kitchen floor cement board question
 

Hi, I am remodeling my kitchen and redoing my floor. I will be using
12x12 porcelain tiles. I want to know what needs to go under the
tiles.

The contractor have removed the existing vinyl flooring with some kind
of backerboard, this is what I have now:

http://fenjing.smugmug.com/gallery/4460346_n85dF

I was under the impression the contractor will put weather paper, then
a layer of cement backboard, and then the tiles..

My question is, can the cement backboard (1/4 or ??) go directly on
top of this? Or do I need another layer of plywood board (how thick)
beneath the cement board?

I asked my dad (who is somewhat knowledgable but by no means a pro),
he said the plywood board is essential because the cement board is
brittle if lying directly on the wood beams.

Can someone help me? The contractor just started yesterday so I
haven't talked to him about the flooring yet. He did mention weather
paper and cement board. Should I insist on ? cement board if he is no
plywood is involved?

Thanks!

Raymond

kitchen floor cement board question
 

There are many factors to consider, but what is that weather paper under the
cement board. The cement board should be bonded with thinset directly to the
floor under it with NO paper between. I would not install 1/4 cement board
over wood boards as you have, you need for 12 x 12 tiles, 1/2" cement board
over a layer of plywood, as thick as your installation will allow. The
plywood should be glued and nailed down to the floor boards and the cement
board thinsetted down to the plywood.

wrote in message
...

Hi, I am remodeling my kitchen and redoing my floor. I will be using
12x12 porcelain tiles. I want to know what needs to go under the
tiles.

The contractor have removed the existing vinyl flooring with some kind
of backerboard, this is what I have now:

http://fenjing.smugmug.com/gallery/4460346_n85dF

I was under the impression the contractor will put weather paper, then
a layer of cement backboard, and then the tiles..

My question is, can the cement backboard (1/4 or ??) go directly on
top of this? Or do I need another layer of plywood board (how thick)
beneath the cement board?

I asked my dad (who is somewhat knowledgable but by no means a pro),
he said the plywood board is essential because the cement board is
brittle if lying directly on the wood beams.

Can someone help me? The contractor just started yesterday so I
haven't talked to him about the flooring yet. He did mention weather
paper and cement board. Should I insist on ? cement board if he is no
plywood is involved?

Thanks!

Raymond

kitchen floor cement board question
 

What are we seeing in the pics? If that is the subfloor, and the
subfloor is on the floor joists, then you will need at least another
1/2" plywood plus 1/4" backerboard. You need at least a total of 1
1/4" solid flooring for the tiles not to flex or break.
That's what I did in my kitchen. I ripped up the floor down to the
3/4" subfloor, put 1/2" plywood, then 1/4" backer on top. Don't forget
you have to thinset the backerboard as well as screw it to the
plywood. I'm not sure why he would want to use weather paper. If that
is an existing oak floor in the pics, then he probably wants to use
the weather paper to prevent the oak from getting wet, which would
cause the oak to expand, thus cracking the tile

kitchen floor cement board question
 

So I talked to him, he said he'll use 1/4 hardy board. He said it's
like a cement board but the particles are finer. I asked him if he can
do 1/2 hardy (or cement) board and he insist those are used on walls
and not on floors.

He did not talk about a layer of plywood under the bardy board, and I
didn't ask him either since I am just reading this now. Is a 1/4"
hardyboard enough? How important is the plywood layer? He said there
will be another layer of cement (thinset) on top of the board so
having a 1/2" cement board is too tall.

Thanks!

Raymond

Mikepier wrote:

What are we seeing in the pics? If that is the subfloor, and the
subfloor is on the floor joists, then you will need at least another
1/2" plywood plus 1/4" backerboard. You need at least a total of 1
1/4" solid flooring for the tiles not to flex or break.
That's what I did in my kitchen. I ripped up the floor down to the
3/4" subfloor, put 1/2" plywood, then 1/4" backer on top. Don't forget
you have to thinset the backerboard as well as screw it to the
plywood. I'm not sure why he would want to use weather paper. If that
is an existing oak floor in the pics, then he probably wants to use
the weather paper to prevent the oak from getting wet, which would
cause the oak to expand, thus cracking the tile

kitchen floor cement board question
 

On Mar 5, 2:06 pm, wrote:
So I talked to him, he said he'll use 1/4 hardy board. He said it's
like a cement board but the particles are finer. I asked him if he can
do 1/2 hardy (or cement) board and he insist those are used on walls
and not on floors.

Yes. According to the instructions, 1/4 is stronger than 1/2.


He did not talk about a layer of plywood under the bardy board, and I
didn't ask him either since I am just reading this now. Is a 1/4"
hardyboard enough? How important is the plywood layer? He said there
will be another layer of cement (thinset) on top of the board so
having a 1/2" cement board is too tall.

The subfloor is the most important part of the job. The tiles will
crack if it's not right.

Like Mike said, 1 1/4" solid wood with any layers glued and screwed
together. Thinset and nails/screws securing the 1/4" hardiebacker.
And that's a minimum if the joists are solid.

And yes, all that makes for a high floor when all is done. There are
ways to deal with the transitions.

kitchen floor cement board question
 

The Reverend Natural Light wrote:

So I talked to him, he said he'll use 1/4 hardy board. He said it's
like a cement board but the particles are finer. I asked him if he can
do 1/2 hardy (or cement) board and he insist those are used on walls
and not on floors.

Yes. According to the instructions, 1/4 is stronger than 1/2.

He did not talk about a layer of plywood under the bardy board, and I
didn't ask him either since I am just reading this now. Is a 1/4"
hardyboard enough? How important is the plywood layer? He said there
will be another layer of cement (thinset) on top of the board so
having a 1/2" cement board is too tall.

