Drainage systems (countertop, dishwasher, drain, sink)

[james.parera]

Hi All
one of my cline has recently changed his double drain sink with a single drain sink.
I now need to redo all the plumbing to allow for single drain usage.
I am having a hard time trying to find what is the proper way to install the disposal and dishwasher to a single drain,
and at the same time what is the proper layout of the PVC piping.



we will highly appreciate your feed back.
Thanks in advance.

[Barking Spider]

If you don't know, I suggest you call a plumber and make sure it is done right.

[jimboburnsy]

Originally Posted by james.parera

Hi All
one of my cline has recently changed his double drain sink with a single drain sink.
I now need to redo all the plumbing to allow for single drain usage.
I am having a hard time trying to find what is the proper way to install the disposal and dishwasher to a single drain,
and at the same time what is the proper layout of the PVC piping.



we will highly appreciate your feed back.
Thanks in advance.

There shouldn't be any problem. The disposer will only have one drain connection and one dishwasher connection. This should actually be much simpler than hooking up a double drain sink. You'll have a horizontal section that must be level or graded slightly down from the disposer to a 90 degree elbow, then a vertical section that runs straight down to the P or S trap, depending on the configuration of your drain lines.

The dishwasher will need to either have an air gap penetrating the countertop or simply be "looped" under the sink. Mine is looped. It's simple, free and works just fine to prevent backdraining into the dishwasher. To loop the dishwasher drain line, (this is a very general summary) you can simply zip-tie it to the highest point possible under the sink. EDIT: This "highest point" needs to be at a bare minimum higher than the sink drain.

[desertsun41]

Originally Posted by jimboburnsy

There shouldn't be any problem. The disposer will only have one drain connection and one dishwasher connection. This should actually be much simpler than hooking up a double drain sink. You'll have a horizontal section that must be level or graded slightly down from the disposer to a 90 degree elbow, then a vertical section that runs straight down to the P or S trap, depending on the configuration of your drain lines.

The dishwasher will need to either have an air gap penetrating the countertop or simply be "looped" under the sink. Mine is looped. It's simple, free and works just fine to prevent backdraining into the dishwasher. To loop the dishwasher drain line, (this is a very general summary) you can simply zip-tie it to the highest point possible under the sink. EDIT: This "highest point" needs to be at a bare minimum higher than the sink drain.

While this makes sense to me I suspect to a DIYer it might be like trying to read Chinese. Jimbo I would have no idea how to explain this by writing it and do it such as to have some one know what on earth Im trying to explain.

So I have to suggest to call a Plumber.

[jimboburnsy]

Originally Posted by desertsun41

While this makes sense to me I suspect to a DIYer it might be like trying to read Chinese. Jimbo I would have no idea how to explain this by writing it and do it such as to have some one know what on earth Im trying to explain.

So I have to suggest to call a Plumber.

Probably right. Wise man = The one calling a plumber.


James: Are you a renovator? I think you said that this was for a "client"

[lakerat]

This topic interests me because as a non-plumber DYIer, I found out the hard way how not to connect a dishwasher drain to a garbage disposal.

Mistakes:
#1 Not reading ALL of the installation instructions before installing the disposal.

I installed the disposal in the base of the sink fine but failed to knock out the plastic block in the inlet nipple for the dishwasher drain on the side of the disposal.

Once I read the directions and knocked out that plastic block I reconnected the dishwasher drain line but it still would not drain correctly.

#2

Once I read all of the directions for the dishwasher installation I realized the dishwasher drain line had to be raised to a higher level than the disposal inlet nipple on the side of the disposal prior to connecting to the nipple. I fixed that by using an extra long piece of flexible rubber hose and making a higher level loop and securing it to a higher point under the sink with a zip tie like Jimbo siad.

Then it worked fine.

After experiencing those problems myself I now know what ya'll are talking about.