Venting Plumbing for Remodel - Upside down P-Traps Possible?
John 9a
13 days ago
last modified: 13 days ago
Featured Answer
Sort by:Oldest
Comments (28)
klem1
13 days agoJoseph Corlett, LLC
13 days agoRelated Discussions
Plumbing Drain Avoiding Siphoning
Comments (2)Your proposed set-up won't work and will need venting. Under most plumbing codes, the maximum distance between the sink trap and its vent is 8 feet of developed pipe length. You have several options to achieve proper venting without having to resort to an AAV. One is to run the fixture vent out through the side wall. This can be by venting upwards within the stud cavity as high as you can go and then out of the building to where it will terminate. As long as you have proper clearances above ground (usually 10 feet), from property lines (usually 10 feet) and to openings (ie. windows, doors, air intakes) in the building (usually 3 feet horizontal) you can vent through a sidewall. Another is to install an 'island vent'. An island vent takes advantage of venting downward below the floor level and then up and out to the vent system. You can see a typical island vent configuration here: http://www.plumbinghelp.ca/images2/Island%20loop%20vent.jpg Lastly, you can use a "Combination waste and Vent". A Combination Waste and Vent uses larger than normal drain sizes for the fixture drain of a sink to serve as both a drain and a vent. Typically the 1 1/2" vertical drain from the sink must immediately enter a horizontal waste pipe that is normally at least 3" in diameter if serving both a sink and a dishwasher, and this horizontal drain must be vented. The The drawback to a Combination Waste and Drain configuration is that waste grinders (garbage disposals) are prohibited from being used with them. Call your local plumbing code office for assistance. Chances are there is a relatively simple answer and option for your dilemma. Luck....See Moreshower drain vent
Comments (4)Thank you so much for your swift and wonderfully detailed response. Your knowledge and experience is a great help to us. First, let me say that our initial gray water system drain setup was just a test to see how it was working before we finalized the system. We had plans to drain into a storage tank system if we exceeded the Tucson, AZ gray water guidelines which are much less stringent than Californias gray water guidelines as a result of AZs restricted supply of fresh water and our states desire to conserve the limited fresh water supply we have. Fortunately, we do not exceed our local gray water guidelines as our gray water is only from one shower and does not run off of our property. If I understand your statement: "if you have a 2" pipe with a ¼" per/ft pitch the maximum distance from the trap weir (the point on the trap where the inverted U section turns horizontal on the output side) to the vent opening may not exceed 2" / .25" = 8" then we are OK as our vent pipe is almost exactly 8 from the trap weir. Im not sure what this means: "Under the Uniform Plumbing Code the maximum developed length of a 2" waste arm may not exceed 5." But since we are under and are within the specifications of - the local Tucson, Pima County, AZ plumbing gray water guidelines it might not matter. Do you happen to know whether there is a limitation on how far we can run the drain before the actual drain opening into the perforated pipe youve proposed? Right now, our run is about 60 from the drain in the shower to the end of the gray water drain pipe. Regarding the vent pipe rise: I can replace the 2 flat vent pipe run with a 45 degree bend then take that directly to the 10 vertical vent pipe. Or replace the tee and this time turn the tee up and set the branch off point from the tee to the vent pipe at 45 degrees instead of (almost) parallel to the ground like the existing one is set. Thanks for clarifying this for me. I believe federal law supersedes state and local law. However, the AZ Department of Environmental Quality clearly spells out the guidelines for using gray water at home in Arizona. I have pasted an excerpt of the guidelines at the end of this posting, along with the web address for the entire brochure. Thank you also for the estimation of water usage per person per shower: "2 occupants x 25gal/person = 50gallons/day" There is nothing else hooked up to this gray water drain system, only this one shower. So 50 gallons/day is about how much water will be going out for gray water irrigation. And this information you gave us is invaluable: "You could then connect your pipe to a perforated pipe, which has a minimum volume of 50gal, but the total overall length of the perforated pipe may not exceed 100. A 3" pipe