Plumbing for a new whirlpool corner tub

Hello everybody - I need an expert advice here...

I'm installing a new 60x60 corner whirlpool tub in my master bath remodel and need to figure out a way to drain and vent it. I have an 8' horizontal run of 1.5 drain pipe in the subfloor that drains the sink on one wall to the opposing wet wall, and the sink has a vent pipe coming just above it in the wall.

So the question is.. can I connect the new tub trap to this horizontal run (about 3' from the sink wall) and use the sink drain pipe also as the drain of the tub and the sink vent as the tub vent, or this configuration is wrong? (would water flow up the drain and onto the sink maybe???) any advice on how to do it would be greatly appreciated!!

thanks!!

Ronen

drain

If you can get the water to flow uphill into the sink, patent the method you do it because incompetent plumbers have been trying to do it since the year Ipish. The main problem using your descsription is that a 1 1/2" drain pipe under the floor is really too small. The water from the sink may back up into the tub.

drain

hj said:

If you can get the water to flow uphill into the sink, patent the method you do it because incompetent plumbers have been trying to do it since the year Ipish. The main problem using your descsription is that a 1 1/2" drain pipe under the floor is really too small. The water from the sink may back up into the tub.

Click to expand...

Hey, thanks for the quick reply granted I'm a newbe at this... replacing the 1 1/2 drain with a 2" will be better in this case?

drain

ronenbu said:

Hey, thanks for the quick reply granted I'm a newbe at this... replacing the 1 1/2 drain with a 2" will be better in this case?

Click to expand...

I've added a drawing of the existing configuration and the suggested addition of the new tub trap at: http://www.borshack.com/Images/other/master-bath-plumbing.jpg

The vent for the sink only serves the sink. Would that still work (given the drawn configuration)? thanks much!

configuration drawing: