Need advice on drain plumbing for new construction

snottyvar

snottyvar

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I hope my daigram attached. A couple of notes on the diagram: all pipe grades are 1/4 inch per foot, no 90 degree bends

As you can see I am wet venting my kitchen island by using a 3 inch pipe over 12 feet, actually I am wet venting both lav sinks and the shower. I live outside of municipal boundaries. There is no inspection at all except for electrical with is provincial. I still want to do it right. Any thoughts
Thanks a lot
 
A couple of corrections: The basin on the first floor does not feed into the WC drain but into the the drain on the left. No appkiances drain below a WC. Also there is a cleanout in the basement and on the drain from the kitchen island
 
I realize no one has the time to tell me exactly what to to. Is the problem that I need more venting. I researched this forum and found a two story stacked lavatory diagram with venting that I can approximate very closely but can I use the 3 inch drain from the island without venting?
 
I just got here and I'm annoying already. Correct me if I am wrong. The purpose of drain plumbing is to let water and waste exit the building without allowing any sewer gasses back in. Systems should be designed so that if all of the appliances are draining at the same time there will not be enough vacuum to pull any of the traps in the system dry. That is why venting is required on the drain side of the trap weir so there will be no vacuum on the trap to pull the water out. Using my initial diagram, if I put correct vents (ones that are above the flood level of the appliance) on my shower, tub and sinks would that make my system passable. Please remember there are no 90 degree bends, my drawing isn't great.
 
Generally speaking- on a vertical drain only the top-most connection is allowed to use that pipe as a vent. Every other trap arm below that must have a separate vent.

All of the vent connections can be interconnected once they are back up above the highest fixture on the stack.
 
Thank you. I have been building two homes, one for myself and the missus, and one for the family, grandkids etc and so far the plumbing has been the most challenging. It's not as obvious as it seems but I think I have a grasp on it now. I certainly appreciate the time of anyone who cares to comment and help out. I thought the land of cheese was Hollywood. Cheers
 
The easiest way to do it correctly would be to vent each fixture before it comes into a line that other fixtures are connected to.
Within the same bathroom group, you can wet vent a lav over a toilet or you can wet vent a lav over a tub, assuming you have 2" pipe acting as the vent at that point, or larger.

The island drain does not use a p-trap below the floor. That puts the vertical up to the sink too long. The p-trap needs to be on the same floor as the sink, unlike a tub or shower p-trap that is working with a fixture that is sitting on a floor. The sink is much higher, and that height creates the problem of forcing water out of the trap when it is dumped from that height.

You also can not wet vent between floors. Remember, it has to be within the same bathroom set, the same floor.
 
Excellent! Thanks for your time. One last question. In order to place the p trap under the island sink I have to avoid creating as s trap. If my trap arm is at least twice the diameter of the trap before the vertical that is ok? Now if my daughter doesn't change everything again I should be OK. Cheers
 
quote; I have to avoid creating as s trap. If my trap arm is at least twice the diameter of the trap before the vertical that is ok?

That does NOT avoid an "S" trap, it just makes it longer. To avoid an "S" trap you need a proper vent, or an AAV at the trap.
 
An island requires a special vent, strangely enough called an "island vent". Someone will post a diagram. As Terry brought up, you can take advantage of wet venting, but not bewteen floors. It does not take "all fixtures draining at once" to siphon an unvented trap.

There are a lot of details not shown on your diagram, such as type of fittings used, length of trap arms, etc. But if you keep at it we will answer all your questions!
 
revised plumbing plan.jpg

Attached is my revised plan. The LAV trap arms are 24 inches. The bath is 5 feet, the shower is 5 feet. I have gone to a 1 1/2 inch drain from the island as I have added the recommened venting for islands. How am I doing. Thanks
 
No way. Thats not gonna work. Several problems but the main one is your vent for the Kitchen sink would fill with water. It should be at least 2" pipe also.

The toilet on the left is not vented,your bathtub is drawn above the floor and its crown vented.

The upstairs shower wouldn't need a revent.
 
Ok. So I need to raise the island vent loop higher to avoid it filling and use two inch pipe. I drew the bathtub above the floor so you could see the connections better. Crown vented? Also, how is the toilel on the left not vented and the toilet on the right is? We're getting there. Thanks
 
Just checked out crown venting. That is an error in the drawing. The vent would be a couple of pipe diameters along the trap arm. I understand what I did wrong on the island vent as well. All that is left is the toilet bon the left. How do I vent it properly?
 
Hi guys. Hackney plumbing says my toilet is not vented. I've been researching for hours. I don't get it. Anyone?
 
dlarrivee. I think I've made great progress. Perhaps my drawing is not so good. I can easily match the diagram for Island venting I found on this forum. I've been pouring over books and this forum pretty much 24/7. I realize I can not expect to do the job of a professional plumber But the hack job I did on my last house has worked for years. I just want this house to be as professional as possibble. One day I might befriend a plumber and I don't want to be embarassed when he or she comes to visit. Your discouraging remarks do not help. The problem is the sublties. I have a code book and sometimes it's difficult to transfer the code to a specific situation. If you do not have time I understand and believe me I have nothing but admiration and respect for people who offer up their expertise to people like me me. So please, What is your main issue with this job? Thanks
 
plumbing again.jpg

Alright. New plan. Except for the Island I pulled this out of a code book. Two questions: How do I add the shower upstairs. Can I angle the toilet drain and do what I did in my second drawing? and is the island good? I did forget to sketch a clean out on the wet vent under the first floor basin and a cleanout on the main line out. You can assume I will have the right fittings as my plumbing wholesaler (who has an excellent reputation) will sell me the fittings as per my plan. Thanks
 
I just realized I can do this job by copying exactly the drawing Mr. Love was kind enough to provide. Within the framework of that diagram I can move the fixtures to where I need them and easily add another fixture to the vent stack for my island. My old brain is really hurtin' Thanks to all who offered their insight and thanks for this forum. Just thinking out loud and being challenged to do a proper job can really motivate learning. Cheers to all and thanks again. I'll leave you alone now.
 
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