Flooring Tile - tiling over laminate countertop?

our countertop is u-shaped, custom-built, particle board covered with laminate. it is probably 30 years old. the particle board looks in excellant condition. there are a couple spots where the laminate is comming up. the countertop is locked in by the backsplashes that are probably glued to the drywall. i'm not sure how to get those backsplashes off, especially without having major repair work done to the walls. so, i'm leaning toward tiling the laminate. using a backerboard would buildup the countertop, reducing clearance between the upper cabinets and coutertop. so i'd rather not use the backerboard. my question is, if were to strip the laminate off the countertop is it possible to tile the particle board. or is it better to sand and tile the laminate?

Once you mentioned the laminate is coming up in some areas, you've pretty much ruled out scuffing and tiling the counter top. Particle board cannot be used as a substrate for tile and very likely would swell just from the moisture in the thinset. Your best bet is to remove your sink and cooktop if you have one, then unscrew your countertops from underneath and remove them. Then build a new countertop out of 3/4" bc or better exterior grade ply with a layer of 1/2" cement board, etc, etc. First remove the backsplash. If it's glued to the wall, a pry bar will do the trick. If it's part of the counter top, it will just come off with the countertop. The minimal damage you cause can be covered with a new tile backspalsh, but there will be damage to the sheetrock and not much you can do about that. Install the plywood tothe counter tops leaving a 1/8" gap at the walls. Caulk this joint before proceeding. Make you sink cut out with a jig saw and cook top cut out. Lay your 1/2" baker board, already cut to width over your ply and from underneath your plywood, mark the cutouts for your sink and cooktop You also want to have a 1/8" gap at the wall and between sheets of backer as you dry lay it for the cutout locations. Make your cut outs with a carbide blade in a jigsaw out side, and from the paint dept at a big bos or hardware store, buy a dustmask rated N-95 or better as the dust from mechanical cutting of cement boards is quite hazardous. Silica, you know. Any way, come back in and set your cement board in unmodified thinset spread over the plywood using a 1/4"x1/4" square notch trowel and screw it down using 1 1/4" backer screws every 6" over the face of the board. My preference for backer screws is "backer on" because they use a square drive bit which reduces the chances of heads stripping out and set better, but if they don't have them where you shop, it's not a bad idea to hit each screw location with a counter sink bit so you don't have all your screw heads sitting proud. Then set your tile using modified thinset laeving 1/8" at the back for a caulk line. It may sound like alot of work, but is sure is alot less than removing the laminate and getting off the old adhesive only to find out after setting your tile how problematic particle board is under tile. It will actually take the same amount of time or less than the time and effort it will require to get the particle board claened up. Cement boards will absorb water and removing the laminate and installing cement boards will cause all the same problems as well.

then why not just use a backerboard over existing? and just screw it on?

Once the laminate is coming up, you can count on moisture problems existing in the particle board. It is the swelling whether you can see it or not at this point that probably caused the bonding to fail in the first place. This will continue to occur, weather you put cement board over top or not and the cracking/chipping caused by screwing/nailing through the laminate will allow more points of entry for moisture. Cement board is does not waterproof and any water that penetrates the grout will soak down into these spots. It is also more problematic when you try to cap the edges of the coutertop with your cement board where the swelling occurs, and if you have a rolled drip egde, you wont be able to level your tile. Best to start from scratch with the proper substrate. It would cost me more not to do so than for a homeowner doing a diy job as responsibility would fall on me, and I cannot responsibly give advice that I know has the potential for failure.

I will add my $.02 even though nobody asked and tilebri is giving good advive. I will come from the point of view[right or wrong] that people come here to do a job by themselves and save major money in the process.


This project sounds like it can be handled in a few ways. The best way is to rip it out and start fresh.Another way is to add 1/4"hardibacker to the laminate and then tile. My choice [since I am the homeowner] would be as follows. First I would not assume that the delamination of the formica was a moisture problem. Maybe they was a lack of adhesive or something,who knows. Remove the sink. Then I would get a small router and set it to the depth of the thickness of the formica and rout out the pieces that are delaminating.Dry the area with a hair dryer if necessary. Then I would spray it with a few coats epoxy primer and fill with bondo. Leaving the bondo below the surface of the remaining laminate. When dry I would clean, scuff sand, and tile.

Again this is what I would do if it were my kitchen. If the tile is set right and the grouting is done properly and sealed I see little chance that moisture will cause a problem.

I am also assuming that there is relatively little delamination occurring.Maybe the edges a little and a littlle in a corner. Removing formica that has been properly glued is not a project I would consider doing.

thanx guys. the laminate is coming up only around one seam, away from the sink or any moisture area, and is only about 12 inches in length. i agree that if you want the countertop to last a hundred years, start from scratch, but if i could get another 15 or 20 years, i'd consider using yhe existing substrate.