The black plastic is just a guide for finding locating the fixture. It comes off and gets tossed. You may be able to make the hole smaller, so test assemble the rest of the fixture. Generally though, that is what you cut around.

 

Really? I'm confused... the instructions didn't seem to mention unscrewing the plastic and removing it afterwards... I can't on the website right now to double check because its down... Are you saying I should have removed the guide and my underlayment should have been just cut around the valve part?

 

You can make a template the size of the tile out a piece of paper.
Place the paper over the tile , push it over the pipe and it will rip the paper.
Then make sure everything is lined up properly and draw a circle with your drill attachment. Place the paper template over the tile and cut with our circle drill attachment. You may have to sand the inside a little if you're cut is off, or use your tile nippers.

Hope that helps.

 

Thanks NIA - my question isn't so much about how to do the cutting, rather what to cut out... I was asking if I should cut the tile just around the part that comes out of the wall or if I should cut around the whole plastic piece...

 

I had the same question when I put Durock around my tub recently, and I asked my plumber how big to make the hole for the valve, and he said to do exactly what you did -- follow the plastic.

 

Did this apply to the tile as well? Thanks

 

I cut around the piece that comes out of the wall.

 

When I am tiling around my mixing valve, do I cut around the whole thing, IE the big black plastic circle or just the part that actually protrudes from the wall where the handle goes?

Thanks.

The black plastic piece is simply a gauge that shows how close to cut the tile or wall board (durock, Hardi, etc) to the valve. Cut around it as close as you can or remove it and cut your hole smaller than the black plastic gauge, just as long as you don’t cover the holes for the bolts. If you look at the black plastic piece you’ll notice two bolts diagonal from each other holding it in place. Unscrew those bolts to remove the plastic piece. Then when you cut your wall board or tile around the valve make sure it doesn’t cover those two holes where those bolts screwed into the valve. You can cut it pretty much as close as you want as long as you don’t cover those holes to attach the trim piece.