Marble Floor in Bathroom

[Roberts210]

This isn't for my garage, but I figure there are some smart floor guys on here who can answer my question.

I have 95 pieces of 12X12 marble tile to install in my bathroom. This is new construction. The subfloor is 3/4" plywood over properly spaced joists.
I've seen guys use Ardex Feather Finish to level out the subfloor. Or should I lay down a layer of Wonderboard, or something simliar? Use both?

I did tile work for a living back in the 1970's and that was a long time ago, but I'm familiar with laying out, cutting and fitting tiles, but I never did marble, and I never did 12X12 tiles. I always just did the small 4" porcelain tiles.

I've seen youtube videos where guys fit little gizmo's into the joints where tiles come together to keep adjoining tiles level with each other. What's your take on using the little gizmo's?

 

[PoorOwner]

I have 95 pieces of 12X12 marble tile to install in my bathroom. This is new construction. The subfloor is 3/4" plywood over properly spaced joists.
I've seen guys use Ardex Feather Finish to level out the subfloor. Or should I lay down a layer of Wonderboard, or something simliar? Use both?

And the spacing is..? natural stone typically require the tightest spacing joists of all tiles. Marble even have it's own marble institute standards. Something like 16" apart but depends on your subfloor thickness. 3/4" would be a minimal subfloor thickness, 1/2" would be no go.. If you go on the John Bridge forum they will tell you the exact numbers for deflection limits.

Check the flatness with a level everywhere, you can get away with a little bit of extra thinset for low spots.

Typically you would use hardybacker OR ditra (much easier to use than a cement based subfloor product, although neither count as reducing deflection), the Featherfinish stuff is not as easy as they make it look, it cures quickly.

 

[Roberts210]

And the spacing is..? natural stone typically require the tightest spacing joists of all tiles. Marble even have it's own marble institute standards. Something like 16" apart but depends on your subfloor thickness.

16" apart?? I don't follow you.

.....3/4" would be a minimal subfloor thickness, 1/2" would be no go..

Yes, as I said in the initial post, the subfloor is 3/4" Plywood.

........Featherfinish stuff is not as easy as they make it look, it cures quickly.

I know I watched a buddy of mine use it on another bathroom floor.

 

[PoorOwner]

You can use this calculator to get an estimate of deflection number

http://www.johnbridge.com/vbulletin/deflecto.pl

 

[larry4406]

In new production homes that my company builds we do the following:

Ceramic foyers/kitchens - 14" TJI joists 12" on center, 3/4" tongue and grove OSB subfloor, then 1/2" cement board, then tile.

Marble foyers - 14" TJI joists 12" on center, 3/4" hem-fur plywood, then 1/2" cement board, then marble.

Ceramic in secondary baths - 1" mudset floors over 3/4" tongue and groove OSB, over 14' TJI joists (master bath 12" on center, other baths 19.2" on center)

 

[Roberts210]

Thanks PoorOwner, according to JB, I'm good to go for natural stone.

Thanks Larry. Does your company also put down some sort of membrane? What's your take on that?

 

[Zeke]

No membrane needed in non wet areas. Lay the cement board in thinset and make sure it's level. No need to add nails or screws but if you do so, wait until the thinset has cured so you don't pull the cement board down and make fish bowls. Use weights at corners if needed.

Marble is a liability in the bathroom. It stains easily so make up and lipstick have to be used with caution. It is also very slippery.

 

[Roberts210]

Thanks Zeke. I was wondering how slick it would be.

 

[Shiftless]

That's gonna be tricky. Natural stone is super brittle. A single layer of 3/4 inch ply over joists 16" O.C.... How big are those joists and what is their span from beam to beam? You don't want to do all that work and watch it crack.

Marble tiles usually have sharp edges so in a bathroom where you're barefoot, any up and down variation (lippage) results in sharp exposed edges. BAD
Wet marble is super slippery. BAD
Marble is highly susceptible to staining. BAD

Personally, I wouldn't use it. Can you return those marble tiles?

FYI: There are porcelain tiles that look just like marble. Not porous.

 

[Roberts210]

#1 grade yellow pine, 2X10's on 16" centers in the bath. Under the tub, joists were sistered together.

Span is 8.5 feet.

 

[Shiftless]

#1 grade yellow pine, 2X10's on 16" centers in the bath. Under the tub, joists were sistered together.

