I've read that the boards should be cut so they line up with the joists
underneath the subfloor (similar to hanging drywall). I've also read that
the minimum subfloor should be 5/8" of plywood, and that 1 1/4" screws
should be used (also similar to drywall). The difference is that drywall is
attached directly to studs, whereas with the backerboard, those screws won't
make it through the 1/2" of backerboard plus 5/8" of floor (yes, 1/4" past,
but not enough to justify screwing over joists.) Comments?
that is correct
all joints should end 1/2 way on joists
otherwise there would be to much deflection where the backerboards meet
causing it to crack.
that would depend on the floor joist spacing.
1 1/4" screws are usually recommended so you will not screw into a pipe or
wire by accident.
backerboard does NOT need to be fastened to the joists.
the subfloor is fastened to the joists.
the backerboard is fastened to the subfloor.
the finished tile is fastened to the backerboard.
personally I would rather install 1/2" backer board with thinset instead of
maybe a few 1 3/4" galvanized roofing nails (nailed into joists) to hold it
in place until the thinset is dry.
you are misguided there AnnG
ALL sub flooring
cementious or wood should always end on a joists whenever possible.
besides it is "good practice"
I have probably installed over 3000 sheets or durrock over the years.
screws......you obviously have never installed durrock.
they are the worst fasteners for installation.
they just want you to purchase "their special screws"
galv. roofing nails I must admit are the BEST.
but the thinset helps bond the backerboard to the substrate better.
mastic for a floor..........OMG
never,never,never use mastic on a floor for anything.
it is made for walls and ceilings ONLY.
(as you put it)
READ THE MFR'S INSTRUCTIONS
how much tiling have you done?
So? That doesn't make you correct. That only speaks to you either not
knowing the superiority of mortar for substrates or you have no decent
tile artisans in yoru area. Either way they are a substitute at best
Like I said, read the mfger's instructions.
I've never used screws for backerboard. Nails only. And btw, mastic
serves the same purpose as the thinset for underlayments over plywood.
30 years or so. 4 crews doing primarily 500k+ homes and commercial
floors. All counters, tub and shower walls are set over mortar. When
certain job conditions dictate, tile backerboard is substitued for
mortar on wood subfloors.
While tile underlayments are useful for wood subflooring tile substrates
when elevation factors, etc, come into play; for the most part they are
for use by happy homeowners and architects with no practical experience
in the real world of professional tile setting.
3,000 sheets eh? And bragging??? I would stack my experience and
quality up against yours any day of the week..
I've no doubt you and I would get along great irl. I'm all for doing so
here too. No offense meant and my appologies to you if it seemed so.
Hey were you ever around the Haight Ashbury scene in the 60's?
1/4" hardibacker is denser than the standard 1/2" 'other stuff' and
eliminates elevation problems in many cases. Install it with either
tile masti or thinsret and 1-1/4" galv. roofing nails. The joints do
not need to land on a joist, however you're subfloor must be constructed
properly, with all code specified material sizes, spans, etc, in place.
Generally I would not advise a tile backerboard over 5/8" ply as a tile
substrate. Perhaps another layer of 1/2" CDX followed by the 1/4"
hardi, but it depends upon your subfloor construction as I pointed out
You might consider having a pro float a mortar bed substrate for you.
1/4" galvanized roofing nails and hardibacker. I thought I would do it
right and use screws. Even with the best auto-countersinking screws for
backerboard, I could not get them driven into the hardibacker without
drilling pilot holes and countersinking ahead. I went and bought the nails.
With a nail every six inches in every direction that stuff is not going
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