The subfloor is the most important part of the job. The tiles will
crack if it's not right.

Like Mike said, 1 1/4" solid wood with any layers glued and screwed
together. Thinset and nails/screws securing the 1/4" hardiebacker.
And that's a minimum if the joists are solid.

The contractor insist that a plywood layer is not suitable for my
case. He said when he does new constructions he uses 3/4" plywood
because the sub-floor is not as strong as older homes so the plywood
is needed for structural needs. The wood subfloor you see in the
pictures are pretty thick and these types of homes don't need a layer
of plywood (mine was built in 1960). On the adjacent rooms where there
was hardwood floor, the hardwood sits directly on top of the subfloor,
there were no plywood in between... but hardwood is probably
differentn from hardyboard and can flex somewhat.

ah crap.

Raymond

kitchen floor cement board question
 

The contractor insist that a plywood layer is not suitable for my
case. He said when he does new constructions he uses 3/4" plywood
because the sub-floor is not as strong as older homes so the plywood
is needed for structural needs. The wood subfloor you see in the
pictures are pretty thick and these types of homes don't need a layer
of plywood (mine was built in 1960). On the adjacent rooms where there
was hardwood floor, the hardwood sits directly on top of the subfloor,
there were no plywood in between... but hardwood is probably
differentn from hardyboard and can flex somewhat.

ah crap.

Raymond

How thick is the subfloor in your picture? Most subfloors are 3/4".
Hardwood flooring is usually put right on top of the subfloor, there
is no plywood underneath.

kitchen floor cement board question
 

"Abe" wrote in message
...

"Abe" wrote in message
.. .

So I talked to him, he said he'll use 1/4 hardy board. He said it's
like a cement board but the particles are finer. I asked him if he can
do 1/2 hardy (or cement) board and he insist those are used on walls
and not on floors.

He did not talk about a layer of plywood under the bardy board, and I
didn't ask him either since I am just reading this now. Is a 1/4"
hardyboard enough? How important is the plywood layer? He said there
will be another layer of cement (thinset) on top of the board so
having a 1/2" cement board is too tall.

No, the hardyboard alone is not enough. You need 3/4" structural
plywood with a sanded face underneath it. A vapor barrier should go
between the subfloor (shown in your pictures) and the plywood. The
plywood should be screwed down or nailed down with ring shank nails
every 8 inches in all directions. The hardy board 3/8" or prefereably,
1/2", not 1/4", is then screwed to the plywood (nails are not used
here). Then the tile is set with the proper setting material on top of
the hardy board.

You left out a decoupling membrane ;)
How can you know what he needs if you dont know the joist spacing?

I'm assuming standard 24" O.C. joists. You're right, I shouldn't
assume.

Thanks. Thats explains why I thought most of the floor advice I saw was way
thicker than needed. My joists are 18".

kitchen floor cement board question
 

On Mar 6, 3:37*am, Mikepier wrote:
The contractor insist that a plywood layer is not suitable for my
case. He said when he does new constructions he uses 3/4" plywood
because the sub-floor is not as strong as older homes so the plywood
is needed for structural needs. The wood subfloor you see in the
pictures are pretty thick and these types of homes don't need a layer
of plywood (mine was built in 1960). On the adjacent rooms where there

How thick is the subfloor in your picture? Most subfloors are 3/4".
Hardwood flooring is usually put right on top of the subfloor, there
is no plywood underneath.

It looks like 2x6 cardeck which would be very solid 1/4 inch hardy
right over the top.

kitchen floor cement board question
 

d wrote:

The contractor insist that a plywood layer is not suitable for my
case. He said when he does new constructions he uses 3/4" plywood
because the sub-floor is not as strong as older homes so the plywood
is needed for structural needs. The wood subfloor you see in the
pictures are pretty thick and these types of homes don't need a layer
of plywood (mine was built in 1960). On the adjacent rooms where there

How thick is the subfloor in your picture? Most subfloors are 3/4".
Hardwood flooring is usually put right on top of the subfloor, there
is no plywood underneath.

It looks like 2x6 cardeck which would be very solid 1/4 inch hardy
right over the top.

The subfloor is about 1.5" thick. This is how thick the subfloor is on
the cover to the craw space (on top of the 1.5" is the actual hardwood
floor on the cover).

Now my neighbor told me that the kitchen subfloor has been replaced
before due to termite damage, so it may not be as thick as the rest of
the house..

It's all done now. Subfloor + 1/4" hardyback + thinset + US made 13"
porcelean tile. It feels fine. The cabinets, frig, stove and
everything else is in, and the tiles didn't crack during the install.

With just the 1/4" hardyback installed, I walked on it and it feels
soft. I was quite upset thinking that it won't be enough. But after
the thinset and tiles are layed down, it feels much better now.

I didn't know the subfloor were not the original ones when I started
the job, had I know that, I would've insisted on either 1/2 hardyback
or a layer of plywood. Oh well. I am pretty careful anyway and walking
on it wearing slipper it feels pretty sturdy, for now. ;)

Thanks everyone!

Raymond

kitchen floor cement board question
 

The subfloor is about 1.5" thick. This is how thick the subfloor is on
the cover to the craw space (on top of the 1.5" is the actual hardwood
floor on the cover).

I didn't know the subfloor were not the original ones when I started
the job, had I know that, I would've insisted on either 1/2 hardyback
or a layer of plywood.

No need for the additional ply- what you have is definetly 2x6 if it's
really 1.5inch. Good solid floor. Don't worry about it- it'll
outlast you!