Best adhesive for plywood to concrete floor

user59291 · 08-05-2009, 12:41 PM

I have a concrete floor that needs re-covering. I plan on using 12" square floor tiles for this. The present linoleum is glued directy to the concrete. Parts of it are wearing through and loosening. 80% of it is secure to the concrete.
I want to put down a wood sub-floor first. I have purchased 1/2", very smooth plywood for this.
I need to know the best adhesive to use for gluing this plywood to the concrete/old linoleum.
Please don't tell me to remove the old linoleum first. I've been told this by many. But the truth is, I've tried that and it is stuck quite well. So part of the wood will need to stick to cement and part of it to the old flooring.

Thoughts?

Thank you!

Web

HABSFAN2006 · 08-05-2009, 12:55 PM

wow, do people actually glue plywood to concrete?
How long will this last?

I do know that tons of people use tapcons to secure plywood to concrete.
In this case, your vinyl floor is kind of acting like a vapor barrier.

mpoulton · 08-05-2009, 03:36 PM

Quote:

Originally Posted by weber

I have a concrete floor that needs re-covering. I plan on using 12" square floor tiles for this. The present linoleum is glued directy to the concrete. Parts of it are wearing through and loosening. 80% of it is secure to the concrete.
I want to put down a wood sub-floor first. I have purchased 1/2", very smooth plywood for this.
I need to know the best adhesive to use for gluing this plywood to the concrete/old linoleum.
Please don't tell me to remove the old linoleum first. I've been told this by many. But the truth is, I've tried that and it is stuck quite well. So part of the wood will need to stick to cement and part of it to the old flooring.

Thoughts?

Thank you!

Web

Wood is a non-ideal substrate for tile. It moves as it absorbs/releases water, and just doesn't have the dimensional stability to resist cracking the tile over it. When a tile floor must be installed over wood, layers of hardibacker or similar masonry board are laid down first to provide dimensional stability. So, why would you want to take a perfectly stable masonry substrate and add wood over it before tiling? Instead, install a layer (or preferably two) of 1/4" hardibacker on your slab and tile over that. Secure it to the existing floor with mortar or mastic AND masonry anchors.

Maintenance 6 · 08-05-2009, 04:41 PM

I beleive the OP is talking about vinyl tile. I think it would be better to adhere these to the concrete floor, than to add a layer of plywood over the concrete. Adhering plywood directly to concrete does not provide a barrier to stop moisture from absorbing into the plywood. Wood and concrete don't play well together without a moisture barrier.

JazMan · 08-06-2009, 01:16 AM

Web,

You're wasting your time and money, what you plan to do is all wrong.

Plywood direct on concrete will not work very well, especially if you just try to glue it.

Jaz

pinwheel45 · 08-06-2009, 07:54 AM

Quote:

Originally Posted by JazMan

Web,

You're wasting your time and money, what you plan to do is all wrong.

Plywood direct on concrete will not work very well, especially if you just try to glue it.

Jaz

An elastomeric coating, followed by bostics best will provide a moisture barrier & good adhesion to the concrete. But you'll be adding $1.25-1.50/sq ft to the price of the job.

Heat will break the bond of the old tile glue to the concrete.

user59291 · 08-07-2009, 01:46 PM

Quote:

Originally Posted by JazMan

Web,

You're wasting your time and money, what you plan to do is all wrong.

Plywood direct on concrete will not work very well, especially if you just try to glue it.

Jaz

Inflammatory post removed

rusty baker · 08-08-2009, 08:35 AM

Plywood on concrete will deteriorate in a short time. I know it's hard work, but the right way to do it is take up what's down. Scraping is the best way. A chemical solvent remover will usually react to the adhesive on the new tile and they will come up. How old is the vinyl/linoleum that is there now? If it is linoleum, it will contain asbestos. That is another whole slew of problems.

Bud Cline · 08-08-2009, 10:17 AM

MODERATOR EDIT

Jaz has decades of experience in the business you are inquiring about and like me he also has tens-of-thousands of posts on various websites around the Internet helping DIY'ers that in some cases are loud mouths and in fact dumber than rocks. What Jaz is saying is fact my friend. His advice is valid advice and will save you many dollars and heartache if you just follow it. Jaz and I have been on some of these websites for more than ten years now offering professional advice trying to help people with their projects. We do this for free. Why I don't know. We take time from our personal evenings and weekends and our families MODERATOR EDIT. If that is too coarse for you all I can say is "Welcome to reality DIY".

