question regarding plumbing ventilation

[quazimoto]

So I'm doing the renos to my parents house and I'm at the final place, the kitchen. We want to install a dishwasher near the sink since the house doesn't have one and I'm sure any potential buyer will want one. Prior to my father passing away he told me that there was a bunch of plumbing pipes hidding behind the cabinets where the so called dishwash would be placed. This is the only place where the dishwasher can go so take in mind it can't be moved around.

So essentially I removed the 3 cabinets to find the plumbing drain going down with the ventilation stack going up in this small boxed in portion of drywall.

What I would like to do would be to relocate the drain to the kitchen sink right back under the kitchen sink itself. The issue with this is that it requires that I snake the ventilation under the floor and then back up under the sink in order to ensure the ventilation stack is still above the drain.

The big part I'm unsure on is if it makes any difference that the ventilation piping will at one point be under where the sink drains. The physical connection to the ventilation would still be above the drainage to the sink though. I mean no water will be getting in the ventilation since it's going to be above the drain but the fact the drain will then go right down through the floor and back up I'm uncertain on.

Hopefully this isn't overly confusing. I'm just scratching my head looking at it.

[C_Dave45]

Originally posted by quazimoto
So I'm doing the renos to my parents house and I'm at the final place, the kitchen. We want to install a dishwasher near the sink since the house doesn't have one and I'm sure any potential buyer will want one. Prior to my father passing away he told me that there was a bunch of plumbing pipes hidding behind the cabinets where the so called dishwash would be placed. This is the only place where the dishwasher can go so take in mind it can't be moved around.

So essentially I removed the 3 cabinets to find the plumbing drain going down with the ventilation stack going up in this small boxed in portion of drywall.

What I would like to do would be to relocate the drain to the kitchen sink right back under the kitchen sink itself. The issue with this is that it requires that I snake the ventilation under the floor and then back up under the sink in order to ensure the ventilation stack is still above the drain.

The big part I'm unsure on is if it makes any difference that the ventilation piping will at one point be under where the sink drains. The physical connection to the ventilation would still be above the drainage to the sink though. I mean no water will be getting in the ventilation since it's going to be above the drain but the fact the drain will then go right down through the floor and back up I'm uncertain on.

Hopefully this isn't overly confusing. I'm just scratching my head looking at it.
whoa!! Way to complicated lol. You just tie the dishwasher drain into your existing sink drain. It's a flexible rubber house that attaches to a nipple into the side of the sinks P-trap. Just run the hose along the wall and through a hole in any cabinetry. (about a 1 1/2" hole)
Gimme a few minutes I can probably dig up a picture here. You don't need to worry about venting as the sink's drain is already vented. If you have a garbage disposal, it will have an attachment for the dishwashwer drain hose. http://www.dannylipford.com/images/article/how-to-install-a-dishwasher-6.jpg

Otherwise just tie into the drain via a connector: http://images.lowes.com/product/046224/046224005261.jpg
Here's the best pictures for explanation:

http://www.dannylipford.com/diy-home-improvement/how-to-install-a-dishwasher/

[quazimoto]

No the drain for the sink is not attached to the vent believe it or not. The sink drain seems to have its own separate drainage stack that goes right down to the cement floor in the floor in the basement. It literally has the connection that runs through the left side of the sink through another cabinet and then up the wall.

Trust me it's super crazy but the only thing I really need to know is if that vent can be at some points lower than the actual drain since I need to run it under the floor and then bring it back above the drain. IT's really the only way I can do it.

This is why I hate houses built in the 60's and 70's nothing but backwards crap.

[C_Dave45]

Originally posted by quazimoto
No the drain for the sink is not attached to the vent believe it or not. The sink drain seems to have its own separate drainage stack that goes right down to the cement floor in the floor in the basement. It literally has the connection that runs through the left side of the sink through another cabinet and then up the wall.

Trust me it's super crazy but the only thing I really need to know is if that vent can be at some points lower than the actual drain since I need to run it under the floor and then bring it back above the drain. IT's really the only way I can do it.

This is why I hate houses built in the 60's and 70's nothing but backwards crap.

Hmm...still don't quite understand. All drains will be vented. You might not see it, could be vented in the walls...but it will be vented somewhere...otherwise it wouldn't drain properly. As long as your sink drains properly now...you can just attach the dishwasher drain into it. Unless it was mickey-moused after the fact by a DIY'er and added onto the existing plumbing. Maybe take a picture and post it...but even the 60's and 70's had venting for plumbing.

[quazimoto]

No it has a vent but it vents through the side of the cabinet and then up the ceiling. So you see the drain under the sink goes right down but then it tees off for the vent which goes right across the cabinets on the left hand side of the sink and then right up the wall.

What I want to do is remove the section of the vent that runs in the current cabinets so that I can install a dishwasher but in order to do so I would need to run the vent underneath the floor and then back up by the sink. The vent would still be attached above the sink drain however it would run under the floor and then up.

[black_shadow_18]

Im pretty sure you cant have a vent go below then back up, but im not a plumber. try drawing a quick little picture and posting it up, that might help clear things up.