has a volume of 2.75gal/ft so a 3" line 137.5 long would contain 50gal, however, the length of the line exceeds the maximum allowable length of 100 so you would have to increase the line to 4" diameter. A 4" line has a capacity of 1.53/gal so you would need 50gal x 1.53ft/gal = 76.5 of 4" perforated pipe." This formula will help us calculate what kind of leach field we need based on the length of the run of the perforated portion of the drain pipe. The entire width of our back yard (the part were trying to irrigate) is not much more than 70. Right now, the gray water from a 10 minute shower wont even make it to the end of the temporary test trench I dug from one end of our lower back yard to the other. And the water never even runs off anywhere into the back yard at 102 degree Fahrenheit average daytime / 90 degree Fahrenheit average evening temperature the water doesnt even sit in the trench very long. What doesnt get absorbed into the dirt right away evaporates pretty quickly even in the evening. So I feel confident that were not going to exceed the basic requirements from our local and state laws. The local plants and critters (lizards, ants etc.) are having a great time at our new back yard oasis though! My wife and I really want to thank you for all your time and for sharing your knowledge and experience. The information you provided will help us set up our gray water system so it is safe, efficient and environmentally sound. Thank you very much again. Here is the information I mentioned earlier: http://www.azdeq.gov/environ/water/permits/download/graybro.pdf The basic requirements to use gray water at your home are simple: Residents must adhere to the guidelines for a Reclaimed Water Type 1 General Permit. A Type 1 General Permit requires no formal notification to the department, no review or design approval, and no public notice, reporting or renewal. Although you dont have to apply to receive a formal permit for permission to use gray water, you must abide by the 13 best management practices (BMPs) listed in this brochure, which were developed to protect public health and water quality. Permit Eligibility and Usage Requirements The general permit is meant for private residential use only. Gray water must be used on the site where it is generated. The area of use cannot be accessible by the public. Under this general permit, gray water can only be used for irrigation not for dust control, cooling or other water uses. Only drip or flood irrigation with gray- water is allowed. Spray irrigation is not permitted due to the potential for inhalation or drifting off-site. Gray water flow must be less than 400 gallons per day. In general, no city, town or county may limit the use of gray water if the use is allowed by this general permit (ARS §49-204). For a copy of the gray water rule, call the nearest ADEQ office or download it at: www.azsos.gov/public_services/title_18/18-09.pdf. The gray water rule can be found in Title 18, Chapter 9, Article 7....See MoreNumber of turns in a trap drain
Comments (14)jsjames: I have read often that up to 135 degrees in total bends is OK. So, this means it is possible to have three 45-degree bends, but the full and complete answer will depend on the other factors concerning the pipe geometry in space (length, drop). I gave you key words to search on instead of trying to answer the question directly. As I am not a plumber, my wording of any answer might be imprecise (and thus wrong in some way). In previous threads when I have tried to give specific answers I have found my explanation was not precise enough so it was partly wrong and needed to be modified. -- The second response you received said you needed to upsize to a 2" pipe. This is wrong. A trap arm can be 1.5" all the way to the vent. A trap arm is not upsized to 2". A trap arm is the trap's horizontal "tailpiece" and its extensions, up to the vent. Thank you to manhattan42 for posting California code: -- Table 7-3 says "Min. Size Trap and Trap Arm" in the column header Both Trap Arm and Trap are considered together as a unit. Size Trap and Trap Arm Kitchen, domestic -- with food-waste grinder and dishwasher too 2 DFU 1-1/2" trap and trap arm The maximum length of a trap arm is not governed by this table 7-3. It is governed by the other principles I outlined in my first response. -- Table 7-5 says maximums 1.) Excluding trap arm. 2.) Except sinks, urinals, and dishwashers. The maximum length of a trap arm is not governed by this table 7-5. It is governed by the other principles I outlined in my first post. -- I understand a Master plumber might not like a non plumber trying to help in the first place (in my first reply