2x10s are very strong but what is the span? The joists are resting on beams right? How far apart are the beams? 8 feet? 12feet?
Even 2x10s on edge can flex a bit if they are not properly supported. Marble tile cannot tolerate more than a tiny flex. Even porcelain tile is more forgiving.

John Bridge says if your 2x10 joists are supported every 10 feet you'll be OK but for 12 feet span they give you a thumbs down for marble. Yes, if you double them up you will of course get a stiffer floor. I did that on a tile job in my house. Carpeted or vinyl tile floors are very forgiving with flex. Tile and stone need really stiff floors.

Edit : Sorry...I didn't see your last line about 8.5 foot span that you just added. You'll be fine!

 

[Roberts210]

Thanks guys. I am undecided on whether to return the marble. It's a color I really like and the price was excellent.

 

[BMWED]

Have marble in the bathroom, and never again. Water will etch it, along with anything else that will spill on it. It is also fairly soft and scratches easily.

 

[theoldwizard1]

16" apart?? I don't follow you.

Modern building codes sometimes allow 24" O.C or smaller joist. These are both major issue with large tiles, especially natural stone.

 

[larry4406]

Thanks Larry. Does your company also put down some sort of membrane? What's your take on that?

The only mat that our tile contractors use is when we tile the basement bath on top of the concrete slab. There they use a fracture mat by Schluter. It prevents any cracks that may occur in the concrete from telegraphing thru the tile.

http://www.schluter.com/schluter-us...ng-(DITRA)/Schluter®-DITRA-&-DITRA-XL/p/DITRA

 

[Roberts210]

Modern building codes sometimes allow 24" O.C or smaller joist....

I just re-read his original post. I mis-read it the first time, thinking he was talking about the tile spacing and width of the grout line. But I see he's talking about the joist spacing.

 

[Roberts210]

Thanks Larry4406

 

[C2 Turbo]

We are just after installing around 1000 sq.ft. of Marble tiles 18x18 (foyer/dining and the hallway) and here are few words of wisdom

1)- With newer technology (Ditra sytem by shluter) I won't recommend the previously used stuff like hardy/cement board etc.

Educate yourself about the Ditra system and make sure the guy installing it knows what goes underneath it and underneath the tile (2 different thinsets)

2)- Marble is not recommended in the bathrooms for obvious reasons already mentioned before

3)- Be careful who's installing the marble. Make sure he has installed it before

4)- Since marble is reflective, be careful about the lippage. If they are not installed perfectly leveled, you will see the lippage even if it's within factory specs.

Hope that helps.

 

[bzinsky]

For bathrooms, definitely don't use thin spacing with 12x12's, it makes it that much more slippery. I have 1/16th grout lines in mine and it's quite dangerous.

I personally like a thick cement board under any tile that's over wood subfloor. It gives it that rock solid feel, like a stone floor should feel like.

 

[black00lightning]

Have you thought about using travertine instead of marble? If you get the honed finish it will reduce the slipperiness.

 

[Steves32]

Years ago- my mother had beautiful green marble floors installed on her 4 bathroom floors. Master had a sunken roman tub- all same marble. House slab floor. Tub etched & looked terrible in just a few years. Other areas of floor started flaking off in layers. She had it ground down, polished & sealed 3 times before giving up on it. Tore it all out & went with porcelain tile.

 

[duneslider]

Empress green marble should not be used in wet areas. It doesn't like water and I have even seen it curl up on the edges.

Marble is a great material and will look great in the bathroom. However, it certainly does have some things you should be aware of. I don't have time to get into it all but here is a link. http://www.houzz.com/ideabooks/12133357/list/why-marble-might-be-wrong-for-your-bathroom

Marble has been used in bathrooms longer than porcelain has existed. If it is installed correctly and maintained properly it will last a lifetime. Like all natural products it has some inherent characteristics and it will wear with age but that just adds to the beauty of a natural product. If you want it to look brand new and high polished forever then you might be disappointed.

 

[Shiftless]

" If you want it to look brand new and high polished forever then you MIGHT be disappointed."

duneslider:
I appreciate your comic understatement!

 

[dirtrich]

Empress green marble should not be used in wet areas. It doesn't like water and I have even seen it curl up on the edges.
.

