Hardibacker Thickness For Bathroom Floor - Flooring - DIY Chatroom Home Improvement Forum


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

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

Reply
 
Thread Tools Display Modes
Old 11-15-2011, 07:52 PM   #1
Member
 
Join Date: Apr 2007
Posts: 2,302
Rewards Points: 1,038
Question

Hardibacker thickness for bathroom floor


should i use 1/4 or 1/2" Hardibacker for my bathroom floor? the beams underneath are 2x10 and the subfloor is 3/4" tongue-and-groove OSB. i plan to use 12x12, 3/8" thick marble tiles.

thanks

Advertisement

amakarevic is offline   Reply With Quote
Old 11-15-2011, 09:55 PM   #2
DIY staff

 
Join Date: Sep 2009
Location: Kane county,Illinois
Posts: 22,271
Rewards Points: 3,182
Default

Hardibacker thickness for bathroom floor


Marble will need a very stiff floor---the 3/4" osb is not stiff enough--adding 1/2" BC plywood will be needed---then 1/4" cement board set in thinset and nailed or screwed.

These 2x10 floor joists---what is the unsupported length?--( from foundation to beam or from outside wall to bearing wall if it's a second floor)

Advertisement

__________________
New members: Adding your location to your profile helps in many ways.--M--
oh'mike is online now   Reply With Quote
The Following User Says Thank You to oh'mike For This Useful Post:
amakarevic (11-16-2011)
Old 11-15-2011, 10:23 PM   #3
Tileguy
 
JazMan's Avatar
 
Join Date: Feb 2007
Location: Troy, Michigan
Posts: 4,183
Rewards Points: 2,224
Default

Hardibacker thickness for bathroom floor


Mike is absolutely right, you need more strength between the joists. Probably won't meet minimums for joists' deflection either. Let us know what the span is along with species and grade if you can find that info stamped on the joists.

Jaz
__________________
Tile 4 You LLC Troy, MI

DITRA Installs - KERDI Watertight-Mold-Free Showers. I have NEVER made a mistake, I thought I did ONCE, but, I was WRONG! A+ BBB rating - est. 1987 - over 50 yrs. exp.
JazMan is offline   Reply With Quote
The Following User Says Thank You to JazMan For This Useful Post:
amakarevic (11-16-2011)
Old 11-16-2011, 12:19 AM   #4
Member
 
Join Date: Apr 2007
Posts: 2,302
Rewards Points: 1,038
Question

Hardibacker thickness for bathroom floor


i doubt the beams will be sagging because they are only 12 ft long and there are two load bearing walls on the floor under perpendicular to them (powder room - load bearing wall - hallway - load bearing wall - utility alcove).

having said that do you think the existing 3/4 OSB + maybe 1/2" DUROCK maybe will do? i heard durock is stronger than hardibecker (although i like hardibecker cause it seems easier to cut).

besides, if i did what you suggested, it would be so much higher than outside the bathroom (carpet on top of subfloor) that it would look awkward, kind of like half a step up almost ... LOL

Last edited by amakarevic; 11-16-2011 at 12:26 AM.
amakarevic is offline   Reply With Quote
Old 11-16-2011, 05:40 AM   #5
DIY staff

 
Join Date: Sep 2009
Location: Kane county,Illinois
Posts: 22,271
Rewards Points: 3,182
Default

Hardibacker thickness for bathroom floor


Backer board adds no strength what so ever--so 1/4" is plenty.
OSB is weak and flexible--add plywood on top or live with cracked stone.

If your joists are 2x12 and the spacing is 16"---and the span is 12 feet---it's a chancy install for stone.

Your deflection is 558-----stone requires 720 and tile 360----good floor but not great,
__________________
New members: Adding your location to your profile helps in many ways.--M--
oh'mike is online now   Reply With Quote
The Following User Says Thank You to oh'mike For This Useful Post:
amakarevic (11-16-2011)
Old 11-16-2011, 02:19 PM   #6
Member
 
Join Date: Apr 2007
Posts: 2,302
Rewards Points: 1,038
Default

Hardibacker thickness for bathroom floor


so for the 1/2" additional subfloor support on top of the normal 3/4" OSB subfloor, should i use OSB or plywood?

also, since it will be a big jump up when you get in the bathroom, what do you recommend for the threshhold divider, considering it is marble tile inside?

thanks
amakarevic is offline   Reply With Quote
Old 11-16-2011, 02:21 PM   #7
Tileguy
 
Bud Cline's Avatar
 
Join Date: Mar 2006
Posts: 10,464
Rewards Points: 2,576
Default

Hardibacker thickness for bathroom floor


Use "underlayment grade" plywood (Exposure 1).
Bud Cline is offline   Reply With Quote
The Following User Says Thank You to Bud Cline For This Useful Post:
amakarevic (11-16-2011)
Old 11-16-2011, 02:33 PM   #8
Member
 
