Bump In Underlayment - 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 02-02-2008, 06:40 AM   #1
Member
 
Join Date: Feb 2008
Location: NEPA
Posts: 557
Rewards Points: 500
Default

Bump in underlayment


I laid 2 layers of 1/4" dura board over 3/4"rough sawn sub floor. Used thin set between each layer.After laying out the initial pattern I noticed a slight unevenness(1/8" to 3/16") in a few 18"x 18" tiles I am installing.Can I just go with thin set to level it all out with out any cracking of tiles in the future? Thank you in advance.

Advertisement

mark942 is offline   Reply With Quote
Old 02-02-2008, 11:31 AM   #2
Tileguy
 
JazMan's Avatar
 
Join Date: Feb 2007
Location: Troy, Michigan
Posts: 4,187
Rewards Points: 2,232
Default

Bump in underlayment


Mark,

Too bad you didn't ask questions before you started instead of now.

What you've done so far is wrong.

First you NEVER install any CBU direct over plank subfloors. You should have install plywood first then your 5/16" thick Durock.

The substrate has to be very flat for tile, especially with large tiles like that. You're always going to have some lippage, but 1/8 or 3/16" is a lot! Thinset can be used to fix a small area, but not an entire floor. Depends if you have one small depression or a peak.

If you can get the floor flat by using SLC's or Portalnd based patching cements, AND if your subfloor framing is up to speed for tile, I might say just go ahead anyway in spite of the lack of proper underlayment? (at your risk of course)

The basic standard for floor flatness is within 1/4" in 10 ft, AND 1/16" in 12" of required plane. With large tiles like yours I would like within 1/8" in 10 ft, especially if the tiles are smooth and shinny. You also need special thinset, not your basic stuff.

Go measure and tell me: the type, size, species, grade and the unsupported span of the joists. Also when was this house built and where is it?

Jaz

Advertisement

__________________
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
Old 02-02-2008, 02:18 PM   #3
Member
 
Join Date: Feb 2008
Location: NEPA
Posts: 557
Rewards Points: 500
Default

Bump in underlayment


Figures I did it wrong. I was told to do it this way in a home depot seminar. When I was told this I had to ask twice just to make sure I understood. My own thoughts were to use 5/16 plywood, then use the good old cement board or ( Wonderboard) for my underlayment. As to my Joists. 12" OC rough cut 2" x 12" # 1 Pine. The span to bearing wall is 12`. House was built in 1981,,,,,,Hence the #1 Pine. The bump I am talking about is just one tile. The rest of the tiles seem to be laying flat. My question has been answered by you with the mention of @ own risk. The thin set I am going to use is #2 modified. Longevity I guess will be time telling. Thank you again. (Pennsylvania)
Mark
mark942 is offline   Reply With Quote
Old 02-02-2008, 03:54 PM   #4
Tileguy
 
JazMan's Avatar
 
Join Date: Feb 2007
Location: Troy, Michigan
Posts: 4,187
Rewards Points: 2,232
Default

Bump in underlayment


Mark,

Attending a 'How-To Class' at one of those big box stores was your first mistake. You have to know what you're talking about to teach others. This is true in MOST cases with tile, not too sure about other classes?

I don't know what #2 thinset is. You should be using a medium-bed thinset mortar with a large notched trowel, maybe 1/2x1/2 or larger? What brands of thinset can you get? Are you going to the orange place again? Aren't there any real tile shops near you?

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
Old 02-02-2008, 04:29 PM   #5
Tileguy
 
Bud Cline's Avatar
 
Join Date: Mar 2006
Posts: 10,466
Rewards Points: 2,580
Default

Bump in underlayment


I suspect the "#2 thinset" he is referring to is the Custom brand thinsets labeled for Home Depot's use. #1 is prep goods, #2 is thinsets, #3 is grouts, some dumb stuff like that!!!
Bud Cline is offline   Reply With Quote
Old 02-02-2008, 07:14 PM   #6
Tileguy
 
JazMan's Avatar
 
Join Date: Feb 2007
Location: Troy, Michigan
Posts: 4,187
Rewards Points: 2,232
Default

Bump in underlayment


You're right Bud, I remember the numbers now. Thought maybe he escaped from the orange place and went to the red-vest place and was using UltraFlex 2?

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
Old 02-07-2008, 06:18 AM   #7
Member
 
Join Date: Feb 2008
Location: NEPA
Posts: 557
Rewards Points: 500
Default

Bump in underlayment


Flexbond thin set which is fortified is what was suggested for me to use.Dura board is the underlayment I was also directed to use.All of which is new to me.Cement board and medium bed thinset is what I am familiar with.Thats use with 2 tile floors I have done in the past.Thought I would get past the "Teach a old dog a new trick" statement.Framer by trade here gents,by the time tile gets in a building I am 1/2 way through another job........ So now I am sitting here with thinset not worthy,underlayment that doesnt level out the floor,1/8 to 1/4 notched trowels,Which are to small and a Wife that is wondering when I am going to finish the bathroom................

Advertisement

mark942 is offline   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
Tile underlayment - mortar bed question Richo Flooring 10 01-01-2008 06:54 PM
Subfloor vs Underlayment indignatz Remodeling 6 12-01-2007 03:19 PM
Hardwood floor installation on 2nd floor - underlayment necessary? digexpressions Flooring 2 11-30-2007 11:15 AM
laminate floor underlayment installation? KUIPORNG Flooring 1 03-08-2007 06:52 PM
Underlayment for laminate dm62 Flooring 3 04-02-2005 11:56 AM




Top of Page | View New Posts