above). I would have liked someone to congratulate me before adding any correction or additional information. I understand a senior contributor might want to add his additional input. I understand too that he/she can make a mistake just as I can and anyone else. I am disappointed that a serious contributor made a major mistake and then couldn't admit it. I am disappointed that he avoided answering the question posed. I am disappointed to note that I've seen this before: more and more Code quotes all serving to avoid the main mistake. I said that a kitchen sink is only 2 DFU after lazypup said 3 DFU and then he avoided this topic. I said that 2" pipe is not called for in new kitchens today; he avoided this too. I found more and more clear "Code" reasons why 1.5" pipe is Code-accepted; he avoided facing it. Every house has a kitchen. I am extremely disappointed that a supposedly practicing plumber doesn't know the size of a kitchen drain. This is evidence that we have a problem, in this forum. I am extremely disappointed to see that "excluding trap arms" was not quoted by lazypup when he DID quote the other words verbatim "except sinks, urinals, and dishwashers" ; this is another form of avoidance, and it causes more problems than ever when the MOST relevant information is removed from a direct quote or reference. This is usually seen as intellectual dishonesty. Many people will let the "main man" have his way... but I'm also disappointed in brickeyee for acting as a bully-follower (posting as if to confirm that 2" pipe is now required). We REALLY need to have more than one main person in this plumbing forum. That is why I wrote we need another plumber in this forum. Otherwise, this forum is just one guy's sandbox. And who will double-check him if he won't double-check himself? He may not even be lucid any more. I understand lazypup might not like this. hope this helps the forum and every one of its contributors. ....See MoreDrain and Vent Layout Help
Comments (1)Here's another picture of a proposed layout that makes the connection to the sewer line outside the house and also minimizes cuts in the slab. I'm concerned about cutting into the concrete sewer line and then cementing over it under the slab. I thought it might be better to have it in the yard where's it's more accessible. If anyone has any thoughts on this, I'd really appreciate it....See MoreZumi
12 days agoJohn 9a
12 days agolast modified: 12 days agoMinardi
12 days agolast modified: 12 days agoJohn 9a
12 days agoJake The Wonderdog
12 days agolast modified: 12 days agoJohn 9a
11 days agoKimberli Saunders
11 days agolast modified: 11 days agoHU-417513365
11 days agoJohn 9a
11 days agoKimberli Saunders
10 days ago3onthetree
10 days agolast modified: 10 days agoJohn 9a
10 days agoJohn 9a
10 days agoJohn 9a
9 days agoJohn 9a
9 days agolast modified: 9 days agoHU-417513365
9 days agoJohn 9a
8 days agolast modified: 8 days agoJohn 9a
8 days ago
Related Stories
MOST POPULAR8 Little Remodeling Touches That Make a Big Difference
Make your life easier while making your home nicer, with these design details you'll really appreciate
Full StoryBATHROOM DESIGN10 Things to Consider Before Remodeling Your Bathroom
A designer shares her tips for your bathroom renovation
Full StoryMOST POPULARContractor Tips: Top 10 Home Remodeling Don'ts
Help your home renovation go smoothly and stay on budget with this wise advice from a pro
Full StoryREMODELING GUIDES10 Biggest Remodeling Regrets and How to Avoid Them
We’ve asked a panel of experts to reveal the most common renovating mistakes — and how to steer clear of them
Full StoryREMODELING GUIDES5 Trade-Offs to Consider When Remodeling Your Kitchen
A kitchen designer asks big-picture questions to help you decide where to invest and where to compromise in your remodel
Full StoryFUN HOUZZ31 True Tales of Remodeling Gone Wild
Drugs, sex, excess — the home design industry is rife with stories that will blow your mind, or at least leave you scratching your head
Full StoryBATHROOM COLOR8 Ways to Spruce Up an Older Bathroom (Without Remodeling)
Mint tiles got you feeling blue? Don’t demolish — distract the eye by updating small details
Full StoryMOST POPULAR15 Remodeling ‘Uh-Oh’ Moments to Learn From
The road to successful design is paved with disaster stories. What’s yours?
Full StoryCONTRACTOR TIPSThe 4 Potentially Most Expensive Words in Remodeling
‘While you’re at it’ often results in change orders that quickly add up
Full StoryBATHROOM DESIGNBath Remodeling: So, Where to Put the Toilet?
There's a lot to consider: paneling, baseboards, shower door. Before you install the toilet, get situated with these tips
Full Story
John 9aOriginal Author