Flooring Tile - Tiling a kitchen with conventional foundation

I am about to tile my kitchen floor. It currently has linoleum on a wooden subfloor, with a conventional foundation. I have asked a couple of people about what additional subflooring material do I need to install, if any, but the people that I have asked have been fairly non-committal.

So, my question is, how can I tell?

How much (thickness) subfloor is necessary for tile? Does the thickness of Backerboard count towards this? If I need to add additional plywood flooring before adding the backerboard, can I just screw that into the subfloor as it currently exists and leave the linoleum, or do I definitely need to pull the linoleum up? Is adding 1/2" backerboard strong enough?

Also, I think we're going to do a total remodel, so would you all suggest pulling cabinets up before-hand?

What other information did I leave out that could help you all help me?

Thank you very much for any help!!!

Lou

Lou,

The bare minimum would be 3/4" Tongue and Groove plywood over joists set at 16" on center, and that is for ceramic tile. The size of the joists and the length of their unsupported span are equally important as the wrong size joist or one that stretches too far under the weight it has to support, will sag and the amount of sag may be greater than the tile will tolerate. Post those number and someone will run them to check for floor acceptability.

The vinyl should come up, in fact has to come up if it is cushioned or has 1/4" luan under it. You can cut the vinyl/luan into 2' squares with a circular saw, the blade depth set so it just cuts through the bottom of the luan. Lift the squares with a long prybar and pull the staples left behind or hammer them flush to the floor.

The cement board should be used but does not offer structural strength, just a much better coupling for the thinset. An additional 1/2" sheet of BC plywood over the 3/4" would help the integrity of the tile install.

Pulling the cabinets and setting tile would be better in my opinion, seals the floor from a cavity opening under the cabinets and dishwasher and puts all appliances on the same plane with the cabinets.

Ok. I got under the house yesterday. Here is some more information, from what I could see. Also, I removed the stove and there was no linoleum under there, so I could see plywood from the top. From underneath, there were 3/4 in planks, running diagonally across the floor joists. The joists were 2x8 boards, running 10 ft betweeen 2x10 beams. The 2x8's had blocking running halfway in between the beams.

From underneath, where there were small gaps between the subfloor boards, I didn't see the plywood that I was able to see from above. Instead, I saw something that was black laying over the top of the boards. Was that some type of black moisture barrier in between the subfloor and the plywood? Is the plywood that I am seeing from the top the "luan" that you mentioned? If not, what is 'luan'?

Does any of this help? Thank you again for any suggestions!!! I am hoping to get a firm grip on everything before I get started ripping things out!

Thanks, TileGuyBob for the suggestions!

Can I just screw 1/2" plywood to the floor as it now lays? Is it imperitave that I remove the linoleum? Is there any danger of asbestos in the linoleum or it's adhesive?

Also, I just realized that I forgot to mention in the earlier post that the floor joists are spaced 16" centers.
Thanks for any thoughts or suggestions!!!

You need to remove the linoleum and any 1/4" plywood or particle board underlayment. Add 1/2" of exterior plywood bc or better. If height is a concern you could use a membrane like ditra or cis instead of backerboard. Your floor joists are fine for ceramic tile. REMOVE THE LINOLEUM.

Thanks, HeresJohnny.

Do I need to remove whatever is underneath the plywood (the black material that I was able to see from underneath)?

Do I need to put any type of barrier or anything in between the new 1/2" exterior plywood and the existing 3/4" planks?

Also, do I just assume that the plywood is 1/4"? What if it's really 1/2"? If that's the case, can I just remove the linoleum?

Is there any danger of removing the linoleum and disturbing asbestos or anything?

Thank you all again for any suggestions!!!

I want to make sure that I understand exactly what you currently have. Is this right. 3/4" planking, "black material" plywood (dont know how thick) and then linoleum?

Is there a floor register where you can check the thickness of the plywood? If not drill a test hole in a corner and see how thick the plywood is. If its 1/2" or more you probably ok but usually thats not the case. The black material between the planking and the plywood is probably builders felt. If thats the case and the plywood is 1/2" it can stay there.

If the plywood underlayment is 1/4" it has to come out with the linoleum. In any case the linoleum has to go. Yes the linoleum can possibly contain asbestos. Asbestos is only a concern if the particles become airborne. Keeping the linoleum wet while your removing it will prevent that.

After you remove the linoleum and underlayment make sure the planking is in good condition and is attached good to the joists. Replace any damaged boards, and use extra screws to secure it where needed. Add 1/2" of bc or better exterior plywood. Screw it to the planking avoiding the joists as best you can. No glue. Use plenty of screws. Once youve done this your options are cement board or a membrane.

I agree with HeresJohnny. Just want to add the fact that you need to leave 1/8" gap between plywood sheets. The 8' side of the plywood goes perpendicular to the joists, and stagger the sheets so that 4 corners do not meet. Also, if you use cement board as the next layer over the plywood, the same principle applies as with the staggered joints. CBU's require a setting bed of unmodified thinset along with mechanical fasteners and fiberglass tape. Good luck. Jim