Hardi-board vs plywood under ceremic 20" tiles?

Question

I am wondering if I can save money using plywood as a subfloor for tile. It is new construction with a new floor of 3/4 inch compressed wood type of plywood. I have a lot of area to cover and thought I could limit the Hardiboard to the bathrooms and cheaper plywood for the rest. It is my home and I need it to last. Is it a bad idea? My contractor wants Hardiboard everywhere. Thanks for input!

I will be installing the tile myself

Hardi-board is a brand of cement board sub flooring

Answer 1

Key items in this question: Ceramic and 20 inch

You *must* use hardboard or cement board (not familiar with hardiboard) under this large a ceramic tile or you *will* be replacing cracked tiles. Actually, most reputable contractors I know would insist on putting a layer of mortar down for placement of these tiles. In this case you could use plywood under the mortar.

Answer 2

By all means, use the plywood and save money. They [including me] have used ply for years and it's lasted for years. They just come up with new ideas and say plywood won't last just to get you to buy the new crap. Plywoods fine

Answer 3

hardi board is a much better choice, it doesn't expand or contract with the weather. because you have wooden floors you must have excellent support for any type of tile.

my husband has been installing tile for 19 years. .

Answer 4

Never skimp on the sub floor. You need duroc or hardiboard, taped at the joints. Big tiles like you are talking about WILL (this is not maybe) crack.
Your contractor is not trying to soak you on this one.

Answer 5

would use nothing but hardi....will not deflect as much as plywood and holds up better......i will not allow my subs to use anything but hardi or dur-rock.......

lic. gen. contractor