How would a pro deal with a ledge in a shower?

If you do take it out and rebuild, then make it a little higher so that the horizontal tiles go under the last full row of verticals, have a slight incline to the front to allow drainage.

 

A length of 25mm width upvc trim on top of tiles then facia board over , you could quadrant around edges.
If it didn't work I wouldn't have suggested it.

 

I'm sure it would...just a belt and braces approach

 

Well, I'm a bit of a 'ledge' in the shower if I say so myself.

How would a 'pro' deal with me? Well, modesty forbids...

 

I take it you mean that you're a bit of a 'leg end' in the shower in which case embarrassment should forbid...

 

Make the shelf much higher to use for keeping showering stuff maybe? Could box in and use space created behind for pipe work. Make it a little higher to use as a shower seat. Needs sloped tiles under a level wooden seat.