Floor Tile Question

[1990C4S]

I'm hoping Trekkor or someone will chime in here:

I am replacing the tile floor in my bathroom, the total area is under 50 sq ft.

The old ceramic was on top of 1/4" underlay plywood which was nailed to the sub floor. The plywood is level with the hardwood floor outside the bathroom. I have removed all the old tile and the mortar (it was pretty easy to remove).

What is the right way to do this? I am thinking I should pull the plywood and instal cement backer board. Option two would be Ditra underlay, three would be a scratch coat on the plywood (possibly with mesh), and four would be tile on plywood.

I want to do it right (regardless of the effort involved) , AND next minimize the 'step-up' into the bathroom.

Lastly, how hard is it to lay marble (12"x12")? I have lots of ceramic experience, no marble experience....

[gr8fl4porsche]

Can't help with the underlayment question but I just finished laying 12x12 marble.

Turned out great. No issues except some broken tiles due to the veining. Choose your cuts carefully based on veins which are the weak spots.

Highly recommend installing an electric mat heat system. Everyone in the house loves the warm floor.

[look 171]

Try and get the floor as level or flush, I should say, with the finish floor on the outside and deduct 3/8" to 1/2" for the stone. Depending on how much build up is needed to achieve this, Hardibacker board can be used right on top of the plywood. If there is no rot, then screw down the plywood to the floor joist for some additional strength. Does the floor bounce? If the sub floor(plywood) isn't coming out, do you have access to get under there for some additional blocking between the joist? That will stiffen the floor a bit to eliminate bounce. Glue the Hardibacker to the plywood and tile on top of that. Another method is builder paper the whole floor and screw down Hardibacker to the subfloor and make sure you get a few screws (long suckers and not drywall screw) on the joist for a better installation. if the floor is nice and level without dips, then you are ready to set the stone. Fill the dips with self leveling compound if there are any.

Setting stone is just like setting regular tile. Make sure you use the correct thinset. In general, Mapei is what we use with great result. GEt us a photo will ya.

[1990C4S]

I will get photos tonight.

No rot. No bounce....

[dipso]

We had the same issue. The way we handled it, was to slope the last piece of tile.
Here are a few pictures.
2 of the bath entry and 2 of the kitchen entry.
The first of each set shows the entry view and the second shows the angle from the side. If you look at the casing, you can see how much they needed slope.

[dipso]

Oh I forgot to say how they did it. Our underlayment was level with the wood floor too.
What they did was use no underlayment where the tile would angle, that way the front tile edge matches the floor. Then build up the area underneath with cement so the back edge is level with the rest of the tile floor.

Seems to be holding up well. The bath is about 6 years old and the kitchen 1.

[trekkor]

Start with the original subfloor.

Install a long screw next to each nail. ( 2" or longer )

The hardie backer must be embedded in modified thin set with a 1/4x1/4 notched trowel or you will:

1. void the manufacturer's warranty.
2. likely get cracks in the tile
3. may hear pops or creaks in the floor when walked on.

I fasten the backer with 1.25" roofing nails. Tape the joints with fiberglass mesh using high quality thinset.

You may need to use a self leveling material to assure that the floor is very flat, given the type of tile you have selected.

With marble use a 1/2x1/2 or 3/4x3/4 notched trowel with a high quality thinset.
Take you time. Do not let the installation creep out of square.
Any lippage from adjoining tile to tile will look and feel awful ( especially on bare feet )

Pre-seal the marble with 511 Impregnator prior to grouting.
Use a stiff non-sanded grout and do not over wash or use excessive water in your sponges.
Do not attempt to remove all of the grout streaks, rather concentrate on a quality grout joint fullness and finish.

Re-apply a coat of sealer and buff dry.


Have fun~ Don't rush!
Marble or granite tiles are among the most difficult to install properly.


KT

[trekkor]

Use a transition strip that matches or compliments the floor of the surface adjoining the bathroom.


Let me know if I can be of any further assistance.


KT

[trekkor]

There are some good pics of the process in this thread:

Anatomy of a tile bathroom remodel


KT

[GH85Carrera]

Originally Posted by gr8fl4porsche

Can't help with the underlayment question but I just finished laying 12x12 marble.

Turned out great. No issues except some broken tiles due to the veining. Choose your cuts carefully based on veins which are the weak spots.

Highly recommend installing an electric mat heat system. Everyone in the house loves the warm floor.

+100 on the heated floor. We love ours and every guest that spends the night and walks on the guest bathroom floor in bare feet love it.

