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 04-18-2022, 07:55 AM   #1
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
Tim's Kitchen Renovation Thread...

Hi, all:

My name is Tim, and it’s been a long time since I’ve posted here (2009, I think). We are in a new house since then. I am beginning a gut rehab of my kitchen and downstairs bathroom, and I’m starting a thread on it. My first question involves floor preparation for porcelain tile.

A but of background; my house is built in 1897, and originally had wood floors throughout. The floor structure is as follows: joists are nominally 2X10, but measure out to between 9 and 9-1/4 inches deep, 1-3/4 to 2 inches wide. Spacing is 16 to 18 inches (not consistent), and the span is 13 feet, 8 inches. Wood is unknown, but it appears to be pine or fir. Condition is OK.

On top of this is the original floor, which is ¾-inch by 2-inch quartersawn, T&G planks, again either pine or fir.

I put the worst case scenario in the deflect-o-lator, and it returns L/246. So, I am planning to put a two 2X12 header in the basement with a couple of lally columns. This should cut the maximum span to 9 feet or less, giving L/711. This is probably overkill, but I want this floor stiff and stable to protect my investment.

Now, the big question is subfloor prep. The area has tile in it today. It’s a 6X12 natural marble. It has cracked in a number of places, and I think this particular floor is about 20 years old. There is one tile that popped up, at the foot of our back stairs where my kids like to jump off the last step.

My original plan was to take the tile and all the subflooring out back to the original plank floor. Then go over that with new ¾-inch plywood T&G subfloor, then ¼-inch Wonderboard bedded in thinset, then my new tile.

However, I started doing some exploratory demo on the floor this weekend and ran into a possible snag. As best I can tell at this point, here is what I am dealing with:
  • On top of the original plank floor is a layer of ¼-inch luan, secured by what looks like cut-back adhesive and some liquid nails. It appears to be nailed down with ring-shank nails about every 12 inches (it seems clear that this was a base for sheet vinyl at one time).
  • On top of the luan is ½-inch plywood that is glued down with copious amounts of liquid nails, and nailed with ring-shanks every 6 inches.
  • Tile is applied with thinset directly on the plywood.

The tile comes up very easy, and most of the thinset comes right off the plywood. The problem is the plywood and the luan underneath. I pulled up about a 6 sq. ft. section, and it basically came up as splinters, due to the glue and nails. (See pic.)

So, I am wondering if I need to pull all of this up, or if I can pull the tile, make sure the ½-inch plywood is clean and smooth of all thinset, and then screw down *another* layer of ½-inch plywood, then my ¼-inch Wonderboard, and then my tile.

I want to do this right and I want it to last forever. If I need to sweat through pulling all this glued plywood, so be it, but if that is unnecessary work, I don’t want to do unnecessary work! I’ve got about 225 square feet of this to do in total.

Also, the new tile will be a mix of mosaics (some mesh-mounted, some cut and arranged by me), with 8X8 field tiles and 12X24 field tiles. All tile will be porcelain.

Thanks all for your advice and guidance!

Best,
Tim
Attached Images
 
__________________
Tim
tbreihan is offline   Reply With Quote
Sponsored Links
Unread 04-18-2022, 05:53 PM   #2
PC7060
...unrepentant, detail focused, over-analyzer.
 
PC7060's Avatar
 
Join Date: Jan 2013
Location: Virginia
Posts: 2,994
I can’t be certain from the one picture you show but often times it is often easier to just remove it down to the joists and add a new subfloor. I spent a couple long weekends trying to fix a bad floor in small bathroom a few years ago before removed and replace the subfloor after flattening the joist.

The second bathroom I did in that house I stripped it down to the joist, reframed the bad sections andaid the subfloor in a weekend. Much less headache second time.

Good luck!
PC7060 is offline   Reply With Quote
Unread 04-19-2022, 08:05 AM   #3
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
That is a solution I hadn't really considered. Once the tile is up, I could pretty easily cut through all the layers of the floor assembly along the joists from below with a sawzall... I big mess, for sure, but a lot less back-breaking labor than pulling up the glued-down plywood.
__________________
Tim
tbreihan is offline   Reply With Quote
Unread 04-19-2022, 05:45 PM   #4
PC7060
...unrepentant, detail focused, over-analyzer.
 
PC7060's Avatar
 
Join Date: Jan 2013
Location: Virginia
Posts: 2,994
Exactly! And learning from someone else’s mistake is always better than experiencing first hand!
PC7060 is offline   Reply With Quote
Unread 04-22-2022, 03:28 PM   #5
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
Alright, so I am most likely going to strip everything down to the joists and replace the subfloor, as PC suggested. When looking at subfloor options, most of the local places carry primarily 23/32 T&G OSB subfloor. They all have a few sheets of 23/32 T&G plywood subfloor, but it looks like the bottom of the barrel.

