A plumber told me that in my town the plumbing inspectors want the dishwasher drain line tied in right above the trap under the sink, even when there is a disposal with a dishwasher drain port. Why would they want this done? I would think it would be better for the HO and the city to have the D/W drain to the disposal to reduce the possibility of large food chunks going down the drain and causing a blockage.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Learn how to patch drywall above a fiberglass shower without totally redoing everything.
Featured Video
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Fine Homebuilding Magazine
Fine Home Building
Follow
-
Fine Homebuilding
Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.
Start Free Trial Now -
GBA Prime
Get instant access to the latest developments in green building, research, and reports from the field.
Start Free Trial Now
Replies
The DW soap will eat your garbage diposal.
Who ever invented work didn't know how to fish....
I think the main concern is the possibility of cross contamination if the DW hose would back siphon a full load of fermented food stuff out of the disposal into the dishwasher.
Rings true for older models of DW....but air gaps and one way valves in the new DW's have cured that situation.
Our local plumbers do not to use a DW tailpiece as it can flood the sink basin that it is attached to and cross contaminate that area of the food prepearion area.
Current practice also mandates that new installation for Disposal is trapped directly to the sewer line and separately from the sink drain. thus preventing backup into the sink basin. The DW is connected to the Garbage disposal with an Air Gap or in line backflow preventer.
The soap thing is probably applicable to cheaply/poorly cast models of GD.....most of of the GD's I've seen die of motor failure. Some folks also use drain cleaners in disposals....sure shortens the lifespan.
.....................Iron Helix
I believe that that a good quality DW macerates food particles such that plumbing above the trap as your local inspectors "require" would be OK as long as you also looped the DW drain line to the bottom of the countertop (and secured it there) and then on to the above trap connection.
I had an air gap fixture in my first house 25 yrs ago that plugged up about once a month - a nuisance item. Just yesterday my neighbor was complaining about her DW not draining and I found her air gap fixture plugged. This is an older (12 yrs) DW. She claimed that "a little bit of water" always leaked from the fixture - and her kitchen floor shows it. Well, I by-passed her air gap and went directly to the disposer with the loop previously described. To the best of my knowledge, this meets code in our county.
Eric S.