# Rule of Thumb for Trowel size and Spacer size please..



## R&D Tile (Feb 6, 2006)

First, why are you using that thinset, is the Ditra going over plywood, I wouldn't use that thinset to set the tile, it's highly modified, Ditra calls for unmodified.

As for spacing and trowel size, all depends on the type of tile, if just regular porcelain with a beveled edge, not rectified or square edged, a 1/4x3/8" square notch will be fine and a 3/16" grout joint will look nice and sanded grout.

Backbutter each tile with the flat side of the trowel as you set them, notched side on the floor after you fill the Ditra squares.


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## JazMan (Feb 17, 2007)

Please clarify what the substrate is and how you planned to use Kerabond & Keralastic. 

To install Ditra, Schluter has tweaked their recommendations a bit. They now make a Ditra trowel which is 11/64 square notch. Pretty close to 3/16". they also said a 3/16x1/4 V or 5/16" V. I think their original 3/16 x 1/4" V was too small, and I used to cut them bigger. So, 3/16 square or 5/16 V I say.

I agree with the 1/4x3/8x1/4 square to install standard 13". Shouldn't have to back butter if mixed & applied right, but won't hurt of course. I don't use spacers on floors, but I try to go about 3/16" unless it's a cheap tile which is likely to be off-size. 

Get back with details on the subfloor, we may have you jump through a few hoops first.

Jaz


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## K.M.G (Aug 30, 2009)

KeraBond is a Premium Dry-set morter,the keralastic jug Makes it Modified 

Not just adding plan water like how I plan to set the tiles.

I've done my research on the Kerabond/Keralastic,but thanks for your help

I've also changed my plan now as I won't spend $61.00 for a Jug of Keralastic.

So I'm using Ultraflex II-III for Setting the Ditra Now,and my White bag of Kerabond for setting the tiles.

The Subfloor is Plywood

The Tiles are Unicom Starker Porcelain 13x13 Square tiles 

I guess it's beveled edge on each side

If I pick to small of a Grout line would I crack the grout 

I bought some 3/16 spacers for a $1.00 and put two together and the line looks to big for my taste but I don't have finally say:thumbup:

The area is only 30 s.q F.t

I thought a smaller line would make the floor look like one big tile,as they are a Cream/white tile.




R&D Tile said:


> First, why are you using that thinset, is the Ditra going over plywood, I wouldn't use that thinset to set the tile, it's highly modified, Ditra calls for unmodified.
> 
> As for spacing and trowel size, all depends on the type of tile, if just regular porcelain with a beveled edge, not rectified or square edged, a 1/4x3/8" square notch will be fine and a 3/16" grout joint will look nice and sanded grout.
> 
> Backbutter each tile with the flat side of the trowel as you set them, notched side on the floor after you fill the Ditra squares.


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## K.M.G (Aug 30, 2009)

JazMan said:


> Please clarify what the substrate is and how you planned to use Kerabond & Keralastic.
> 
> To install Ditra, Schluter has tweaked their recommendations a bit. They now make a Ditra trowel which is 11/64 square notch. Pretty close to 3/16". they also said a 3/16x1/4 V or 5/16" V. I think their original 3/16 x 1/4" V was too small, and I used to cut them bigger. So, 3/16 square or 5/16 V I say.
> 
> ...



Wow

Thanks

Should I spend the $18 and buy the Ditra 11/64x11/64 Trowlel,or should I get a $5.00 3/16 or 5/16 trowel like you mentioned.

If you say you don't need the Ditra 11/64 Trowel out of the 3/16 or 5/16 whats the best to use for Ditra on on plywood.

Are those 3/16 or 5/16 to whole notches to the trowel or Different sizes mixed in.

So I know what to look for and not stand there for 10 mins confused like I usually do in that area.:001_unsure:

Thanks again

K.G


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## R&D Tile (Feb 6, 2006)

Jaz, it's a good idea to always backbutter Porcelain.

Size of the joint is up to you, you can go as tight as you wish, just use unsanded grout if less than 1/8", no, it won't crack.

If the tile isn't sized great, that would be the only problem keeping a tight joint, but seeing it's a small area, shouldn't be a concern.


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## K.M.G (Aug 30, 2009)

R&D Tile said:


> Jaz, it's a good idea to always backbutter Porcelain.
> 
> Size of the joint is up to you, you can go as tight as you wish, just use unsanded grout if less than 1/8", no, it won't crack.
> 
> If the tile isn't sized great, that would be the only problem keeping a tight joint, but seeing it's a small area, shouldn't be a concern.


Well thank you for all your help so far

Getting very close to starting the tile job,just need to finish painting the room 

Do I need to put thinset on the Ditra first and then on the back of the tile

I'm a little confused on the Back butting the tiles

I'm thinking this is how it goes,spread the thin-set and then do your notches,put thinset on the tile and put your notches on it.

Then set the Tile into place with a firm twist and check for level???

*Mr R&D Tile*

Can you elaborate on the Trowel size please too seeing as your a tile Pro,I read your reply on setting the Tile with a 1/4-3/8 trowel, Great.

But didn't see any recommends for the Ditra and Jazman hasn't gone back

I will post a picture of the Tile front&back


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## JazMan (Feb 17, 2007)

KMG,

You spread thin set on the floor and get a good mechanical bond using the flat side of the trowel. Since you're using Ditra, be sure the dove tails get filled, then spread more thin set and gauge it with the notched trowel. It's best to have the ridges going in one direction, east-west. If you're buttering the tiles too, simply spread a film of thin set with the flat side of the trowel. Now set the tile and slide it forward & backwards to get a good bond and collapse the ridges. This method give you the best adhesive transfer. You do not apply more than a film on the tiles if any at all. 

R&D didn't elaborate on Ditra because I had already done that. What aren't you sure about?

Jaz


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