Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Welcome to John Bridge / Tile Your World, the friendliest DIY Forum on the Internet


Advertiser Directory
JohnBridge.com Home
Buy John Bridge's Books

Go Back   Ceramic Tile Advice Forums - John Bridge Ceramic Tile > Tile & Stone Forums > Tile Forum/Advice Board

Sponsors


Reply
 
Thread Tools Search this Thread
Old 09-01-2003, 06:35 AM   #1
Sam
Registered User
 
Join Date: Sep 2003
Location: Maryland
Posts: 14
CPE membrane over plywood?

In our bathroom renovation, I'd like to waterproof the floor since our kids will be using the tub. Can I put CPE membrane directly over the plywood subfloor, then tile on top of the membrane?

The subfloor seems solid: it's 1-1/4" thick, made from 3/4" exterior plywood screwed through 1/2" plywood into the joists below using 3" screws. The joists are 16" apart but the original builder put in a couple extra joists - one where the bathroom floor meets the wall, and another running down the middle of the bathroom floor.

Or should I put 1/4" Wonderboard over the plywood subfloor, then CPE, then tile? We have 12"x12" porcelain tile and SuperFlex thinset for use between all layers.

Thanks.
Sam is offline   Reply With Quote
Sponsored Links
Old 09-01-2003, 06:49 AM   #2
Jason_Butler
Tile Setter
 
Join Date: May 2001
Location: Austin, TX
Posts: 4,840
Are we talking about the bathroom floor ( as opposed to the shower floor) ?

If it's the bathroom floor you want to waterproof, I would add the CBU atop the existing plywood and use a roll on waterproofer over the CBU.

You can tile directly over the roll-on waterproofer.

Jason
__________________
Good..Fast..Cheap. Pick any 2...can't have all three
Jason_Butler is offline   Reply With Quote
Old 09-01-2003, 07:22 AM   #3
tileguytodd
Official Felker Fanatic
 
tileguytodd's Avatar
 
Join Date: Jun 2002
Location: Northern MN
Posts: 14,398
2 of the easier Trowelable/paintable membranes are
C-Cure Pro Red 963 and
Custum Redgaurd
__________________
TIP YOUR TILE MAN, His Retirement plan is not nearly as lucrative as yours and his waning years will be far more painful to boot.
He gives much so you can have a Beautiful Home!!
tileguytodd is offline   Reply With Quote
Old 09-01-2003, 09:59 AM   #4
Sam
Registered User
 
Join Date: Sep 2003
Location: Maryland
Posts: 14
Thanks for the suggestions. Right now the toilet flange is set at 5/8" above the level of the plywood subfloor. With 1/4" CBU and 3/8" tile plus thinset and waterproofing, the toilet flange will end up below the level of the finished tile. Is there a product to raise the toilet flange up to the level of the finished tile or above?
Sam is offline   Reply With Quote
Old 09-01-2003, 10:03 AM   #5
Jason_Butler
Tile Setter
 
Join Date: May 2001
Location: Austin, TX
Posts: 4,840
I've seen a few products that "extend"the flange to be flush with the finished floor.

You can also use the Jumbo wax ring or double up the standard rings. You will probably need the longer toilets bolts if you use compensate with the wax rings.

Jason
__________________
Good..Fast..Cheap. Pick any 2...can't have all three
Jason_Butler is offline   Reply With Quote
Old 09-01-2003, 05:42 PM   #6
John Bridge
Mudmeister
 
Join Date: Mar 2001
Location: Houston, Texas
Posts: 66,933
Send a message via AIM to John Bridge
Hi Sam, Welcome.

An alternative is to apply Schluter "Ditra" to the plywood and tile to that. Ditra is only an eighth of an inch thick. It is also a waterproofer.

http://www.schluter.com
John Bridge is offline   Reply With Quote
Old 09-01-2003, 07:08 PM   #7
Rob Z
Guest
 
Posts: n/a
Sam

Noble TS is a waterproof CPE sheet membrane that can have tile bonded to it. It is about 1/16th thick and is bonded to the substrate with modified thinset. www.noblecompany.com.


Is top of the flange 5/8th off the floor? If so, then it set correctly.
  Reply With Quote
Old 09-02-2003, 05:29 AM   #8
Sam
Registered User
 
Join Date: Sep 2003
Location: Maryland
Posts: 14
Thanks. Ditra sounds like a good alternative - it's thinner than the Wonderboard & CPE membrane we were going to use.

We were going to cut the Wonderboard and CPE to allow a 1/4" expansion joint next to the walls, tub, pipes, and flange. If we use Ditra, is a 1/4" expansion joint also recommended?

The top of the toilet flange is 5/8" above the plywood.
Sam is offline   Reply With Quote
Old 09-02-2003, 06:40 AM   #9
tileguytodd
Official Felker Fanatic
 
tileguytodd's Avatar
 
Join Date: Jun 2002
Location: Northern MN
Posts: 14,398
The 1/4" expansion filled with caulk is the way to go.Dont worry about the toilet flange,it really is a non issue based on your figures.Using the ditra you probobly wont even need a second wax ring.
__________________
TIP YOUR TILE MAN, His Retirement plan is not nearly as lucrative as yours and his waning years will be far more painful to boot.
He gives much so you can have a Beautiful Home!!
tileguytodd is offline   Reply With Quote
Old 09-02-2003, 10:54 AM   #10
John Bridge
Mudmeister
 
Join Date: Mar 2001
Location: Houston, Texas
Posts: 66,933
Send a message via AIM to John Bridge
Nobleseal is also Dalseal -- sold at Daltile stores.

1/4 for expansion is fine, but if it's going to be visible I would cut it down to an eighth.
John Bridge is offline   Reply With Quote
Old 09-03-2003, 02:22 AM   #11
Sam
Registered User
 
Join Date: Sep 2003
Location: Maryland
Posts: 14
Thanks everyone. We were going to use CPE only because we had previously bought a sheet of it. But we'll use Ditra instead. I'm glad I found out about this forum "just in time", before we put anything down on the floor.
Sam is offline   Reply With Quote
Old 09-03-2003, 06:04 PM   #12
John Bridge
Mudmeister
 
Join Date: Mar 2001
Location: Houston, Texas
Posts: 66,933
Send a message via AIM to John Bridge
Sam,

The problem with shower pan membrane is that nothing want's to stick to it. The other membranes we've mentioned love thin set.
John Bridge is offline   Reply With Quote
Reply

Stonetooling.com   Tile-Assn.com   National Gypsum Permabase


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Forum Jump


All times are GMT -6. The time now is 02:44 AM.


Sponsors

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2014 John Bridge & Associates, LLC