[1990C4S]

Originally Posted by GH85Carrera

+100 on the heated floor. We love ours and every guest that spends the night and walks on the guest bathroom floor in bare feet love it.

My bathroom will be heated. The room monkeys can wear slippers in their bathroom.

Actually for the small cost I expect I will add it. But not wire it until I sell the house....

[wdfifteen]

My recommendation:
You need 1/4 inch hardie board on the subfloor to keep the mortar under the tile moist while it sets. You want it to cure, not dry out and wood sucks the moisture out of it. Use thinset between the hardie board and the subfloor and screw the hardie down with 1 1/4" screws every 8 -12 inches (this may be a climate issue, around here we have a wide temp/humidity variance and really need to keep things tight). Marble is touchy because you have to be very careful setting it into the mortar to get it flush and level. It cracks more easily than porcelain so you can't pound on it as much. Have 4 foot and 2 foot levels and keep checking for level and flush. Take your time, mortar is cheap.

[Black968]

When installing a tile floor, you should have a minimum of 1 1/4" Plywood total measure. Also, make sure it is screwed down well (every 4 - 6"). I have done many tile floors and never had a problem using this rule. Any less, your grout joints will be constantly cracking from flexing. There is an unlayment you can use if you do not have plywood, but it is expensive.

[stealthn]

Use Ditra, it's what I am putting down in our basement bathroom we are just building along with the full Schluter shower system.

[JavaBrewer]

Originally Posted by trekkor

Start with the original subfloor.

Install a long screw next to each nail. ( 2" or longer )

The hardie backer must be embedded in modified thin set with a 1/4x1/4 notched trowel or you will:

1. void the manufacturer's warranty.
2. likely get cracks in the tile
3. may hear pops or creaks in the floor when walked on.

I fasten the backer with 1.25" roofing nails. Tape the joints with fiberglass mesh using high quality thinset.

You may need to use a self leveling material to assure that the floor is very flat, given the type of tile you have selected.

With marble use a 1/2x1/2 or 3/4x3/4 notched trowel with a high quality thinset.
Take you time. Do not let the installation creep out of square.
Any lippage from adjoining tile to tile will look and feel awful ( especially on bare feet )

Pre-seal the marble with 511 Impregnator prior to grouting.
Use a stiff non-sanded grout and do not over wash or use excessive water in your sponges.
Do not attempt to remove all of the grout streaks, rather concentrate on a quality grout joint fullness and finish.

Re-apply a coat of sealer and buff dry.


Have fun~ Don't rush!
Marble or granite tiles are among the most difficult to install properly.


KT

+1. Pro Advice here. Take it.

[1990C4S]

A few pics:












One more question: Should my vanity sit on the backer board? Or should I tile under it?

[peppy]

I just used a piece of redoak.
Before


After

[trekkor]

Using ONLY the method I described above gets my clients a lifetime guarantee.



KT

[look 171]

Yep. After seeing the pics, the floor looks great. Like Trek said, screw down the sub floor to the joists, glue the Hardibacker boards and nail /screw them down. Fill the void with the same thickness pplywood and screw it down.

toilet goes on the finish tile floor. Check the floor and don't forget the self leveling compound.

[1990C4S]

Originally Posted by trekkor

Start with the original subfloor.

Install a long screw next to each nail. ( 2" or longer )

The hardie backer must be embedded in modified thin set with a 1/4x1/4 notched trowel or you will:

1. void the manufacturer's warranty.
2. likely get cracks in the tile
3. may hear pops or creaks in the floor when walked on.

I fasten the backer with 1.25" roofing nails. Tape the joints with fiberglass mesh using high quality thinset.

You may need to use a self leveling material to assure that the floor is very flat, given the type of tile you have selected.

With marble use a 1/2x1/2 or 3/4x3/4 notched trowel with a high quality thinset.
Take you time. Do not let the installation creep out of square.
Any lippage from adjoining tile to tile will look and feel awful ( especially on bare feet )

Pre-seal the marble with 511 Impregnator prior to grouting.
Use a stiff non-sanded grout and do not over wash or use excessive water in your sponges.
Do not attempt to remove all of the grout streaks, rather concentrate on a quality grout joint fullness and finish.

Re-apply a coat of sealer and buff dry.


Have fun~ Don't rush!
Marble or granite tiles are among the most difficult to install properly.


KT

So I remove the plywood, screw the existing sub-floor to the studs, and put the Hardi board on the subfloor with thin-set?