Hello,

I'm doing a remodel and I'm adding a dishwasher. My dishwasher will not be directly beside the kitchen sink, but rather diagonal from the sink. Rather than installing the dishwasher normal, using water and drian from kitchen sink and running hoses though a huge corner cabinet, I want to plumb my dishwasher separate. I have the hot water line ran, but have questions about the drain. What can I come up through the floor with for a drain? (1.5" PVC? ) How will my dishwasher drain hose tie into this? And will some type of vent or air gap be needed? I plan on running this dishwasher drain through the basement rafters and connect into the sink drain grey water in the basement. Any help is appreciated!

Hello,

I'm doing a remodel and I'm adding a dishwasher. My dishwasher will not be directly beside the kitchen sink, but rather diagonal from the sink. Rather than installing the dishwasher normal, using water and drian from kitchen sink and running hoses though a huge corner cabinet, I want to plumb my dishwasher separate. I have the hot water line ran, but have questions about the drain. What can I come up through the floor with for a drain? (1.5" PVC??) How will my dishwasher drain hose tie into this? and will some type of vent or air gap be needed? I plan on running this dishwasher drain through the basement rafters and connect into the sink drain grey water in the basement. Any help is appreciated!

This will be a major undertaking for the drainage. This will have to be treated like a washer drain with a trap and vent. You will also have to do one of two things with the discharge hose. You may not drop the hose under the floor line to PVC and connect direct to the sinks gray water drain line. Either install a air-gap or run the discharge hose in a high loop as soon as it exits the washer. But either way a separate trap and vent will have to be installed. Good luck, Tom

Thanks for the fast response, our plan was to put some type of pvc through the floor and then is there some type of reducer that could be used to connect the drain hose to the pvc. Also we planned on doing some typ of p trap right after the pvc comes out of the floor into basment then take the pvc over to sink drain grey water pvc. Can you tell me what an air-gap is? This vent you mentioned, do I have to run that to the out side of the house! Yikes. How do people install dishwashers in kitchen islands? Thanks again.

Thanks for the fast response, our plan was to put some type of pvc through the floor and then is there some type of reducer that could be used to connect the drain hose to the pvc. Also we planned on doing some typ of p trap right after the pvc comes out of the floor into basment then take the pvc over to sink drain grey water pvc. Can you tell me what an air-gap is? This vent you mentioned, do I have to run that to the out side of the house!! Yikes. How do people install dishwashers in kitchen islands? Thanks again.

Let me take your last question first which was, " How do people install dishwashers in kitchen islands?"
They discharge the washer into the disposal or a branch tailpiece using the kitchen sinks trap and vent. You don't have that option so you will have to trap and vent separately.

"This vent you mentioned, do I have to run that to the out side of the house?"
Yes, unless local codes allow a AAV, (Air Admittance Vent) this to be installed within 5 feet of the 2" trap and drain line or 3 1/2feet if you use a 1 1/2" trap and drain line.

" Can you tell me what an air-gap is?"
Air gaps and high loops,(see images) are there to prevent any dirty water from the sink or disposal from draining back into the dishwasher. A air gap is a mechanical device that mounts on the counter top. A high loop will loop the discharge hose up as high as it will go under the cabinet and secure it there. Both are effective, in the Tampa Bay Area we use the high loop when we install dishwashers.
Good luck, Tom