Now if you want an example of some bad advice here ya go:

Quote:

An elastomeric coating, followed by bostics best will provide a moisture barrier & good adhesion to the concrete.

Here's the problem with that. You CAN NOT 100% overcoat some concrete floors. You CAN NOT seal-in the moisture that may be there and is continually trying to rise by an act of nature. That suggestion will not work in most cases. Now this poster will come back to defend his comment but I can tell you from more than thirty years of experience in this business IT WON'T LIKELY WORK. Don't waste your money.

Here's another one:

Quote:

Ill tell you right now the best product on the market, top of the line in its class, is the LINK REMOVED. Simply the best, nothing can compare to it.

That too is bull my friend. There are many great products alive and well on the market that equal or surpass Bostiks. That comment is two things. 1.)OPINION, 2.)SPAM. This guy obviously has a vested interest in Bostik.

Now if you want some advice from the real world you already have it and here it is again:

Quote:

I think it would be better to adhere these to the concrete floor, than to add a layer of plywood over the concrete.

Quote:

Wood is a non-ideal substrate for tile. It moves as it absorbs/releases water, and just doesn't have the dimensional stability

This should have been another "red flag" for you:

Quote:

wow, do people actually glue plywood to concrete?
How long will this last?

And then there was:

Quote:

You're wasting your time and money, what you plan to do is all wrong. Plywood direct on concrete will not work very well, especially if you just try to glue it.

And that sent you over the deep end. Please don't expect anyone to use their time to write you a book of your very own. Ain't gonna happen!

If you want straight to the point answers from real experience - stick around, ask your questions, we are glad and here to help you. If you are looking for someone to affirm your ridiculous approach to something forget that too. It ain't gonna happen.

NOW, I too can offer this. No one in their right mind tries to adhere plywood to a concrete floor. IT DOES NOT LAST IT DOES NOT WORK. Even Tap-Cons are a bad idea but I'm not using anymore of my time to tell you why. Just be knowing it's not a good idea either.

Here's your best overall advice in a nutshell, you should soak it up without further explanation:

Quote:

I believe the OP is talking about vinyl tile. I think it would be better to adhere these to the concrete floor, than to add a layer of plywood over the concrete. Adhering plywood directly to concrete does not provide a barrier to stop moisture from absorbing into the plywood. Wood and concrete don't play well together without a moisture barrier.

ccarlisle · 08-08-2009, 10:19 AM

uh, ahem...don't knock the Jazman...big mistake!

Look into those 24"x24" combination OSB and plastic vapour barrier tiles, I think called DriCore or something like that. Made by Cosella-Doerken. Just put them down and you have a subfloor that has air underneath.

Because wood should never be in contact with cement.

rusty baker · 08-09-2009, 09:02 AM

Sometimes I wonder why people ask advice. A lot of them decide to do their projects wrong even after being told the right way.

Bud Cline · 08-09-2009, 12:45 PM

..........well he's gone now and that's for the best I suppose. I was reloading and anticipating being banned for my next salvo.

I guess Jaz must have just pulled the covers over his head!

JazMan · 08-09-2009, 11:38 PM

WOW! Thanks for telling it like it is and at the same time giving me a little credit.

I won't go into the reason again, but makes for good reading.

No Bud, I'm not under the covers, just a busy weekend.

Jaz

HABSFAN2006 · 08-11-2009, 08:08 AM

MODERATOR EDIT
bad news from a-z.
on with our day now...

**Termite** · 08-14-2009, 09:26 AM

Gentlemen,
I cleaned this thread up and removed the name-calling, insults and inflammatory language from it. It is being brought back to the forum but is on a very short leash.
Further commentary that comes even close to anybody insulting anybody in any way will result in the thread's permanent removal and possible moderator action on offender's user accounts .
This thread has good information and very solid advice in it, which is why it is being allowed to remain in existence.