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Old 02-18-2010, 09:18 PM   #16
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Yea, I was waiting for Bud to answer and I agree of course.

It isn't clear to me what you have there. You need to get down to the subfloor, which is the wood that is directly above the joists. You said something about old oak flooring underneath. Please describe every layer.

In any case, I'm sure you will need a sheet of plywood underlayment then your Hardie and then the easy part, the tiles. Answer Bud's joists questions too.

Jaz

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Old 02-18-2010, 10:40 PM   #17
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Quote:
Originally Posted by JazMan View Post
You need to get down to the subfloor, which is the wood that is directly above the joists.
That is the correct way, and it will give you proper transitions between rooms.
I didn't realize before that you aren't pulling the cabinetry.
This will make your job harder because that layer of flooring that you just exposed probably runs under the cabinets, but a circular saw won't fit under the cabinet toe kick.
You could rent a toe kick saw:
http://toolmonger.com/wp-content/upl...oe_Kick_TM.jpg
You can try to hack it away with a reciprocating saw, but if it is oak, then you're in for a battle.
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Old 02-18-2010, 10:47 PM   #18
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Just for anyone lurking.....

THAT "toe-kick saw" is one of the most dangerous tools known to mankind. BE CAREFUL when using those things, they aren't for the backward or wimpy.
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Old 02-18-2010, 11:28 PM   #19
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lay down some hardibacker concrete backerboard. Screw this down so you dont get floor squeaks

Tile over the top of this
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Old 02-19-2010, 05:43 AM   #20
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Bud,
Not sure what you mean by "free span"?
Floor joists are 1 1/2 x 9"
Set 16" apart
Pic is taken in basement directly below kitchen floor.

Jaz,
After further inspection, floor only has one layer of 5/8's plywood as shown in pics above.

As dairylander pointed out I did not plan to remove the cabinets.

What is the advantage of ripping the old plywood out if I'm going to turn around and lay new plywood down?

As always, Thank you for your advise.
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Last edited by Stcrosby; 02-19-2010 at 06:03 AM. Reason: added info
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Old 02-19-2010, 08:30 AM   #21
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What is the advantage of ripping the old plywood out if I'm going to turn around and lay new plywood down?
Around these parts, most people put backer board directly on the primary sub-floor (the diagonal 1x6s).
An intermediate layer of plywood will reduce flex, even out inconsistencies and be more stable than solid lumber.
However, you have a small room and with 2x10 joists that are 16" on center, the plywood might be overkill.
If it were my house, I'd pull the plywood, lay a heavy backerboard over the sub-floor, then tile.
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Old 02-19-2010, 08:44 AM   #22
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Originally Posted by Stcrosby View Post
Bud,
Not sure what you mean by "free span"?
What distance are the joists spanning?
If they go from cement foundation wall to cement foundation wall, then measure this distance.
If they have a cross beam or support post under them somewhere, then measure from there to the cement wall.
This distance helps figure how rigid the structure is, how much weight it can hold, and if it needs that intermediate layer of plywood.
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Old 02-20-2010, 03:35 PM   #23
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Recommending the use of any cement board tile underlayment over a "slat" subfloor is bad advice. You won't find that suggestion in any of the legitimate industry how-to recommendations. Here's the issues with that procedure and why it is never a good idea.

Those boards, be-they 1 X 4, or 1 X 6, or 1 X 8, or 1 X whatever, are solid wood. They will routinely expand and contract with temperature change and environmental moisture fluctuations. They can move in all directions. These boards will also routinely "cup" or "crown" based on the run of their grain and where they have been cut from the primary log. This is all natural phenomenon and occurs in all wood.

Cement board has no structural value and can't possibly (by itself) contain any of this type of movement. To make matters worse...cement boards whether they are standard cement or fiber cement, mesh-laden or not, will move at a different rate then wood. Cement boards are vulnerable to movements originating in the substrate they are attached to.

Plywood, on the other hand, still a wood product and still subject to some expansion and contraction, is constructed in a manner that places directional forces within the wood layers in opposition to other layers within the wood layers that make up the plywood panel, thereby stabilizing movement.

A layer of plywood between a "strip-wood" subfloor and a layer of cement board is in my opinion, mandatory.

It doesn't matter what "everyone in any area" is doing. What matters is understanding why the recommendations are what they are and in wanting to abide by some discipline created through research that is recommended for some reason.

Ceramic and stone tile installations on the other hand are typically a very rigid and unforgiving entity. Movement is an enemy of a tile installation. Instability in a sub-structure under a rigid tile installation is an enemy to the tile installation.

Manufacturers have spent billions of dollars on research and development of the products you find on the market today that will help to isolate and separate a tile installation from an incompatible substrate. Just recently Laticrete International has introduced a new thinset containing rubber and even Lexan. These guys wouldn't be doing this if it wasn't necessary.

I hope this helps to explain to everyone the potential damage that could result from recommendations to proceed otherwise. Do it correctly following industry recommendations and you'll only do it once.
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Old 02-21-2010, 10:44 AM   #24
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Bud,
A well explained and detailed suggestion such as yours helps the new guy tremendously.

Dairy, thanks for your explanation and interest as well.

I have decided to lay 5/8s plywood down and then 1/4 backer board.
I was advised to apply a conservative amount of thin set under the backer board and then use dura roc screws(approx 12 per 3x5 sheet) to affix to plywood.

Then I'll begin tiling.
Thx again to everyone
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Old 02-21-2010, 02:29 PM   #25
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Quote:
I was advised to apply a conservative amount of thin set under the backer board and then use dura roc screws(approx 12 per 3x5 sheet) to affix to plywood.
I'm not sure what is meant by "a conservative amount of thinset" but the truth is the boards should be installed into a bed of thinset that covers 100% of the board. The cement board makers website will have the proper installation recommendations. That's where the "I was told" information should be coming from. They have a particular trowel in mind to be used to spread the thinset. Check it out.

Twelve screws isn't going to get it either. I have no idea where you are getting your information but my suggestion is you get it from a different source. Try researching and using the cement board manufacturer's recommendations. The requirement for the screws is to place them at every 8" in both directions and maybe a little closer around the perimeter. That is going to add up to about 48 screws per board NOT 12.
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Old 02-21-2010, 08:26 PM   #26
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Will do. Found additional info here.
http://www.usg.com/rc/installation-a...e-en-CB237.pdf

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