Can anyone tell me the proper adhesive to secure ceramic tile
underlayment (hardiboard or duroc) to advantech subfloor? I know this
is done all the time so I assume there is a typical method. Thinset
mortar is not recommended for particle board which advantech is.
Someone told me liquid nails is what I should use....?
Thanks in advance,
Not quite true. The prime enemy of tile is substrate movement.
Thinset supports the entire backer board, not just a few spots like
construction adhesive. If your subfloor is dead flat and you've dealt
with lippage between adjoining sheets by sanding or using a feathering
compound, the thinset is probably not necessary. I still use it every
time as it's foolproof and takes care of a lot of issues in one step.
Bonding layers together provides a far stiffer assembly than screws
and a bit of glue.
This from USG's web site:
Laminate 12.7 mm (1/2)
DUROCK Panel to minimum
16 mm (5/8) thick exterior
grade plywood using adhesive
or mortar suitable for bonding
cement backer board to
plywood.Apply adhesive with
16 mm (5/8) V-notched
trowel or mortar with 6 mm
(1/4) square-notched trowel.
Laminate and secure one
panel at a time.Cover the
adhesive with the board
First of all, I would seal the particle board with a product
like RedGard or equivalent.
That will help to protect it from the inevitable moisture
damage. That done, I would not use liquid nails, but a
product like PL400, which is self shimming.
What that means is that if there are variations in floor
heighth (an uneven floor), the PL400 will fill AND SUPPORT the
gaps between the particle board and the hardibacker. This
reduces flex which is the enemy of tile installations.
In addition, I would use screws to mechanically fasten the
hardibacker. The PL400 will help to bridge depressions and
bond the substrates together and the screws will pull the two
surfaces together tightly. The entire system serves to
Finally another application of Red Guard over the seams to
eliminate as much water intrusion onto the particle board as
The best possible application would be to replace the particle
board with plywood, but you did not ask that question. Also,
make sure that you have at least 1-1/4" of support under the tile.
On Aug 11, 1:47 pm, firstname.lastname@example.org wrote:
Advantech is billed as being water resistant, though not for long term
exposure. I seriously doubt you'd have a problem with directly
attaching the backer board with thinset or mastic. If you're
concerned, you could seal the Advantech before using the thinset, and/
or you could use an alternative system such as Schluter's Ditra.
http://www.johnbridge.com/ceramic_tile_floors_ditra.htm It's a bit
more expensive, but it's waterproof, serves as an uncoupling membrane
(no cracks) and it's easy to install.
Check out the John Bridge tile forums - excellent tiling resource.
replying to RicodJour, Jtmax88 wrote:
I am installing a ditra system over advantech on an outside deck that will be
tiled. The contractor has painted over the advantech. Do I have to sand that off
before I can install my ditra over that advantech. I know that conventionally
you can not apply anything to a painted surface.
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