What are the pros and cons of each? Should I even be considering the OSB subfloor? For reference, I am still planning to put a second layer of 1/2 plywood on top of the 23/32s, and then 1/4 CBU backer board, bedded in thinset.

Thanks!
__________________
Tim
tbreihan is offline   Reply With Quote
Unread 04-22-2022, 04:38 PM   #6
cx
Moderator emeritus
 
cx's Avatar
 
Join Date: Jul 2001
Location: Boerne, Texas
Posts: 95,473
In your proposed package it would make no difference to me at all whether I used OSB or Plywood for the first layer, so long as it had T&G edges. I would want plywood for my second layer, but when using CBU as your tile substrate, the difference wouldn't really matter there, either. And that layer need not have T&G edges.

My opinion; worth price charged.
__________________
CX

Y'ALL NEW VISITORS READ THIS HERE!
cx is offline   Reply With Quote
Unread 05-11-2022, 11:01 AM   #7
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
Another subfloor question... options and recommendations

Making slow progress with demo and some corrective framing repair to the second floor above my kitchen. I'll try to post pictures soon!

I have a specific question about the recommended subfloor treatment for the kitchen floor. To summarize, my current floor structure is old 2X10, 13'4" span, unknown wood, with spacing varying up to 18" O.C. The deflectolator, using worst case conditions, returned >L/250.

I am going to add a (2) 2X10 mid-span beam in my basement with three columns. This beam should have a deflection of less than L/3739 with a heavy, conservative 75 psf floor load. My overall floor deflection should be L/500 or less.

I am replacing the subfloor down to the joists, and it seems like I have a couple of options. I would like your advice on the best approach.
  1. Option 1: Advantech "OSB" subfloor, 23/32 T&G (which all the homebuilders say is the stiffest, strongest subfloor), plus 1/2" non-T&G plywood, plus 1/4" Wonderboard bedded in thinset. (Advantech is expensive at $83 per sheet, but I would be curious to know if its worth it.
  2. Option 2: Plywood subfloor, 23/32 T&G, plus 1/2" non-T&G plywood, plus 1/4" Wonderboard bedded in thinset. (Plywood subfloor ranges from $77 to $87 per sheet, depending on foreign vs. USA plywood.)
  3. Option 3: Generic OSB subfloor, 23/32 T&G, plus 1/2" non-T&G plywood, plus 1/4" Wonderboard bedded in thinset. (Cheapest option at $40 to $60 per sheet, but questionable quality.)

I understand that all of these are acceptable solutions for tile, but this is my kitchen, and I want a rock-solid floor that will last the rest of my life and longer (house is 125 years old at this point, and I want to do this right and do it permanently). So, I am not opposed to paying more for the best product that gives me the strongest floor. However, I also don't want to waste money if there is no advantage to spending more.

Also, if I were to use the Advantech, would I NOT need to use the second layer of 1/2" plywood under the Wonderboard? That would certainly save on cost, but more importantly would reduce the difference in floor height between the tile kitchen and the wood floor in the dining room.

As always, experience and advice is most appreciated!

Best,
Tim
__________________
Tim
tbreihan is offline   Reply With Quote
Unread 05-11-2022, 11:31 AM   #8
cx
Moderator emeritus
 
cx's Avatar
 
Join Date: Jul 2001
Location: Boerne, Texas
Posts: 95,473
Depends upon your risk tolerance, Tim.

The nominal 3/4" over joist spacing of 16" or less exceeds all tile substrate manufacturers' recommendations. Over 18" joist spacing, you're on your own. Would it work? Maybe. Single layer nominal 3/4" subflooring will pass the Robinson Test (ASTM C627) most of the time over 16" centers with zero joist deflection.

The second layer of subflooring should give you a substantial comfort margin and I would recommend it. That would apply with the least expensive OSB for your first layer. If you can deal with the extra thickness, that would be my choice.

If you elect to try the single layer, I'd go with the Advantech.

My opinion; worth price charged.
__________________
CX

Y'ALL NEW VISITORS READ THIS HERE!
cx is offline   Reply With Quote
Unread 05-11-2022, 04:19 PM   #9
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
That's good advice, CX. I appreciate it!

The extra thickness is no big deal, and I am more concerned about having a stable, long lasting floor. As I may have mentioned earlier in the thread, I'm investing over $35K in this complete gut rehab, so an extra $1K or so in flooring materials is really not that big a deal in the scheme of things.

So, with the extra 1/2-inch plywood--in your opinion--does it really matter what the nominal 3/4" T&G subfloor is? Is there any difference between standard OSB/plywood/Advantech in that situation?

Thanks!
__________________
Tim
tbreihan is offline   Reply With Quote
Unread 05-11-2022, 05:03 PM   #10
cx
Moderator emeritus
 
cx's Avatar
 
Join Date: Jul 2001
Location: Boerne, Texas
Posts: 95,473
Probably is a measurable difference, but I would disregard it were I making a double layer subfloor.

