Installing a corner lav (before or after tile)

[Jb9]

Hello,

I am getting ready to tile my bathroom (been waiting a LONG time)... I have a corner sink with the 2 slots/valleys where the posts that protrude from the wall will hook on. I'd like to drill the holes before the tile so that I get a good result (and can see the vent) but I am concerned I'll drill the holes incorrectly since the complete wall assembly isn't really in place. Do you think I'd be better off waiting until after I do the tile and then drilling it all in one shot? Could I even drill it after I put up the foam backer board? I ordered my tile so I should have the tile and backer board on hand. Here are some pictures of the wall and my carpentry. Sadly, I had to use 3/4" ply for backing on one side because the vent stack is right there. I feel confident I won't damage the vent (I can protect it when I drill) but I'd be curious to hear how some of the pros here might approach it.

Also, what is the stuff on the installation instructions? A gasket to prevent porcelain on porcelain?

Thanks.

 

[Terry]

If your measurements look good now, then you should be good. I would think it would be easier to tile first and then drill.
Have you checked to see how the p-trap is going to work there? The drain looks very close. Sometimes when they are close to the wall, I like to "miss" so that I have the option of swinging back on it. Or at least towards the drain. If it fits though, you can aim dead on.

 

[Sponsor]

 

[Jb9]

Thanks Terry. The drain appears to be dead on (maybe 1/16" off). The lateral distance is about 8 1/2" so hopefully that is enough for a 1 1/2" P-Trap.

 

[Reach4]

Thanks Terry. The drain appears to be dead on (maybe 1/16" off). The lateral distance is about 8 1/2" so hopefully that is enough for a 1 1/2" P-Trap.

Coming off at a 45 or other angle can give you extra swing for the trap. Your photos don't show that area.

If it lined up exactly (or closely enough), you could use a bottle trap. That would look nice with your non-enclosed sink. While bottle traps can be forbidden, there are once with plastic for the important parts that are allowed. I don't know how close is close enough.