Flooring Tile - KitchenCounter tops

Redoing kitchen counter top completely. Tile we brought is porcelain and Iam getting conflicting information on installing it. Some say to use Plywood with mastic others are saying to use plywood with backer board and non-sanded thin set. Grouting is another issue, are there special grouts for counter tops and if so what are they.Sealing the grout seems to be another issue would you are wouldn’t you and why? Grout lines will be 1/8 wide.
Any help would be greatly appreciated thanks.

Using concrete backer board underneath is always best. Use a quality thinset. Many folks opt for epoxy grout because of its durability. It can be, however, a challenge to work with for the inexperienced. If you used a polymer based grout, you can opt to seal it because of its exposure to moisture and potential staining.

Install the backer board following manufacturer's directions. Use polymer modified thin set on porcelain tiles. Home Depot carries Custom's Versa Bond, for example. Do not use mastic.

Joints 1/8 or wider require sanded grout, and sanded grout works better on porcelain, anyway. Seal the grout thoroughly.

http://www.aquamix.com

http://www.stonecare.com/

Thank God for this Web site and all the replies.
Here’s a great idea. This web site needs to be posted at all stores that supply material for the Home do it your self people. Sure would save a lot of time and headaches.
Could you please tell me the difference between ½ inch wonder board, ½ inch cement board, 1/4 inch hardi board. Could this ¼ inch Hardi board which states for tile be used with the same effect as the ½ inch
cement or wonder board on the counter top. Home depot doesn’t sell these boards in 4’ X 8’ sheets come in smaller sizes which gets expensive. They now sell a 4’ X 8’ sheet of hardi board for the out side siding
which is 5/16 inch thick. Talked with some Home Depot people but like everything else they say its OK but they also said to use mastic for the porcelain tile. Would any one know of a web site that I could check this out.

Wonderboard,Duroc, concrete board are all basically the same thing...concrete with fiberglass mesh on both sides, holding it together. Hardiboard is a cement/fiberboard. Since you already have plywood down, the 1/4 hardiboard will work fine. Just do as the other gentlemen suggested and use thin set. All the boards come in different sizes..mostly 32"X5' in my neck of the woods, but also in larger sheets. John Bridge doesn't use backerboard, but he still has a great site you should check out.
http://www.johnbridge.com

Actually, I think I might use backer board the next time I do a tile countertop. It seems to me that bonding the stuff to the formica or whatever with multi-purpose thin set and then nailing it in good will stiffen the counter sufficiently. I do like the look and feel of the Hardie product.

Thanks for the plug, Adanac. The only thing you'll never get me to use is mastic.

John