When I saw the title of this thread, this was the first thought that came to mind!
We put Empress green marble in both of our bathrooms (one just floor, the other floor and shower). Our tile guy that was doing the install told me that he had seen Empress curl up on the edges before, and that in his experience he thought that it was just certain batches of it (mined from different areas perhaps) that were prone to doing that.....BUT that he was confident that he could install it without that happening.
Going on Six plus years now, and no problem. Still looks great!
We actually have about twenty tiles we didn't use that are stacked in a shed with an open front....the tiles are in the front where they get wet from the rain every year and they are still as flat as the day we brought them home.
One product he used was called "mer-krete systems Fracture-Guard 5000", which is a liquid you roll on w. paint roller.

 

[duneslider]

When I saw the title of this thread, this was the first thought that came to mind!
We put Empress green marble in both of our bathrooms (one just floor, the other floor and shower). Our tile guy that was doing the install told me that he had seen Empress curl up on the edges before, and that in his experience he thought that it was just certain batches of it (mined from different areas perhaps) that were prone to doing that.....BUT that he was confident that he could install it without that happening.
Going on Six plus years now, and no problem. Still looks great!
We actually have about twenty tiles we didn't use that are stacked in a shed with an open front....the tiles are in the front where they get wet from the rain every year and they are still as flat as the day we brought them home.
One product he used was called "mer-krete systems Fracture-Guard 5000", which is a liquid you roll on w. paint roller.

Its like rolling the dice with Empress Green. Really pretty stuff though. Fracture guard is just a waterproofing membrane and wouldn't affect whether or not the tile had issues. A properly built shower however will dry out QUICKLY after each use and won't stay wet long term which is more likely the cause of the issues with the empress. So, chances are good your tile guy did a good job.

 

[dirtrich]

Its like rolling the dice with Empress Green. Really pretty stuff though. Fracture guard is just a waterproofing membrane and wouldn't affect whether or not the tile had issues. A properly built shower however will dry out QUICKLY after each use and won't stay wet long term which is more likely the cause of the issues with the empress. So, chances are good your tile guy did a good job.

It is really pretty stuff! We used "Moulin Rouge" for the counter, shower bench and other details......fricken gorgeous!!

 

[Roberts210]

Thanks for all the replies! Mine is not Empress Green. It is... hard to describe, but it's not white either. It's a beige/light pink with several different colors of veining. I'll do the wet test and see if there is any iron content in it.

 

[Roberts210]

I just stuck a piece in my shower. I'll leave it there for a few days and see what happens to the veining.

 

[Roberts210]

The 12x12 piece has sat in the shower for 3 days now. I don't see any rust in the veins, and it's actually not slick--it's stayed wet most of the time from multiple showers a day, and when I push my foot across it or rub my hand across it there is a definite friction feel... it's hard to describe, but it doesn't feel slick at all.

 

[Roberts210]

It HAS changed color though. It's gotten a lot darker, so I see it will absorb water.

 

[duneslider]

Everything absorbs water, even porcelain. Stone is obviously more porous than porcelain and will absorb more and as you found it can/will change color.

Typically, the polished surface will not absorb water as quickly and if you keep it sealed it won't absorb too much. I think it is best to install marble over a waterproof membrane (liquid or sheet). It will dry out quicker that way and be less likely to stay wet and absorb moisture.

Marble WILL require more maintenance than porcelain. Best method is to towel dry, or squeegee your shower and glass after every use. This will keep it looking new almost for a long long time and reduce the maintenance and cleaning. Most aren't willing to do this, me included.

 

[wellvrsd]

I installed ~105 sq ft of this tile in my master bath back in 2012. I have not noticed many of the issues that people are bringing up. Especially the slipperyness, I dry myself as I get out of the shower and don't have a problem. Are others wondering around the bathroom dripping wet? I haven't noticed any staining either, but my wife is not a big user of makeup. I do notice the lippage. I can't see it while standing, and I can't feel it when I walk on it in shoes, but I am aware of a few slightly misaligned tiles when I walk on it in bare feet. If you find yourself eight hours into tiling with a few hours left to be done saying "good enough", stop right there and put yourself to bed. Otherwise you'll be regretting not taking that one more day to do the job for a very long time.

 

[Roberts210]

That's gorgeous wellvrsd. I think I'll be able to live with this tile. I'll probably use T-locks or something like that to deal with the lippage issue.

 

[wellvrsd]

Thanks for the kind words. Those T-locks look amazing. This is the first I've heard of them, I'll definitely be getting some for my next tile project. Good luck with your bathroom.