I would only suggest adding concrete board on top of the wood.

Hazie

Call your local building inspector first. Ask about extra load bearing joists under the kitchen floor and what's required for marble countertops. You're adding a LOT of weight.

Also - how thick are the pieces or marble? If they are really thick your countertops will be too tall for "normal" folks ( I'm thinking 24" high is standard but I'm not positive).

Hmmm ... I didn't think about the weight. I'm pretty sure that hubby can reinforce the cabinets, but I didn't think about the weight on the slab foundation. I don't think the marble would be heavier than granite and lots of folks add granite counter tops without foundation/slab issues.

Good point - I'm gonna ask the expert about this ... luckily if I don't like his answer I can put my cold toes on him until he figures out a way to make it work :-)

icheer, my cousin has marble countertops made with tiles usually used for floors. Her brother is a tile setter. The one thing they did differently with the marble is put it real close together. You really can't see the seams unless you get your nose right up there. I don't think they used grout because of that. I am out of town and so is my cousin so can't get anymore details for you. My daughter also has marble tiled floors and it is the same, the seams are so small there isn't any grout. So you might want to check this out because it might be different for marble.

HAZIE is right about the hardibacker over the plywood. If you can dream it up, you can do it, but remember that marble stains.

Here's a pic of my bathroom countertop off the laundry room. Did this before I found this forum. I just wanted a quick fix for the ugly laminate. Ripped it off and sealed the plywood base. The pieces are the ones you buy on the mesh at HD, etc.I didn't have any way to cut them so that's why some of the grout lines are way too big. And I used unsanded grout - don't ask me why. Since it's small, didn't add that much weight or height.

Here is a link that might be useful:

Thanks for all of your input. I think I need to put more thought and planning into this project instead of my usual style of jumping in with both feet! I may do a small sample board and set it on part of the counter top to see how it withstands daily use and abuse by my teenagers who're rotate kitchen duty :-)

(no, you can't borrow my teenagers for KP - they're the last two of six and they're aging out fast!)

Cherie