Level a floor for tile

Jake asks:

I'm remodeling my bathroom and had to replace 2/3 of old plywood sub-floor. The floor is still not level. My wife wants ceramic tile. I bought the tile and cement board. Do I need to use self leveling cement to make it right before starting?

Jake's answer: 

Jake,

There are two ways to level your floor.

One way is to shim the plywood as you are installing it.  You can add shims to the existing sub floor or add shims on top of the joists if they are exposed.

The other way is to use self leveling products that can be mixed and poured.  This product can be more expensive but works very nicely. You can check out a product that can self level at Quikrete.com. I hope your wife is happy with the finished product.