Replies

1. 
   Guest_ | Aug 24, 1999 07:25pm | #1

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   Bill;

   The success of a tile job depends a lot on what is underneath it. If you can answer "yes" to all of these questions, then go ahead.

   Is the existing countertop sound and rigid (REALLY RIGID), no flexing where it bridges over empty spaces like above dishwasher?

   Is the formica stuck down tightly? No gaps, no letting go?

   Can you live with the added counter height? If the kitchen will be used by someone under 5'2" anything over 36 inches might be uncomfortable.

   Do you have a plan for the backsplash? If it's a molded-in formica backsplash this could be tricky. If it's a separate piece, the joint might not be tight and rigid. The top edge might be a challenge.

   Do you have a plan for the front edge? The total thickness of the finished countertop could make it look kinda clunky.

   Depending on how your kitchen is constructed, it might be difficult to remove the old countertop without causing too much collateral damage. Maybe a half-way solution would be to leave the countertop in place (if it passes the rigidity test), but try to peel off the old formica.

   You'll want to make sure the cement board adheres well to the formica, if it is going to stay. Maybe the thing to do is go over the formica with a coarse belt sander. I would be leery of using mastic or construction adhesive to stick the cement board to the roughened formica, because in my experience most mastic stays a bit rubbery for a long time, and that little bit of "give" could lead to grout cracking when you drop that 20-lb frozen turkey on it next Thanksgiving. Probably thinset mortar with an additive would be best for setting the cement board solidly.

   I'm just a DIY amateur, but I've done a few floors and countertops. I just finished a pretty large kitchen countertop, using two layers of 3/4 ACX plywood glued together for a rigid substrate, and for the first time used hardiboard instead of cement board (based on recommendation from a professional tile-setter) and in our situation the 1/4 thickness was better than 1/2 inch. Hardiboard was easier to cut (best to score it on both sides before snapping it), and it didn't crumble around the edges but I found it impossible to put it down with screws. The material is so hard that the screws couldn't pull themselves down flush with the surface, and I wasn't about to drill and countersink a million screw holes. I ended up using ring-shank nails. Galvanized roofers might have worked too.

   Hope your project works out ok.

   Jay

1. 
   Guest_ | Aug 24, 1999 09:50pm | #3

   *Lots of good advice! I'm going to try to salvage the sink area of a laminate countertop so I can reuse the 3/4" ply and sink cutout, saving time & material. The laminate is a good waterproofing layer to boot.Bill, you might be able to whack off the pieces scabbed under the counter to take it from 3/4" to 1 1/2" so that the finished counter thickness will come out OK. Alternatively, a new 3/4" ply substrate would be pretty easy to put together. Michael Byrne's book (from Taunton) has some good advice on kitchen counters.

2. 
   Bill_Burton | Aug 24, 1999 09:50pm | #2

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   I just read the article on "Tiling a kitchen counter" by Dennis Hourany in issue #120. I have a question that someone may be able to answer. My existing counter is formica. I had intended to completely remove the old counter top. Then use 3/4" exterior plywood, cement board and then ceramic tile. Someone had suggested that I could leave the existing counter top, put cement board over the formica then the new ceramic tile. Can I do this?