Installing Backerboard For Ceramic Tile Floor - Flooring - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Flooring


Thread Tools Display Modes
Old 09-24-2007, 08:42 AM   #1
Join Date: May 2007
Posts: 9
Rewards Points: 10

Installing Backerboard for Ceramic Tile Floor

I am just curious why it is necessary to tape and thinset the joints of backerboard as opposed to just butting the backerboard sections up against each other and moving on.


average is offline   Reply With Quote
Old 09-24-2007, 08:18 PM   #2
Join Date: Nov 2005
Location: Freeport, ME
Posts: 41
Rewards Points: 25

The main reason is because without the tape it cracks due to movement and those cracks will transmit up through your expensive floor. Actually the main reason to tape the seams is because the "manufacturer says so". They have years of testing data available and of course it was not cheap. This testing was not only by their labs but also done by independent labs. Another reason is if you don't follow their written instructions and if fails, they are under no obligation to warranty their products because it was not installed per their instructions. Another mistake is when all the edges of the sheets line up. Be sure and stagger them. The reasoning behind this is due to the fact that seams are the weakest points of the system. If you are installing on a floor, the 3' seams are not inline with the next row of 3' seams. This principle goes back to the American Plywood Assoc. for sheathing of walls and floors.


JJC is offline   Reply With Quote
Old 09-24-2007, 09:52 PM   #3
Custom Cabinet Maker
Join Date: Jun 2007
Location: Netcong NJ
Posts: 1,097
Rewards Points: 500

Also, by taping and thinset over, you create one contiguous water tight mass
skymaster is offline   Reply With Quote
Old 09-24-2007, 10:07 PM   #4
Join Date: May 2007
Posts: 9
Rewards Points: 10

thanks for the quick answers guys.

skymaster, i'm a little confused why it would make a difference if the backboard was a "water tight mass." it seems to me that if water is getting under the ceramic tile, then you're already in trouble. maybe i'm just missing the point altogether.
average is offline   Reply With Quote
Old 09-24-2007, 11:06 PM   #5
JazMan's Avatar
Join Date: Feb 2007
Location: Troy, Michigan
Posts: 5,860
Rewards Points: 422

It's not to make it a water tight mass, a floor with cement board is not going to hold water. The board its self may not be affected by water, but it's not water tight.

The purpose of tape is as mentioned before, to strengthen to joints and have a contiguous layer of concrete to bond tile on to.

You would not be in trouble when water gets under or behind your tiles. That's one of the reason we use CBU's in the first place. This of course as long as you don't use anything pre-mixed in a can.

JazMan is offline   Reply With Quote

Thread Tools
Display Modes

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
toilet install over new tile floor dbrew Plumbing 11 07-08-2014 08:34 AM
Tile over existing tile floor? dwalls32 Remodeling 3 07-03-2007 04:19 PM
bathroom floor tile job advice needed dbrew Flooring 14 01-23-2007 07:03 PM
Could installing a furnace to the floor joists cause the floor to slope? JKL HVAC 5 01-03-2007 09:23 PM
Kiwi tile for woodshop floor? rbh Flooring 2 08-20-2006 03:44 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1