Thinset on Concrete

[lrd9999]

I assume this is reasonably old concrete. I see some comments about cracks, but I'm surprised no one has mentioned shrinkage. My understanding is that concrete shrinks for the first 30 years of its life, so if you try to tile over new concrete, you need some kind of slip-mat, floating backer-board or really flexible grout. Otherwise, you'll get that dreaded "hollow bulge" in the middle of the floor.

[AsktheBuilder]

@lrd9999 The concrete was about 8 years old. If you want to discover the *truth* about concrete shrinkage, go to my AsktheBuilder website. It's a dot com. Type: concrete shrinkage into the search engine. You'll be blown away by what you'll discover.

[chevpowr]

ALWAYS back butter the tiles with thin set. That will make sure it is a 100% bond. Its especially important with porcelain and stone.

[feedphillipnow]

Great video! I've seen a lot of people putting down a board first and not direct to the concrete, when is that needed? I am doing a kitchen and dining area soon and would like to do it how you've done here, great method!

[thanhtran5]

Another great video!

[overlordetna2]

Thanks for the video!

[tonlo2006]

your so wonderful thank you

[Solarpassive]

Tim, I made a suggestion previously. Here is another. The more parallel your lines of thin set are, the more air that can escape. The way you are doing that, there will be areas where air will not be able to escape. Try this. Take a 1 foot square of clear plastic should be sort of thick. Make your lines completely parallel and drop the tile on it. Then slide it with the lines, then against the lines. You will notice there is no air under... Try both ways and see what ya get...

[speezguy]

Tim,

Great vid. Im redoing my bathroom. The shwer/toilet are seperated with a pocket door wall and the vanity is on the other side of the P/D wall. The tile in the bathroom is all the same. The vanity area tile is attached directly to the concrete with thin set but the shwr/to area has a very thin black material on the concrete under the thin set and the thin set didn't stick well at all to it. Do you know what the black material is and how to remove it? I think the bathroom was retiled in 70's

[AsktheBuilder]

@speezguy Could be hot tar. It's not easy to remove. Chip it away with a sharp chisel.

[mderieux]

@speezguy hehehe....I probably shouldn't say this...but I have actually found that mineral spirits worked really good in getting it up. :)

[jutanat]

Thanks for vidio....^=^

[bearwoodcarpentry]

just invested in some snickers duratwill work trousers with built in kneepads and would highly recommend if you spend much time on yer knees good vid thanks Tim

[echtconservative]

Tim,

Thanks for the video. Do you use tile spacers at all, or can one do without them?

[AsktheBuilder]

@echtconservative I've done it both ways for years. In this case, I chalked lines every three or four rows to ensure I was running straight. It's best to use a combination of spacers and chalk lines in my opinion.

[HighGear7445]

Thanks for the video between helping a friend last week do my shower and your

video I felt confident enough to do my basement bath floor tile.

Things went well , got the whole family involved ,and after my next step of adding

a 4 inch kick plate and grouting I think it'll look sharp.

I watch a lot of your video's as I try to learn to do it myself, thanks,

[nate379]

Is there a reason you didn't "back butter" the tiles?

[TheWinningGambler]

how do i clean 50 years of oil and elastic adhesive in a kitchen from vinyl tiles?

[TheWinningGambler]

how much thinset mortar do i need for one 5x8 and one 4x8 bathroom?

[The03235012]

Can I mix thinset a day prior to laying it down in a 3 or 5 gallon bucket with a top seal? Some what like the ready mix.

[AsktheBuilder]

@The03235012 Have you taken the time to read the instructions on the bag of thinset? The answer is No - unless you add in a retardant.

[fred30680]

Well you make it sound easy. I have a slab house. Which means the tile is going onto a concrete floor. In your video you said you do not have any cracks. Well we do and its a BIG one, so what do we do ? We are doing a large area. I know there are low spots and high spots. Hows the best way to get around that problem ?

[AsktheBuilder]

Go to my AsktheBuilder website and read my columns about epoxy crack repair for concrete slabs. Then read my columns about self-leveling floor compounds.

[123temoblanc]

great video man ,, you save me a pair of hundres bucks, thanks.

[ciren10]

Can I put tiles over the painted concrete floor?

