Backerboard over sheet vinyl [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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tony rico
12-27-2009, 11:24 AM
First time tiler, but have been around construction and fairly self sufficient in most home improvement projects.
Moving to a new(50 year old) house and will tile it before furniture gets there.
Have picked up wetsaw on sale, mortar mixer, hand tools...
The floor is sheet vynil over plywood with a basement underneath. Appears to be quite level and strong.
Vylil is glued down in most places. OK to put Flex bond/Versa... over the vynil and then screw the H****backer per manufacturer instructions?

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tony rico
12-27-2009, 11:28 AM
New to the forum and don't want you guys to waste time replying when the information is already there.Found a thread that generally answers my questio. But is there a benefit to using 1/2" backer instead of 1/4" since the price is almost the same?

12-27-2009, 11:36 AM
Hi Tony, welcome! There is no strength in CBU. If you need the extra height use 1/2" if not use 1/4". I would try to remove as much as the vinyl before you put the CBU down. Don't forget to use thinset under the CBU. :)

tony rico
12-27-2009, 12:01 PM
Sorry, but new and a bit confused.
1. is Flexbond a modified or unmodified thinset. The guy at HD said to use it to reduce the possibility of cracking.

Which should I use under the following conditions and how long before I can gently walk on the 12 x 12 porcelain tiles. The way the house is I'll have to climb out of a window and leave it for however long.

Subfloor topped by sheet vynil topped by 1/2" hardi backer then will install 12" poreclain tiles.

Final question, use the same thinset under the backer as between the backer and tile?

12-27-2009, 05:06 PM
Subfloor topped by sheet vynil topped by 1/2" hardi backer then will install 12" poreclain tiles.

Final question, use the same thinset under the backer as between the backer and tile?
tony rico

Why are you using the 1/2" backer board? Do you need the height.? It is not recommended to install over vinyl as you purpose. Do you know what the subfloor structure is?

Normally when installing BB over plywood, any thinset will work, and normally it is mixed thin. It is just there to fill any voids. Hammy

Brian in San Diego
12-27-2009, 05:56 PM

Please ask all your questions regarding your project on your thread. It helps minimize the confusion so people trying to help can have all the background information in one place. I merged your questions posted on another thread back to your project thread. Please add it to your favorites for future reference.

Hammy, the James Hardie installation ( instructions provide a method for installing their product over VCT.

1. is Flexbond a modified or unmodified thinset. The guy at HD said to use it to reduce the possibility of cracking.Flexbond is a modified thinset. You can tell if any thinset is modified or unmodified by looking on the bag for the ANSI standard. If it conforms to ANSI A118.1 then it is unmodified. If it conforms to ANSI A118.4 or A118.11 then it's modified. I am not buying the "reduces the possibility of cracking" statement. I would use a modified thinset to set porcelain over Hardiebacker.

You do not want to walk on tiles after they have been set for at least 12 hours and 24 would be a whole lot better. You can walk on the backerboard right after setting because it's the fasteners that hold it in place.


12-27-2009, 06:58 PM
Hammy, the James Hardie installation instructions provide a method for installing their product over VCT. Brian

Thanks Brian. For some reason I have never seen the following statement. Thanks for pointing it out for me and everyone else who might have been in the dark about it. Least today wasnt wasted, I learned something. Hammy

per James Hardy:

Vinyl and Resilient Flooring
Materials Required
1. Fasteners
• Minimum 7/8” long galvanized or polymer-coated 18-gauge chisel point staples with
• Minimum 7/8” long galvanized ring shanked underlayment flooring nails.
• Fasteners should be long enough to reach the bottom of the subfloor, but not penetrate it.
• Avoid using resin, rosin or cement-coated fasteners that can discolor vinyl flooring.

12-27-2009, 07:17 PM
Versabond is fine for under the cbu. No need to waste the $ on flex bond there.

For setting the tile, given that it's porcelain, the extra strength of flex bond sure wouldn't hurt anything.

12-27-2009, 08:01 PM
Welcome, Tony. :)

Let me start by shedding a little more darkness onna situation:

Hammy, that paragraph you quote from the James Hardi installation instructions is for installing the Hardibacker in preparation for the installation of vinyl flooring over Hardibacker, not for the installation of ceramic tile or stone over Hardibacker over vinyl flooring.

Although I'm not a fan of Hardi's instruction writing, that part's pretty clear, I think.

Now, I wish someone would show me where it says Hardibacker can be installed over vinyl flooring in preparation for a ceramic tile installation.

