[porchhen9]

I am new to this forum so bare with me a little. I am currently redoing my bath/shower
( alcove tub) area. I have installed 6 mil poly over studs and am having my drywall
contractor install cement board for me. my question is two fold 1. what kind of finishing
should there be on the cement board seams and what kind of thinset should I use for
3 x 5 inch porcelain tile. 3 product selections would be good so I could pick from those.
Thanks

 

[Bud Cline]

Any modified thinset mortar will work just fine. If you have access to a Home Depot they sell Versabond. Versabond is as good as anything for this application.

Use the alkali-resistant mesh tape for the seams. Apply the tape and then press the thinset into the joints through the tape just ahead of installing the tile all in the same time frame.

 

[Mark Harvey]

Tiles

As to the cement board, don't worry about the seams as they will be covered by the tiles. The thinset will fill in the gap as well. As to the type, there are many good ones. Talk to your local supplier or tile store about recommended brand. Ask about easy of use (assuming this is a new project) and proper trowel to use. The groove spacing makes a difference so, again, ask the tile people. Good luck and welcome to the site.

 

[Bud Cline]

As to the cement board, don't worry about the seams as they will be covered by the tiles.

Not exactly sure what that statement is supposed to mean but you certainly wouldn't want to ignore the seams and simply install the tile over them without addressing the seams with joint tape.

AGAIN...Use the alkali-resistant mesh tape for the seams. Apply the tape and then press the thinset into the joints through the tape just ahead of installing the tile all in the same time frame.

 

[Mark Harvey]

Cement board

Hi Bud, not to be disrespectful, but people I've worked with don't add the tape to the seams. Why do you recommend this? I understand taping for drywall but when there is a hard finish, like tile, aren't the seams covered?

I may be misinformed and stand to be corrected. I appreciate your feed back.

 

[Bud Cline]

Hi Bud, not to be disrespectful, but people I've worked with don't add the tape to the seams. Why do you recommend this? I understand taping for drywall but when there is a hard finish, like tile, aren't the seams covered?

I may be misinformed and stand to be corrected. I appreciate your feed back.

WHY?
Well because it is in all of the industry How To Books. It is the standard. It is the way of The Tile Council of North America. It is the way of The National Standards Institute of America, it is the way of The Marble Institute of America, it is the way of the National Tile Contractors Association, it is taught by The Ceramic Tile Educational Foundation. It is the installation directions of all of the cement board manufacturers.

The tape and thinset over ALL seams is to maintain the integrity of the board-plane. With tape the individual units become unitized and basically become one. Without tape the boards remain individual boards and tile is subject to cracking.

people I've worked with don't add the tape to the seams.

I don't know what to say about that. Can they read?