Some of you may remember that I posted a question here about tiling over
an existing laminate counter. Well, it's done, and I wanted to report
back here in case it might be useful for anyone with similar questions.

The customer (a friend, actually) wanted new tile counters. The existing
counters were 60s or 70s-style Formica, complete w/rolled lip, over
particle board. After removing the counters, the plan was to either put
plywood over the laminate, and Wonderboard over the ply, or, as we
realized would be possible after starting to strip the counters, put
Wonderboard directly over the particle board.

I say "after starting to strip the counters", as we did start to rip the
Formica off the countertop: this, however, turned out to be such a
massive pain in the ass that we quickly abandoned the idea. Would have
taken many hours to accomplish this. Then I posted my question here, and
also did some searching on the Web.

What we discovered was that you can actually put Wonderboard directly
over Formica. This was something I wouldn't have believed either, but
after a trip to a local tile store with a good reputation, this was
confirmed.

The trick is to use the mortar that we already had bought, which was
polymer-modified (*not* latex-modified), which will basically stick to
anything (well, not sure about glass, but just about anything else).
Just to be sure, we scuffed up the Formica with coarse sandpaper.

Everything went on smoothly; the counter is now in use, and shows no
signs of weakness.


--
Just as McDonald's is where you go when you're hungry but don't really
care about the quality of your food, Wikipedia is where you go when
you're curious but don't really care about the quality of your knowledge.

- Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm)

David good post thank you. I'm considering doing the same thing and
have some questions you may be able to answer. Did you consider
screwing wonderboard directly in laminate counter?
As opposed to using a motar. Also what thickness was the wonderboard -
did you use - 1/4" or 1/2". Did you consider using hardibacker. Finally
how thick was the laminate countertop to begin with? Thanks in advance.

Hmm... might like to do the same ...

How did you deal with the raised edges around the sink?

Did those rolled edges also have a hump? If so how did you deal with
that?

I say "after starting to strip the counters", as we did start to rip the
Formica off the countertop: this, however, turned out to be such a
massive pain in the ass that we quickly abandoned the idea. Would have
taken many hours to accomplish this.

Not a surprise.

The trick is to use the mortar that we already had bought, which was
polymer-modified (*not* latex-modified), which will basically stick to
anything (well, not sure about glass, but just about anything else).
Just to be sure, we scuffed up the Formica with coarse sandpaper.

Why not use self-drilling cement board screws?

TIA for your reply...

spake thus:

David good post thank you. I'm considering doing the same thing and
have some questions you may be able to answer. Did you consider
screwing wonderboard directly in laminate counter?
As opposed to using a motar. Also what thickness was the wonderboard -
did you use - 1/4" or 1/2". Did you consider using hardibacker. Finally
how thick was the laminate countertop to begin with? Thanks in advance.

1. I did use some drywall screws to secure it (in addition to thinset),
but just a few, a couple in the center and one or two along each edge,
just to keep it from sliding before it set.

If you screw it, you should still use mortar.

2. 1/2". Considered Hardibacker, but I've used Wonderboard before, and
it seemed just as good and a little cheaper.

Actually, one section was 1/4", since part of the countertop was a
marble slab that was thicker than the tile. We didn't quite match the
levels--the marble sits proud of the tile--but it's close. Just mortared
the marble over the Wonderboard.

3. The laminate was the usual approx. 1/16" or so; the underlayment was
3/4" particle board.


--
Just as McDonald's is where you go when you're hungry but don't really
care about the quality of your food, Wikipedia is where you go when
you're curious but don't really care about the quality of your knowledge.

- Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm)

spake thus:

How did you deal with the raised edges around the sink?

Did those rolled edges also have a hump? If so how did you deal with
that?

Ah, yes, the rolled edges; should have said a word about those.

What we did was to score the laminate about 1-1/2" back from the edge
with a utility knife, then strip it off. (It came off pretty easily.)
This left a particle-board hump, actually a separate piece from the
counter. I just ran a hand plane (my 9" Stanley jack plane) over the
hump and made it disappear. Ended up with a nice flat front edge.

The trick is to use the mortar that we already had bought, which was
polymer-modified (*not* latex-modified), which will basically stick to
anything (well, not sure about glass, but just about anything else).
Just to be sure, we scuffed up the Formica with coarse sandpaper.

Why not use self-drilling cement board screws?

Those would work too. As it was, the screws weren't really holding
anything together, just locating the underlayment until the mortar set.


--
Just as McDonald's is where you go when you're hungry but don't really
care about the quality of your food, Wikipedia is where you go when
you're curious but don't really care about the quality of your knowledge.

- Matthew White's WikiWatch (http://users.erols.com/mwhite28/wikiwoo.htm)