I don't doubt it could be done successfully, but I don't find it in the specs anywhere.

Back to you, Tony. The biggest danger in doing a tile installation over VCT or sheet vinyl flooring is not knowing what's under that flooring. Even if you fasten a CBU or Fiber/Cement underlayment well, if you're fastening over vinyl that's been laid over a thin layer of particle board or Luan plywood (very common), you still have a potential problem there.

You know what's under your current flooring?

I also see nothing about the joist structure under whatever subflooring you find you have. You checked that for suitability for a ceramic tile installation?

My opinion; worth price charged.

12-27-2009, 08:30 PM
Gee............. and here I stand corrected AGAIN!! I thought i was having a good day and CX goes and busts my bubble. darn. Hammy

PS I went back and read it again. and Cx is / was right.

12-27-2009, 08:38 PM
Just tryin' to keep things straight here inna shallow end, Hammy. Hell, I get confused enough myownself without no steenkin' help, eh? :D

Besides, you know you ain't gotta wait long to catch me in one, too. :)

12-27-2009, 08:56 PM
Hey, im glad some ones keepin me straight. Hammy

tony rico
01-02-2010, 11:02 PM
I have two Hardiebacker flyers in hand.
The foldout installation guide states "Hardiebacker cement board may be installed under or over vinyl composition tile(VCT) and other resilient flooring. For best results remove existing floor covering especially if it is in poor condition"

The Q&A flyer states
"12. Can I put Hardiebacker over linoleum or vinyl composite tile?
Yes. Hardiebacker board can go over linoleum or vynil composition tile, but James hardie does not recommend that you install Hardiebacker over cushioned vinyl. Follow Hardiebacker instructions for complete details."

"10. Is thinset required under Hardiebacker board sheets on floors?
Yes, Dry-set mortar, latex or acrylic modified thinset is specified between the Hardiebacker board and subfloor to eliminate any deviations between Hardiebacker board and the subfloor. This decreases the probability of popping or cracking tiles due to deflection and air pockets."

The more I read from the experienced, what seemed to be a simple, albeit labor intensive home project, has turned into a highly technical, precise, engineered, specialty, and scarey task.
I'm going to try to extract what seems to me to be the best advise on this forum as far as subfloor, substrate, and thinset application, keep reading but roll with my project or it won't get done. I do feel this exposure you all have granted me is an excellent experience and am greatful for it.

01-03-2010, 08:21 AM
Ok so im still confused................ Hammy

01-03-2010, 08:37 AM
Q: Can you install Hardibacker over existing vinyl flooring?

A: Of course you can!!
But don't ever do that.

There ya go, Hammy. Clear as mud?

Brian in San Diego
01-03-2010, 09:04 AM
See CX's post #9. James Hardie says you can install hardiebacker "over or under vinyl flooring" but what they don't say is whether ceramic tile can be installed over hardiebacker after an installation over vinyl (which would lead me to believe they know you shouldn't). I have no idea why you would want to install hardiebacker over vinyl flooring if you were going to install more vinyl. Notice that they caution about installing hardiebacker over cushioned vinyl. Just to confuse matters more Schluter has a method for installing Ditra over vinyl flooring (p. 9 of the Ditra Handbook ( but there are enough caveats that would prevent me from attempting it. I think the risk in either scenario outweighs the reward. Insufficient emphasis is being placed on the fact that most vinyl installations over wood subflooring include a layer of 1/4" luan. That possibility should make the thought of installing anything over it a bad idea.


01-03-2010, 09:06 AM
look back at the original post. 50 year old house.Nobody used luan or particleboard back then as underlayment. This guy has rock hard sheet goods
with fiber back installed right on ( maybe ) strip oak. The floor joist back then
were stronger than what we get today. If Hardi says thin-set,1/2" board,screws,thin-set,tile I think this would be fine.

Good luck Rico,

tony rico
01-03-2010, 09:06 AM
I'm going back up to Michigan in a few weeks and will satisfy myself as far as joist spacing, since the house has a basement I can see the bottom side of the sub floor I'm going to be tiling. Then I'll (have to) pull the floor registers that connect to the ductwork below and be able to see what's what.
If spacing is good, and thickness is good, I'll see how well the vynil is glued down. Then it will be either Hardie on top of it, or remove it and Hardie on the plywood.

Off question, so PLEASE let me know if it should be a new thread. I'm relatively new and don't want to violate the order of things:
Ductwork in the basement runs parallel and between the floor Joists, touching the underside of the subfloor I will tile. One can feel the warmth when standing over the ducts barefooted. Will the hardiebacker eliminate that warm spot that runs through the middle of the room? Any gotchas about tiling.

