My opinion.

Ideally your tile should be level with your tub. So the backer should butt the raised edge of the tub.



ED

 

So cut the backer to fit inbetween the wall and the flange? Like I did in this picture?

 

Yes , if that gives you the space needed to get the tile level with the tub edge, because you do not want any splashed water to run anywhere but back into the tub.



ED

 

Caulk the seam and waterproof with AquaDefense.

 

And the tile is almost never level with the tub rim. Even if it were that wouldn't encourage the water back into the tub.

 

OK thank you guys. I'm gonna use redgard and caulk the seems....mortar under the hardie and screw it down correct? I bought the green square headed screws that say for hardie m do I have to predict the holes since the screws are not self tapping? Thx again

 

Sorry auto-correct.....do I need to predrill holes

 

Pilot holes will not hurt, and can help in keeping your screws from wandering upon installation.


ED

 

OK awesome.....now I know I need to mud and tape my seams....should the mortar under the hardie be wet or dry as I tape my seams with new mortar or does it not matter