Join Date: Apr 2007
Posts: 2,302
Rewards Points: 1,038
Question

Hardibacker thickness for bathroom floor


thanks, Bud. one more question: for the walls, does that require 1/2" cement board?
amakarevic is offline   Reply With Quote
Old 11-16-2011, 02:36 PM   #9
Tileguy
 
Bud Cline's Avatar
 
Join Date: Mar 2006
Posts: 10,464
Rewards Points: 2,576
Default

Hardibacker thickness for bathroom floor


Quote:
for the walls, does that require 1/2" cement board?
Always 1/2" on wall studs, never anything less.
Bud Cline is offline   Reply With Quote
The Following User Says Thank You to Bud Cline For This Useful Post:
amakarevic (11-16-2011)
Old 11-16-2011, 03:44 PM   #10
Member
 
Join Date: Apr 2007
Posts: 2,302
Rewards Points: 1,038
Default

Hardibacker thickness for bathroom floor


what is everyone's favorite cement board brand? hardibacker or durock?
amakarevic is offline   Reply With Quote
Old 11-16-2011, 06:22 PM   #11
DIY staff

 
Join Date: Sep 2009
Location: Kane county,Illinois
Posts: 22,271
Rewards Points: 3,182
Default

Hardibacker thickness for bathroom floor


They are both a fine product---I prefer Durrock or Wonder board --but only because that is what I learned many years ago and have never had a failure--

Many installers use mostly Hardi---personal choice--
__________________
New members: Adding your location to your profile helps in many ways.--M--
oh'mike is online now   Reply With Quote
Old 11-18-2011, 04:00 PM   #12
Member
 
Join Date: Apr 2007
Posts: 2,302
Rewards Points: 1,038
Default

Hardibacker thickness for bathroom floor


Quote:
Originally Posted by Bud Cline View Post
Use "underlayment grade" plywood (Exposure 1).
is this a good kind?

thanks
Attached Thumbnails
Hardibacker thickness for bathroom floor-under_tile_plywood_x.jpg  
amakarevic is offline   Reply With Quote
Old 11-18-2011, 04:29 PM   #13
Tileguy
 
JazMan's Avatar
 
Join Date: Feb 2007
Location: Troy, Michigan
Posts: 4,183
Rewards Points: 2,224
Default

Hardibacker thickness for bathroom floor


No, that is sheathing not underlayment. Go down the aisle a little further and you will find it.
http://www.lowes.com/pd_12227-99999-...7C1&facetInfo=

Jaz
__________________
Tile 4 You LLC Troy, MI

DITRA Installs - KERDI Watertight-Mold-Free Showers. I have NEVER made a mistake, I thought I did ONCE, but, I was WRONG! A+ BBB rating - est. 1987 - over 50 yrs. exp.
JazMan is offline   Reply With Quote
The Following User Says Thank You to JazMan For This Useful Post:
amakarevic (11-18-2011)
Old 11-18-2011, 08:43 PM   #14
Tileguy
 
Bud Cline's Avatar
 
Join Date: Mar 2006
Posts: 10,464
Rewards Points: 2,576
Default

Hardibacker thickness for bathroom floor


What you are looking for should be labeled "underlayment". It will also be "exterior grade". It will also be called "Exposure 1". It will also likely be "B-C". Unfortunately nomenclature varies around the country but "sheathing" definitely is not what you want.
Bud Cline is offline   Reply With Quote
Old 11-19-2011, 06:25 AM   #15
DIY staff

 
Join Date: Sep 2009
Location: Kane county,Illinois
Posts: 22,271
Rewards Points: 3,182
Default

Hardibacker thickness for bathroom floor


If plywood were clothing----

Sheathing is like a shirt---it's worn on the sides of a house---to be covered by siding---

Underlayment is like shoes----tough and strong and won't fall apart if you step in a puddle.

For tile---look for BC exposure 1-

The letters mean the quality of the faces--

A-smooth sanded-no voids

b-smooth voids are filled

c-rough small voids allowed

d-nasty--open knots and large voids are allowed

Advertisement

__________________
New members: Adding your location to your profile helps in many ways.--M--
oh'mike is online now   Reply With Quote
Reply


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
Creating a flat floor on an angled concrete floor? Magno Building & Construction 1 04-14-2011 06:42 AM
Tile over existing floor tile radient with electric heat brownieruf Off Topic 7 05-22-2010 07:49 PM
2nd floor air flow/pressure fgillis HVAC 7 02-24-2009 05:58 AM
Levelling wood floor gomi_otaku Building & Construction 13 11-27-2008 08:45 AM
Old old linoleum, can it take paint? molamola Painting 23 11-11-2008 07:32 PM




Top of Page | View New Posts