[AsktheBuilder]

Yes. Make sure the floor is clean. You better go to my AsktheBuilder website and read ALL my past columns about installing tile.

[bulbulz44]

you never heard of primer ?

[AsktheBuilder]

Sure. Great product. But this is showing that a clean concrete slab that's slightly damp will give you a bond as good. Water is cheaper than primer. :->

[Vervello]

Hey Tim. Just want to thank you for your clips. I have been looking a few and they're sure great to me. Nice going.

[AsktheBuilder]

Thanks! Please help spread the word about them.

[sophiat85]

Can I use the same method on cement floor?

[AsktheBuilder]

Uh, yeah.... :->>>> I show in the video applying it to a concrete floor. On your monitor does it look like wood? I'm asking as I thought it was very obvious that the substrate was concrete.

[sophiat85]

no...not really, I'm asking this because many of my friends telling me that I should make some holes on the cement floor before installing the tiles. According to them, this will make the tiles more firm as well as crack proof. I wondering is that true?

[AsktheBuilder]

They are giving you bogus information. Follow what I say in all the videos I have about installing tile. There are several.

[bulbulz44]

thats bullshit.I am a tiler and water stops the glue from sticking to the floor.You have to use primer dorkface.

[AsktheBuilder]

I must be in a great mood today. Normally I would have deleted a comment like this because it adds no value. But your lack of education about the hydration chemical reaction that happens when thinset cures made me publish your comment. I want to educate homeowners out there to show them that there are bogus *professionals* out there that really think they know how to install tile the correct way. Sadly, you're one of them. Go Google: hydration reaction concrete and become a real pro.

[datzfast]

its true concrete does not cure by drying, in fact its better to keep it moist during cure to prevent cracking. the co2 lost during the manufacture goes back in only when the co2 from air if disolved in water.

[lukekurik]

if your using an unmodified thinset yes hydration does make the thinset stronger. Modified thinset hydration reaction is not applicable. Ideally you should mop the concrete floor and let it dry. I would be worried that the thinset will dry before the water you put on the floor does. Try an experiment... wipe your trowel with water and then try to get thinset out of the bucket. How good does it stick to the trowel when its wet as opposed to dry?

[seephor]

Great tip on damping the concrete before the thinset. This same rule applies putting the 2nd or 3rd coat of drywall mud over freshly sanded joint compound. The fine dust will prevent the new layer from sticking well and could chip off.

[grippingbeast]

Hi Tim. Thanks for the great, informative videos! I'm a fellow Ohioan!

I have a couple questions;

I am laying ceramic floor tile in a kitchen on top of cement backer board (HardiBacker). Should I wet it with a sponge the way you did here on the concrete?

My backer boards are all layed down in thinset, and screwed into the plywood subfloor. There is 1 piece that is a little higher than the adjacent board, less than 1/8". Should this be problematic, or with the mortar for the tiles level it out?

[AsktheBuilder]

You mean former Ohioan... I'm now a resident of the great state of NH - Live Free or Die.

Yes, wet the backer board.

[pasther1975]

May I ask you a question here what kind of adhesive would you recommend to put some ceramic tiles on a plywood floor It's not a new floor and we first leveled all the floor

thanks again I'm a huge fan of your work !

[AsktheBuilder]

Thinset. NEVER use organic mastic for floor tile. Be sure you go to my AsktheBuilder web site to READ all my columns about Ceramic Tile and Wood Floors!!!!!!!

[wyseguy77]

DO NOT SET TILE STRAIGHT OVER WOOD!!!!

Especially with thin set. Wood expands and contracts with moister and thinset is not raited for this type of installation. Also wood is not a stable substrate to set over as it may result in cracks. If you must set over wood I would use a epoxy mortar or better a water proof crack isolation like Mapie HPG. It will save you money and a head ache in the long run.

[AsktheBuilder]

I hate to tell you this, but thinset is rated for wood floors. You're correct about wood being hygroscopic. Just follow the guidelines set out by the Tile Council of America. They approve tile over wood if you do it the way they say.

[cantstopdakidd]

Hi I am laying tile on my concrete floor but what is the easiest way the removal the thinset between the tile and its a big room.

[wtawhite]

Are you saying that a crack isolation membrane should be installed (and allowed to dry) before spreading the thinset and installing the tile?

