On Oct 25, 12:35 pm, Mikepier wrote:
On Oct 25, 10:03 am, Manster wrote:



samurai wrote:
On Wed, 24 Oct 2007 09:38:16 -0700, Manster wrote:

Mikepier wrote:
A few weeks ago I asked if I could tile over oak floor area in my
foyer 4'X15' and everyone suggested using some kind of underlayment.
Recently my wife and I picked out a tile that is 1/2" thick and is 11
3/4" X 11 3/4". This tile looks a lot more beefy than ordinary tiles
and of course costs twice as much. Now the problem is because it's
1/2" thick it would be a problem heightwise even if I used a 1/4"
backerboard. So my question is will this tile be less likely to have
problems if I go over the wood floor because it's so thick even if I
screwed down the floor at every joist.
By the way my combined subfloor and hardwood thickness is 1 1/2".

An 1-1/2 is a pretty thick sub-floor already without adding a 1/4"
board. If the oak floor is roughed up a bit and the joists are not
spaced too far apart and there's no flexing between them, you should be
fine. Someone mentioned sealing the sub-floor first, but I disagree. A
sealer may interfere with the adhesive you use for the tile.

I would be hesitant to put over oak floor, as it may let loose or
float(due to heat and humidity), and result in cracked grout. Oak
floors are just nailed in, and will 'creak' over time. Ever had a
squeeky wood floor?? Especially in a high traffic area, you want it
strong as possible.

To do it properly, remove the oak, then you'll have laths which are
over the floor joists. Put 1/4 plywood, then a thinset, then 1/4"
Wonderboard (or whatever to meet the desired other flooring height),
then mortar and tile. Be sure to use screws to secure the Wonderboard
throught to the joists.

You could even remove the laths, then you could nearly match your
existing flooring. You'd need minimum 1/2" plywood, and 1/2"
Wonderboard.

That would be a rock solid finish.

samurai.

The OP said he was screwing the oak to the joists. Anyway, a 1/4"
Hardibacker over the oak would give it some density, however ripping it
out is overkill and 1/4" plywood is good for cabinet backs, not
sub-flooring. Also the Hardi or Wonderboard does not need to be screwed
to the joists. Ya want proper? Place an actual mortar bed over the
sub-floor for a tile base.- Hide quoted text -

- Show quoted text -

What if I used an anti-crack membrane over the oak floor?

See my post. That's exactly what I did over a maple floor.

JK