Here is a good article from our Liberry showing what I think is the very best method of installing the second layer of subflooring. I'd recommend you follow that to the fullest extent you can for your installation. Disregard the term underlayment, it's a second layer of structural subflooring.

My opinion; worth price charged.
__________________
CX

Y'ALL NEW VISITORS READ THIS HERE!
cx is offline   Reply With Quote
Unread 06-08-2022, 02:19 PM   #11
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
Making progress...

I need to post some pictures, but I am making slow progress on this very large (for me) project!

I've cut out and replaced about a third of the subfloor in the kitchen/bath area (I'm working in sections in order to keep the kitchen functional for as long as possible). About 65 square feet of subfloor has been replaced. I opted to use 23/32 GP Plytanium Dry-Ply from Menard's. I've been doing corrective framing repairs and installing new blocking as I've demo'd the floor. I'm installing the new subfloor with PL Premium 3X construction adhesive and 3-inch screws at 6" O.C. I'm impressed at much more stable the new subfloor feels compared to the old.

Next steps are to install my supplemental, mid-span beam (to minimize the overall floor deflection), and then start on framing out the new bathroom and butler's pantry partition walls. After this, I will start installing the second layer of structural subflooring.

CX, thanks for the link to that article! I am familiar with that article, and that was my original plan as well. I have two questions about this second layer:
  1. First, I am planning to use this CC, pressure-treated plywood from Menard's for my second layer. I am correct that this meets the article's requirement of "Exposure 1, plugged-face plywood"?

  2. Second, do I install this layer using screws only, according to the fastener schedule provided in the article (4" O.C. edges, 4" O.C. both directions field), or should I use both screws AND construction adhesive under this layer?

Thanks again for all the guidance and advice!
Tim
__________________
Tim
tbreihan is offline   Reply With Quote
Unread 06-08-2022, 02:28 PM   #12
cx
Moderator emeritus
 
cx's Avatar
 
Join Date: Jul 2001
Location: Boerne, Texas
Posts: 95,473
1. I would recommend you not use that, or any other, pressure treated plywood in your subfloor. You should be able to find an AC or BC exterior glue plywood at your local home center.

2. I believe the article cites 4" edge spacing and 6" field spacing for nominal 1/2" plywood second layer. I personally think 6" and 8" spacing is sufficient. See my warranty information below.

I would recommend you not glue the layers, but if you do you should use a full spread of wood glue, not a construction adhesive from a gun tube.

My opinion; worth price charged.
__________________
CX

Y'ALL NEW VISITORS READ THIS HERE!
cx is offline   Reply With Quote
Unread 06-23-2022, 11:01 AM   #13
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
Progress pics...

Finally getting around to posting some pics!

Starting with demo...

First pic is where our oven used to be!

Second pic is some of the questionable work I found behind the bathroom drywall.

Third and fourth pics are with all of the bathroom wall framing removed.
Attached Images
    
__________________
Tim
tbreihan is offline   Reply With Quote
Unread 06-23-2022, 11:06 AM   #14
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
First pic here is corrective framing to the floor ABOVE the kitchen. This is a bathroom, and I am really surprised that this floor didn't fail, given how badly the joists were hacked up.

Second pic is more corrective framing, this time under the upstairs toilet.

Third pic is the beginning of the removal of the floor assembly, which is plank flooring with 1/4 inch luan on top with 1/2 inch plywood on top of that.

Fourth pic is of one of the three (3) new footing holes for the new mid-span, supplemental beam.
Attached Images
    
__________________
Tim
tbreihan is offline   Reply With Quote
Unread 06-23-2022, 11:10 AM   #15
tbreihan
Registered User
 
Join Date: Sep 2009
Location: St. Louis, MO ("a drinking town with a baseball problem")
Posts: 41
Pics one and two... new subfloor! Here is the 23/32 Plytanium DryPly, secured with PL Premium 3X adhesive and 3-inch nails at 6" O.C.

Pic three... here is my laminated 2X10 beam, in position on top of scaffolding. 15'6" long and, unbelievably, I was able to get it on top of that scaffolding myself!

Pic four... beginning the jacking process, with lots of diagonal bracing for stability. The beam weighs about 350 lbs.
Attached Images
    
__________________
Tim
tbreihan 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
Kitchen renovation Oldrem Tile Forum/Advice Board 3 04-04-2015 05:52 PM
Andy's Kitchen renovation #2 Andrew21 Tile Forum/Advice Board 46 02-10-2014 11:36 PM
My first big project - Kitchen renovation Tomace Tile Forum/Advice Board 37 05-10-2011 06:11 PM
Joe's Kitchen Renovation DetRedWingNut Tile Forum/Advice Board 1 11-19-2009 01:24 PM
Kitchen Renovation - New Tile Rob13 Tile Forum/Advice Board 28 03-04-2008 01:14 PM


All times are GMT -6. The time now is 05:10 AM.


Sponsors

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