I'm getting ready to remodel my bathroom and am looking for the proper way to install the hardy board (HB)in the tub area. I'm getting conflicting advice on the net and thought someone might be able to tell me the correct way to do this.

Does the HB set on the lip of the tub or does it fall down in front of the lip, if so how do you make it fit without curving. Do you have to shim the wall studs out the thickness of the lip, how much room to leave where the HB meets the tub.

Do you use a waterproof material behind the board or is the board enough.