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 01-23-2022, 07:55 AM   #1
lshade
Registered User
 
Join Date: Jan 2022
Posts: 4
Another subfloor prep question

Goal: I want to tile the kitchen and breakfast nook w/ 12 x 12 ceramic (was already tiled with same size ceramic on top of several layers of old flooring when I moved in, but it was a poor install and bad tile). The last layer of flooring is vinyl tiles with a million staples in them. They are tricky to remove and otherwise sturdy, smooth, and well adhered. A few questions:

Can I hammer down these staples, then put 1/4 inch exterior grade (BCX) plywood on top of the vinyl, then Laticrete Stratamat (uncoupling membrane similar to ditra) system?

I started to pull up the vinyl in one section but stopped, seeing how challenging it was and that the staples did not come up with it. There is a little less than 1/8 difference between that area and the vinyl. Again, is adding the 1/4 inch plywood throughout + uncoupling mat sufficient to deal with it? Similarly, they never installed the vinyl in the area of the range and dishwasher, but there is some other type of linoleum. Similar transition height there.

Does the plywood need to be both glued and fastened with screws? When used to make a smooth surface for uncoupling membrane and not structural support, does the wood still need to be staggered and played with 1/8 inch gap between pieces? I have a handy person "helping" and noticed he started putting wood down and did not stagger and space. Fyi I have 4x4 pieces instead of 4x8, had to cut in half to get it home.

Structural info: I have a 1947 house with 2 layers of about 1.5 inch thick total plank flooring as original subfloor, as measured from inside heat vent. Joists are about 14 inches apart. There are also diagonal wood plank supports along the joists, under the subfloor. My terms may be off here as I'm a total noob, but a pic from the basement is included.
Attached Images
    
__________________
Lindsay
lshade is offline   Reply With Quote
Sponsored Links
Unread 01-23-2022, 09:35 AM   #2
ss3964spd
Moderator
 
ss3964spd's Avatar
 
Join Date: Jul 2005
Location: Fairfax, Va
Posts: 5,093
Send a message via Yahoo to ss3964spd
Welcome, Lindsay, quite a project you have going on.

You mention there are 2 layers of plank subfloor. That would be very unusual so I have to wonder if you have one layer of 3/4" planks, installed diagonally, with the 2nd 3/4" layer being an old, probably original, hardwood floor. Regardless, there might also be an underlayment, typically 1/4" thick, upon which the vinyl flooring was installed. If the vinyl 12X12's were installed directly onto the 2nd layer of planks I think you'd see the individual planks where the vinyl has been removed.

But before we delve deeper into the flooring layers, let's find out a bit more about the floor joists so we can help determine joist deflection. Your photo of them suggests they are 2"X10" nominal (1.5"X9.25" actual). You mentioned they are about 14" apart, perhaps being 16" on center. What we don't know is how long they are. More specifically, you'll need to determine what the free span of each joist is, free span being the longest unsupported length. For instance, the joists might rest on walls only at each end, and the space between those walls could be 12'. That 12' is the free span.

So verify the actual height of the joists, how thick they are, and what the free span of each is.
__________________
Dan
---------------------------------------------------------------------------------
If I recall correctly my memory is excellent, but my ability to access it is intermittent.
ss3964spd is offline   Reply With Quote
Unread 01-23-2022, 10:32 AM   #3
lshade
Registered User
 
Join Date: Jan 2022
Posts: 4
Ok took another look and learned some terms. Yes 16" on center re joist spacing. And you are right re 2" x 10" size. There are the diagonal supports, then 8" wide x 3/4" thick planks, then 1/2" of plywood. New pic from where the flooring meets top of stairs to basement is attached. The longest unsupported length that I can see and measure is 26 feet, but the tile is only applicable to half of that. Also I somehow previously missed that there is another very thin layer of sheet vinyl under the square vinyl tiles. A cardboard like residue is left on pulling up (seen in pic in earlier post). The pics don't capture that the wood planks and plywood are a bright red color, if that tells you anything.
Attached Images
  
__________________
Lindsay

Last edited by lshade; 01-23-2022 at 10:46 AM.
lshade is offline   Reply With Quote
Unread 01-23-2022, 10:44 AM   #4
ss3964spd
Moderator
 
ss3964spd's Avatar
 
Join Date: Jul 2005
Location: Fairfax, Va
Posts: 5,093
Send a message via Yahoo to ss3964spd
A 26 foot free span, Lindsay, are you certain? Are there any walls in the basement that run perpendicular to those joists, that the joists rest on?
__________________
Dan
---------------------------------------------------------------------------------
If I recall correctly my memory is excellent, but my ability to access it is intermittent.
ss3964spd is offline   Reply With Quote
Unread 01-23-2022, 10:55 AM   #5
lshade
Registered User
 
Join Date: Jan 2022
Posts: 4
There are 3 joists that have a 26 ft span except I just looked again and there is a perpendicular support beam at 12 ft, but it does not go floor to ceiling. Still, most of the room I am working in is actually over a crawlspace that I cannot currently access.
__________________
Lindsay

Last edited by lshade; 01-23-2022 at 11:28 AM.
lshade is offline   Reply With Quote
Unread 01-23-2022, 11:01 AM   #6
lshade
Registered User
 
Join Date: Jan 2022
Posts: 4
Pic of support beam

(I look forward to cleaning up the nightmare of random cables and wires someday)
Attached Images
 
__________________
Lindsay
lshade 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
Low-Quality Subfloor Prep Question Analise Tile Forum/Advice Board 3 03-10-2018 09:00 PM
Question on proper subfloor prep cruzmisl Tile Forum/Advice Board 15 04-05-2013 07:23 AM
Subfloor prep question welch7104 Tile Forum/Advice Board 9 04-18-2007 04:42 PM
and another subfloor prep question......... ikesdad Tile Forum/Advice Board 2 04-03-2007 11:03 AM
Subfloor prep question, an easy one!?! Ryanthenewbie renovator Tile Forum/Advice Board 6 12-12-2003 10:41 AM


All times are GMT -6. The time now is 02:53 PM.


Sponsors

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