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
Unread 10-30-2009, 01:06 PM   #1
s71ce
Registered User
 
Join Date: Oct 2009
Posts: 2
Laundry Room Floor

Gentlemen
I need some advice on a Laundry Room floor installation. The details are:
- Room size is 12' X 10'; 2x10's at 16" o/c floor framing; span of joists is broken by a girder beneath so max span of floor joists is about 7'
- Original vinyl floor covering- have removed vinyl and underlayment
- Original subfloor is 1/2" plywood- it is in good condition, however, I don't think it is solid enough for washer/ dryer. The floor has a sag in it of about 7/16"max, and it is about at midspan (yes, even with the girder beneath)

I am planning to install 3/4" plywood on cleats between the joists beneath the subfloor to beef up to 1 1/4". Then install 1/4" Hardibacker over the existing subfloor, then install 16" tiles on that. I would like some feedback on my plans and if they are a good approach, and some advice on how to make sure the floor is level...i.e. should I install as outlined and then float a self leveling compound on top of the Hardibacker prior to the tile? or can I level the floor with thinset on top of the hardibacker (by screeding) and then install tile. I would appreciate any other advice . Thanks
__________________
Mike
s71ce is offline   Reply With Quote
Sponsored Links
Unread 10-30-2009, 01:23 PM   #2
cx
Moderator emeritus
 
cx's Avatar
 
Join Date: Jul 2001
Location: Boerne, Texas
Posts: 96,051
Welcome, Mike.

You need to know the unsupported span of your floor joists on either side of the support in the center of your room. The longest unsupponted span of any joist supporting any part of your tile installation is what you're looking for.

It is possible to support your subflooring in the manner you propose so long as it's well executed with the face grain of the plywood reinforcement perpendicular to the joists and the upper layer firmly attached to the new stiffeners. You might wanna weigh the difficulty with that of simply removing the existing subflooring and starting over with 3/4" plywood.

I'd wanna know the reason for the "sag" in the joists and correct that if possible. Would be easier to do while the subflooring is removed, 'specially if you find that your joists need some help anyway.

Keep in mind that your floor doesn't give a rat's patooti about level, it cares only about flat. And with those large format tiles, you'll want more flat than called for by industry standards.

Thinset mortar is not meant to be used for flattening nor leveling of the substrate, but can be used for minor deficiencies. Your overall deficiency does not appear to be minor.

My opinion; worth price charged.
__________________
CX

Y'ALL NEW VISITORS READ THIS HERE!
cx is offline   Reply With Quote
Unread 10-30-2009, 05:44 PM   #3
s71ce
Registered User
 
Join Date: Oct 2009
Posts: 2
Laundry room floor

Thanks for the reply. I am new to this forum and really appreciate thef knowledge and insight. I plan to get underneath the floor tomorrow to see if I can determine the cause of the sag. If I elect not to remove the subfloor and apply 3/4" ply under the existing subfloor, how would you suggest I flatten the floor. Flatten and level on top of the hardiboard? What would work best? What is the easiest? Thanks
__________________
Mike
s71ce is offline   Reply With Quote
Unread 10-30-2009, 05:50 PM   #4
Davestone
Florida Tile & Stone Man
 
Join Date: Apr 2004
Location: Naples Fl.
Posts: 22,690
Mike as said, you need to find out why it's sagging, could be someone cut notches in the joists or termites are there.
__________________
Dave



http://Davestonestile.com
Davestone is offline   Reply With Quote
Unread 10-31-2009, 07:25 AM   #5
bbcamp
Registered User
 
Join Date: Jul 2002
Posts: 30,274
Flatten on top of the hardiboard using thinset or medium set mortar. Worry less about level. Worry more about why you have the sag, and correct that. Then, you may not have anything else to worry about.
bbcamp is offline   Reply With Quote
Unread 10-31-2009, 09:13 AM   #6
johnfrwhipple
Registered User
 
Join Date: Jul 2009
Posts: 700
Floor Sag

If you stand in the middle of the room and bounce can you feel the floor bounce?

Perhaps the floor sagged a lot and some one came along and added the girder later.

Beefing up the sub floor from below is a lot of work - you will need to cut all the pieces like CX said and then sister on 2"x4" left and right of every bay. You most likely have plumbing and electrical to deal with as well.

Rip out the old floor and start from scratch.

Like I tell the boys "Work is hard - that's why it's called work. Other wise we would all be going to 'Vacation'."

Good Luck
johnfrwhipple 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Second Floor Laundry Room! andiee22 Tile Forum/Advice Board 6 11-10-2008 10:57 PM
Laundry Room Floor larrylv Tile Forum/Advice Board 13 11-07-2008 09:16 AM
Laundry room - floor thickness Southpaw63 Tile Forum/Advice Board 1 02-07-2008 04:52 PM
Laundry Room floor project bbh03 Tile Forum/Advice Board 16 01-08-2008 12:11 PM
Shaky floor in laundry room tjbaudio Tile Forum/Advice Board 7 01-22-2006 11:23 AM


All times are GMT -6. The time now is 03:38 AM.


Sponsors

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Copyright 2018 John Bridge & Associates, LLC