Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Remodeling > Kitchen & Bath Remodeling

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-24-2009, 01:26 PM   #1
Member
 
Join Date: Jul 2008
Posts: 31
Rewards Points: 25
Default

Cementboard and Silicone?


I recently installed hardibacker board in a walk in shower. Leaving 1/8" gap between, then filled with waterproof silicone. I plan to use mesh and thinset over the seems also. Is this overkill and is this a good process? Thanks

rolls831 is offline   Reply With Quote
Old 01-24-2009, 02:30 PM   #2
K&B Remodeler/Tile Guy
 
angus242's Avatar
 
Join Date: Apr 2008
Location: Illinois
Posts: 887
Rewards Points: 500
Default

Cementboard and Silicone?


Quote:
Originally Posted by rolls831 View Post
Leaving 1/8" gap between, then filled with waterproof silicone.
Gap where?

__________________
Angus
My Albums
angus242 is offline   Reply With Quote
Old 01-24-2009, 07:28 PM   #3
Member
 
Join Date: Jul 2008
Posts: 31
Rewards Points: 25
Default

Cementboard and Silicone?


Hi Angus242. Thanks for the reply. The gaps are between the sheets of backerboard where they meet, also where the board meets the shower pan. This is a full walk in shower 33x60.
rolls831 is offline   Reply With Quote
Old 01-24-2009, 10:50 PM   #4
Member
 
Tom Struble's Avatar
 
Join Date: Dec 2008
Location: west milford n.j.
Posts: 2,785
Rewards Points: 2,000
Default

Cementboard and Silicone?


silicone is not the best sealant for porous materials better off with a urethane
Tom Struble is offline   Reply With Quote
Old 01-24-2009, 11:23 PM   #5
Registered User
 
Termite's Avatar
 
Join Date: Apr 2008
Posts: 6,520
Rewards Points: 2,000
Default

Cementboard and Silicone?


If it isn't too late I'd remove the silicone and properly fill/pack the joint with thinset and of course mesh tape the seam. Honestly, there should not be a gap at all.
Termite is offline   Reply With Quote
Old 01-25-2009, 12:10 AM   #6
K&B Remodeler/Tile Guy
 
angus242's Avatar
 
Join Date: Apr 2008
Location: Illinois
Posts: 887
Rewards Points: 500
Default

Cementboard and Silicone?


The even plane seams should be addressed with alkali-resistant tape and thinset, no gaps. The gap between the tile and shower pan will be caulked.
You should waterproof before tiling.
__________________
Angus
My Albums
angus242 is offline   Reply With Quote
Old 01-25-2009, 02:15 PM   #7
Member
 
Join Date: Jul 2008
Posts: 31
Rewards Points: 25
Default

Cementboard and Silicone?


I'm including a photo. The gaps are 1/8" as you can see they are filled with 100% silicone. I will apply mesh then thinset. after drying and smoothing, I plan to coat with RedGuard. I really don"t want to remove the silicone unless an expert says this will lead to a disaster.
Attached Thumbnails
Cementboard and Silicone?-100_0133.jpg  
rolls831 is offline   Reply With Quote
Old 01-25-2009, 04:25 PM   #8
K&B Remodeler/Tile Guy
 
angus242's Avatar
 
Join Date: Apr 2008
Location: Illinois
Posts: 887
Rewards Points: 500
Default

Cementboard and Silicone?


I don't understand why you chose to leave gaps filled with silicone.

ANSI standard A108.11 states to use alkali-resistant tape over the seams and then fill with thinset. This would be true for all seams except to the floor, shower pan or tub deck.

Hardibacker installation instructions say to follow ANSI A108.11. It also states to tape and fill seams as above.

TCNA method W244C-07 also says to tape and fill with thinset.

None of the above methods say to have vertical gaps.

Furthermore, thinset will not adhere to silicone.

You've decided to use your own installation method. I don't see disastrous results but you've strayed from tested building procedures. The "overkill" isn't taping and using thinset on the seams, it was the use of silicone in all gaps.

__________________
Angus
My Albums
angus242 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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





Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.