would be to build up for height issues or for a crack suppression membrane.


Except that Ditra does not bill itself as, nor is it a crack suppression membrane.


----------



## Evan1968 (Dec 5, 2010)

Ditra Website said:


> *a) Uncoupling
> Tile has been successfully installed for thousands of years by incorporating an uncoupling layer, or forgiving shear interface, within the tile assembly. Schluter-DITRA provides uncoupling through its open rib structure, which allows for in-plane movement that effectively neutralizes the differential movement stresses between the substrate and the tile, thus eliminating the major cause of cracking and delaminating of the tiled surface.*



....close enough.....


----------



## HS345 (Jan 20, 2008)

Evan1968 said:


> ....close enough.....


If you say so. :whistling


----------



## Evan1968 (Dec 5, 2010)

I do...and so does this guy ( http://www.ontariotile.com/ditra.html )....its a matter of semantics i guess. Just because it doesnt specifically say that exact use, it doesnt mean it cant be used a certain way.


----------



## HS345 (Jan 20, 2008)

Evan1968 said:


> I do...and so does this guy ( http://www.ontariotile.com/ditra.html )....its a matter of semantics i guess. Just because it doesnt specifically say that exact use, it doesnt mean it cant be used a certain way.


It's not semantics, it's mechanics. If Ditra were a suitable crack suppression membrane, wouldn't Schluter say so? Wouldn't they take advantage of that?

Does Harry Dunbar work for Schluter? No, he doesn't. 

Don't get me wrong, Harry is a fine craftsman, I am not in any way trying to diminish that. But he is wrong about Ditra being a crack iso membrane.


----------



## Evan1968 (Dec 5, 2010)

How about this....do you think Ditra can help suppress cracks transferring up through the tile when installed properly? 

Agree 100% that Ditra does not come right out and say or endorse itself as a crack isolation membrane. They come close though. 

Lots of products can have secondary uses not stated or endorsed by the manufacture. Dont mean they dont work as such. Just sayin....


----------



## HS345 (Jan 20, 2008)

Evan1968 said:


> How about this....do you think Ditra can help suppress cracks transferring up through the tile when installed properly?


No, I do not. Yes, Ditra can help prevent cracks in tile from movement, and other stresses. But it cannot help prevent existing cracks from transmitting up through the tile. Don't believe me? Ask Schluter.


----------



## Evan1968 (Dec 5, 2010)

I believe you.... but isnt movement of the substrate how we get cracks in the first place? :confused1::cheesygri


----------



## HS345 (Jan 20, 2008)

Evan1968 said:


> I believe you.... but isnt movement of the substrate how we get cracks in the first place? :confused1::cheesygri


Aren't we talking about existing, and future cracks in concrete? What does that have to do with movement in a wood substrate?


----------



## primetimeon (Mar 16, 2009)

Ok, thanks for all the comments guys.

Talked to the H.O and she swears it is mortar board but I showed her alot of material on this matter and has agreed with the ditra over the slab. 

I have a few areas in my house that have tile and laid with different methods, 1. mortar bed laid 7 years ago 2. ditra laid 2 years ago and 3. over hardiboard laid 3 years ago.

I live in california and have had some good shakers in the past 5 years and so mar the i have minor grout cracking in the mortar bed, one tile cracked in half on the hardi and nothing on the ditra.

Is it just the area in the house? is it the way it was layed? Don't know but it is enough proof for me to be comfortable using it and to suggest it to all my customers.


----------