I guess these products are available at the home improvement store?

[AsktheBuilder]

Yes that's correct. Just follow the written instructions that come with the membranes. Usually sold at tile stores, NOT home centers.

[cheyiennerascal]

What is the difference between modified and non modified and does it make a difference what the tile is made of, and what is poly modified thin set.

[AsktheBuilder]

Great question to ask the Thinset manufacturers!

[aardvarkhero]

Good video, very helpful - but here's some questions -

I just layed 12"x12" porceline tile in a 13'x13' area. It was on a single slab of concrete, just as discussed in this video. I made the mistake of back-buttering each tile which made the project take considerably longer and also made it difficult to level. Will this effect the performace of the tile? Keep in mind the back buttering was also notched and the tile was layed perpindicular to the notches on the floor.

[AsktheBuilder]

Buttering can be a huge mistake. Any void spaces under the tile lead to tension when loaded with weight. Too much weight and you get cracks. Had you installed a self-leveling compound so the entire floor was in the same plane before you started, you could have spread the thinset as I show in my videos. Spread evenly the tile floor would have been perfect as the tile would then be parallel with the leveling compound.

[frijolero01]

couple of questions:

1. We started laying tile down but it seems as though there are other little intricacies that go along with laying the tile like making sure the height of the tile is aligned with the other tiles. Is this something to take into account?

2. We also "butter" the back corners of the tiles with a little thinset before laying it down. Is this also a recommended approach? thanks

[AsktheBuilder]

It sounds like your floor is not in the same plane. That's a no no.

When the floor is in the same plane and you have the correct-sized notched trowel, there is no need for the buttering.

Use self-leveling floor compound to get floors in the same plane and level.

[Rufo297]

You forgot a tiny tip

wipe the back of the tile with the sponge

before installed.

[AsktheBuilder]

That is a good tip, especially for tile that has a matte finish on the underside. Thanks for sharing.

[steeltears]

I used to do the same thing as a bricklayer. Wet part of the brick/stone and then apply the morter...allows for a better stick.

[nacuevas]

your videos are great i just subscribed, im about to move in to my first apartment and it needs lots of work but with your videos im going to save lots of money doing this myself, so thanks and keep those videos coming

[burlshard]

I have removed ceramic tile floor and I am having a very difficult time getting the thin set off the concrete. A scraper was not nearly able to remove it and then I tried a hammer and concrete chisel. This was nearly impossible too. Any suggestions?

Thanks,

Jim

[AsktheBuilder]

Patience and more pounding.

[wishonjk]

I have a concrete slab that was poured about 27 years ago. We have removed the old carpet and glue but found that the floor has some dips in places. What do I do to prepare the floor so the tiles don't crack?

[AsktheBuilder]

USG makes a self-leveling underlayment compound for this exact purpose.

[DIYsharkey]

We've used that compound when installing tile into our bathroom when redoing it. It helped a lot! I'd recommend it! Although very time consuming, like most of these products, it helps a lot.

[remoman]

why is your notched trowel brand new? HAHA!

[AsktheBuilder]

Great question! Because my old one is in Cincinnati, OH at my other house. I need it there for a project that starts in two months.

[Reed12223]

i love your videos! and for some reason i also love when you finished applying the thinset and it made that cool pattern hahaha

[CanadianToolGuy416]

great tips TIm, keep em coming

[starlite528]

There's a product I remember that you can use to cover the entire surface of your garage. It's basically concrete, but supposedly it levels out and gives a really nice flat surface so you can put an acrylic or epoxy coating in. Do you know anything about this stuff? Or concrete floor coatings?

[arnXboxElite]

do you have to clean the bottom of the tile?

[AsktheBuilder]

Rarely. Usually out of the box they are squeaky clean.

[MikeButlerMedia]

OK, there's no problem with the tiles, they aree clean (if new) but what about the mastic residue left on the floor after pulling up linoleum? Is it a problem if I don't get it completely off?

[AsktheBuilder]

Get it off.... Use adhesive remover. Good luck to you. Clear on your final.

[MikeButlerMedia]

Roger that, much thanks, out.

[MadBadVoodo]

Five Stars!!

[Shanyob]

its needfull and usefull, thanks for you and for your support team if you have.