Brian in San Diego
01-03-2010, 09:12 AM
If Hardi says thin-set,1/2" board,screws,thin-set,tile I think this would be fine.The Hardiebacker doesn't say anything that you quoted. Here are the installation ( instructions. They say nothing about putting tile over hardiebacker after installation over VCT. They also do not recommend 1/2" hardiebacker on floors.


01-03-2010, 09:42 AM
From your Hardi instructions:

Floor Installation
We recommend 1/4” HardieBacker™ board for floor applications, unless 1/2” thickness is needed for transition.
1. Ensure subfloor is structurally sound

VCT is not sheet goods - Vinyl Comp tile

Rico, if you learn anything from this forum it's that you will never get everyone
to agree. If you are still concerned get a Hardi REP to answer your questions.

Scottish Tile and Stone
01-03-2010, 09:47 AM
if you learn anything from this forum it's that you will never get everyone
to agree.

You sure about that Chad?

01-03-2010, 10:01 AM
Read carefully what James Hardie is saying: VCT and Lino (the real stuff) is OK, cushioned vinyl is not. It's the cushion that Hardiebacker (and other backerboards) do not like. As well as that unknown underlayment CX is worried about.

Brian in San Diego
01-03-2010, 10:01 AM
Chad, you made one of the points I was trying to make. Hardie recommends 1/4" hardiebacker for floors. Here's another quote from the instructions. HardieBacker cement board may be installed under or over Vinyl Composition Tile (VCT) and other resilient flooring. For best results, remove existing floor covering, especially if it is in poor condition.Again reading the installation instructions they DO NOT say anything about laying ceramic tile over hardiebacker over vinyl (of any type). We want to offer suggestions in this forum that conform to normal practices and manufacturer's instructions. All I was pointed out is that the statement you made is not backed by the manufacturer's installation instructions.


01-03-2010, 10:59 AM
Yes,I'm sure. I agree with you.

Do they say anything about laying ANY kind of tile on top of the board?

From directions Quote;
• Install floor covering according to the adhesive and floor covering manufacturers’ instructions. Duh.

Brian in San Diego
01-03-2010, 01:05 PM
Chad, if you're interested in having a battle of wits I'm not interested. If you want to completely read and comprehend the Hardiebacker instructions and pass along useful information then I'm all for it. In answer to your question, yes the installation instructions clearly talk about "Finishing with Tile" and "Finishing with natural stone" both of which come after floor installation and wall installation of their product. After the section of covering vinyl with hardiebacker there is no mention whatsoever of covering that hardiebacker with tile or stone (only vinyl). If you can show us the section that says it's acceptable to install tile over please enlighten us all. I will say that James Hardie's writing style leaves something to be desired. If their intent was to indicate that tile could be laid over hardiebacker over vinyl then don't you think they would say so? Why wouldn't the use of hardiebacker over vinyl fall under the "Floor Installation" section of the instructions? I believe the consensus is that laying tile over hardiebacker over vinyl is not an approved method. If you want to take that risk, fine. But please refrain from encouraging our DIYers in search of help from doing the same.


tony rico
01-03-2010, 02:21 PM
First, in my ignorance I looked and asked about Vynil tile. I fact, this is sheet goods I'm asking about and so I have wasted everyone's time and I apologize for that. Got a lot of good information from the posts though, thanks for that.

But, Brian, what I quoted came word for word from two different James Hardie pamphlets whether everyone agrees with the interpretation or not. One is the Installation Guide and the other is a Question and Answer sheet.

I read a little too much into the pamphlets, and admit that I don't see anywhere where it says tile can installed over Backer board that was installed over vynil.

I just have to go back up North and see how much is involved in removing it. Doesn't seem like I have an option.

you guys can continue on but safer for all if I just read and not contribute until I'm sure about what I'm asking

01-03-2010, 04:49 PM
Tony, Dont fret over it............. least you got everyone to thinkin'.......... Maybe we can talk to a Hardi rep. Hammy

Brian in San Diego
01-03-2010, 08:02 PM

James Hardie treats vinyl composition tile and sheet vinyl products equally so there wasn't any problem in your line of questioning. I was fooled by reading the installation instructions as well. If you go back and read how the installation instructions are laid out it becomes clearer that they do not intend for anyone to put ceramic or stone tile over hardiebacker that has been installed over vinyl products of any type. (At least from where I sit that is their intention.)