Tile over Concrete

[Mark Kanof]

I am going to be putting down new tile in a small room about 7 X 9 with a concrete floor. The room is on the outside of the kitchen with a standard doorway in between the two. Now the problem is that the concrete is about an inch lower than the kitchen floor. I would like them to be even or at least very close.

What should I do? Put down cement board? How should I attach it? I am doing this job for a friend of my parents so I really want it to come out well. Any thoughts would be greatly appreciated.

Mark Kanof

[TDHofstetter]

Hi, Mark.

You could use standard backer board stuck to the floor with thinset mortar just like a huge tile. Another approach would be a healthy quantity of floor leveling compound. That'd even give you a super-true, flat floor to work on.

-- Tim --


Eschew obfuscation.

[Lou_williams]

lThe best and traditional method is a motor bed. that is where you would float a ~3/4 inch layer of dry mixed morton on the concrete and skreed it level and flat. then when you apply the 1/4 tile you will have a level transition. A dry mix has just enough water added to allow the motor to be tampped down and it stays. If it runs it is too wet. it will be sandy unless you press it together then it will clump.

[Mark Kanof]

Lou,

Could you explain a little more about how to put down this mortar bed. Like how to get it flat and level? I have layed tile before, but have never had to do anything this indepth so I am a bit confused and hesitant.

Mark Kanof

[Super Ry]

This thread is exactly what I need. I'm having the same problem - pantry/dining room is about 1/4 inch lower than rest of the house. The tile finally broke transitioning form the kitchen to the pantry. A little more detail on the mortar bed and I think I might be up to trying to tackel it myself.

[Billy B]

If you are going to instal a mortar bed on finished concrete, I would use metal lath in the substrate and not concrete but thinset, it will chip up sure as shootin if you don't.

If you need to use this process on a wood floor like I said in the other post regarding tile, staple metal lath to the wood subfloor with a pneumatic stapler and then spread a layer of thinset across the screen, you can then float as much thinset as you need. Let this layer cure before installing the tile. If you simply spread thinset or concrete (please, not concrete) without the lath you will have a problem in less than a year.

I would use thinset because it is flexible, and concrete is absolutely not for a floor.

Billy B.

[doo_hicky]

Although I have never done it myself I have seen it done. When I saw it done the contractor would mix up the morter and have some pipe(1/2,3/4 or whatever) laying on the floor that was to covered. What this would do would keep the morter the same thickness. This would only work on a floor that was already level. Granted you could probably use this method to aid in leveling the floor also. After the morter is put on the floor and leveled the pipes are pulled up and the impressions are then filled in with more morter.

Mike

[TheWoodMan]

Here is a good book on the subject:

http://www.builder-books.com/b-se510.html

Dave

[Super Ry]

Don't mean to steal your thread Mark, but I just had a quick question. My subfoor is a foundation. How can I level that up? The affected area was an addon I don't think it was part of the original floor plan. The attic/crawl space gave it away. An exterior wall goes all the way up through the attic and seperates the living doom and dining room.

[Billy B]

Duff Beer Man-Dude,

How far out of level are we talking about, are you talking about portions of the floor that are falling toward the edge, the center of the floor?

Need a little more information bro.

Billy B.

[Lou_williams]

Others have beat me to the answers. You should use some sort of reinforcement and lathe is easy. The pipe is the classic method of setting a reverence. Billy is right you want to use motor not concrete as the stuff. Thinset is one type, and I would use it for the tile install, but I would use a more classic motor for the base. Motor like you would use for brick or concrete block.

The screed process is to have a reference like the pipes and then use a straight edge like a 2x4 to tamp down the dry mix mortor so that it is level with the pipe.

Hope this helps.

[Super Ry]

Total drop of pantry floor is roughly 1/4 maybe 1/2 inch - its hard to tell cuz the tile is not quite even. Its noticeable in the transition from dining room to living room through the carpet too. The addition is lower than the rest of the foundation by something less than a half inch. The overall surface is level, as far as I can tell, just not as high as the rest of the house. You can feel a drop through carpet and see the difference by a line of sloped tiles in the kitchen.

The only thing I can think of is that the foundation for the addition is not as thick or compact and is droping under the new weight. This addition was done in 1995 and aside from this issue I would have never really known it was added. They even matched the brick, no line, no difference on exterior brick between old 1957 and new 1995. Is that possible? I originally thought the addition was some sort of screened in porch that they decided to enclose fully with pic windows, cuz I wasn't able to track any line between old and new.

[Billy B]

Man who knows about what folks have done to their houses...See "Horror Stories" :7

You think that foundation may be sinking away from the original foundation? How large is the gap on the transition? That bad boy would be more than the 1/2in drop at the tip compared with the threshold/transition. I would check that first, I would be amazed to see it sink proportionally throughout the slab.

A few more questions...
Did you say tile is already in there? It will be a b@#&% to chip it up if it is attached directly to the slab.

Is the problem just at the threshold where the tile is cracking?

Do you want to replace the tile? If so, what kind of flooring do you want to put in there? Depending, you could put a wood subfloor in there for carpet or hardwood flooring.

Laying tar paper and 1/2 inch OSB subfloor would insulate that concrete a little and it is really preferred if you are thinking about installing a hardwood floor, of course it would be optimum for carpet too.

Billy B.

[Super Ry]

Thanks!!
I haven't had a molment to chip up the tile - when I do I'm sure I'll have a better understanding of whats happening. The foundation might have always been lower in that area. My fingers are crossed for this.

[Billy B]

Mark,

what did you decide to do, we got a little sidetracked here, sorry.

Billy B.

[Mark Kanof]

I am not sure what I should do. My feeling is to use the backerboard put down like tiles first if people think that will work. I should explain that I am redoing this whole room, new drywall, paint, trim, tile, shelving for a friend of my parents. I am in college right now and do the work on the weekends. She is paying me, but not a whole lot.

So my dilemma is I want to do the work correctly so that it will last because that is a matter of personal integrity but I also don't feel a need to do things that might add a lot of time and effort to the job, like spreading down a layer of mortar and leveling it out.

So does everyone think that putting down the backerboard would be a good idea. It will leave about a quarter inch diffrence between this rooms floor and the kitchen floor, but I am sure the woman who owns the house will not care. She hasn't been concerned with the inch difference that is there now. All she wants it to be is nice looking, and I personally want it quality built. So I hope everyone understands how I am trying to make my decisino and not that I am just trying to get out of doing work. Any thoughts would be helpful.