Installing a new double sink vanity top in a bathroom. Does one typically place the back and side splashes on top of the vanity top (thus 4" high), or behind and to the side of the top (thus ~3 1/4" high)? I expect this is just individual preference. What I'm most interested in is if there is a good reason to NOT place it behind and to the side of the vanity top. Thanks.

[ATTACH]45842[/ATTACH] I am installing a new fiberglass corner shower in my basement. The old shower was set below the studs on top up the concrete floor. When I tore up my old fiberglass shower base I discovered the previous owner had "built it up" by using some pressed boards- they were disgusting and disintegrated on touch. I need to "build up the shower base to match the old drain height and so that the shower will be even with the rest of the new tiled floor. Does anyone have suggestions of how I can build the shower base up and what materials I should use to do it? (I probably need to build it up about 12 inches to match the floor.) Thanks!