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PLUMBING SYSTEM INSPECT DIAGNOSE REPAIR
AGE of PLUMBING MATERIALS & FIXTURES
AIR DISCHARGE at FAUCETS, FIXTURES
BACKUP PREVENTION, SEWER LINE
BLOCKED DRAIN REPAIR METHODS
CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CHLORINE IN SEPTIC WASTEWATER
CLEANOUTS, PLUMBING DRAIN
CLOGGED DRAIN DIAGNOSIS & REPAIR
CLOGGED SUPPLY PIPES, DIAGNOSIS
CLOGGED SUPPLY PIPES, REPAIR
CLOGGED SUPPLY PIPES, HOT WATER
CONDENSATION or SWEATING PIPES, TANKS
CROSS CONNECTIONS, PLUMBING
DEBRIS in WATER SUPPLY, Water Heater
DEPTH of DRAIN & SEWER PIPES
DEPTH of SEPTIC TANK
DRAIN & SEWER PIPING
DRAIN LINE DEPTH
DRAIN a WATER HEATER TANK
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOODED HEATING EQUIPMENT REPAIR
FLOODED SEPTIC SYSTEMS, REPAIR
FLOODED WATER HEATER REPAIR
FLOOR DRAIN / TRAP ODORS
FLUSHOMETER VALVES for TOILETS URINALS
GAS PIPING, VALVES, CONTROLS
GALVANIC SCALE & METAL CORROSION
GALVANIZED STEEL PIPING
HARD WATER - SOFTENERS
HEAT TAPES, Heat, Insulation prevent Freeze-Up
LEAD POISONING HAZARDS GUIDE
METHANE GAS SOURCES
MIXING / ANTI-SCALD VALVES
MUNICIPAL WATER PRESSURE IMPROVEMENTS
NOISE CONTROL for PLUMBING
NOISE, PLUMBING DRAIN DIAGNOSIS
NOISE, PLUMBING DRAIN REPAIR
NOISE, PLUMBING CHECKLIST
ODORS GASES SMELLS, DIAGNOSIS & CURE
ODORS IN WATER
ODORS, SEPTIC or SEWER
ODORS SEWER GAS in COLD WEATHER
ODORS, SULPHUR SMELL SOURCES
OUTHOUSES & LATRINES
PIPING IN buildings, Clogs Leaks Types
PLUMBING FIXTURES, KITCHEN, BATH
PLUMBING NOISE CONTROL
PLUMBING VENT DEFINITIONS & CODES
PLUMBING VENT DEFECTS & NOISES
PUMPS, WATER REPAIR
REPAIR BURST LEAKY PIPES
SEPTIC SYSTEM INSPECT DIAGNOSE REPAIR
SEWER BACKUP PREVENTION
SEWER GAS ODORS
SEWER LINE REPLACEMENT
SEWAGE BACKUP, WHAT TO DO
SEWAGE BACKUP TEST & CLEANUP
SEWAGE BACKUP PREVENTION
SEWAGE BACKUP TEST & CLEANUP
SEWAGE & SEPTIC CONTAMINANTS
SEWAGE CONTAMINATION in buildings
SEWAGE CONTAMINANTS in FRUIT / VEGETABLES
SEWAGE EJECTOR / GRINDER PUMPS
SEWAGE NITROGEN CONTAMINANTS
SEWAGE PATHOGENS in SEPTIC SLUDGE
SEWAGE PUMP CLOG DAMAGE
SEWER BACKUP PREVENTION
SEWER GAS ODORS
SEWER LINE REPLACEMENT
SHUTOFF VALVE LOCATION, USE
SULPHUR & SEWER GAS SMELL SOURCES
SUMP PUMPS GUIDE
SWEATING (CONDENSATION) on PIPES, TANKS
TOILETS, INSPECT, INSTALL, REPAIR
TOILET FLUSHOMETER VALVES
TOILET INSTALLATION PROCEDURE
TOILET OVERFLOW EMERGENCY
TOILET PLUGS, SEWER BACKUP
TOILET REPAIR GUIDE
Toilet Types, Flush Methods
TOILETS, DON'T FLUSH LIST
TRAPS on PLUMBING FIXTURES
WATER HAMMER NOISE DIAGNOSE & CURE
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE & FLOW MEASUREMENT
WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS\
WATER QUALITY TESTS, CONTAMINANTS, TREATMENT
WATER QUANTITY IMPROVEMENT
WATER SHUTOFF VALVE LOCATION, USE
WATER SHUTOFF VALVE, WELL PUMP
WATER SOFTENERS & CONDITIONERS
WATER SUPPLY & DRAIN PIPING
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TREATMENT EQUIPMENT CHOICES
WELL PUMP PRIMING PROCEDURE
WELLS CISTERNS & SPRINGS
WINTERIZE A BUILDING
This article defines plumbing vent system terms, distances, and functions, and other specifications and code requirements. We explain how plumbing vents work on buildings, why plumbing vent piping is needed, and what happens to the building drains when the vent piping is not working. We define the soil stack, waste stack, wet vents and dry vents, and we summarize the distances permitted between plumbing fixtures and their vent piping. We also explain how sewer gas odors m may be traced to plumbing vent problems. Contact Us by email if you are having trouble finding the information you need.
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Our page top sketch of a plumbing stack vent and other sketches included below are provided courtesy of Carson Dunlop Associates.
At PLUMBING DRAIN NOISES we explain the basics of proper plumbing vent piping and how errors cause trap siphonage, odors, and noises. We discuss how to diagnose and cure drain sounds at PLUMBING DRAIN NOISE DIAGNOSIS. Other advice about controlling plumbing noises in buildings is at SOUND CONTROL for PLUMBING. More details about plumbing drain line venting can be found at PLUMBING VENT DEFINITIONS & CODES, also PLUMBING VENT DEFECTS & NOISES and at CLOGGED DRAIN DIAGNOSIS & REPAIR.
2. Allow sewer gases to be vented safely outdoors. Because sewer gases may flow back up into the building drain piping from a public sewer or private septic system, and because some sewer gases are included in building waste flowing through the piping, the plumbing vent system needs to carry these gases outside, usually above the building roof, where they are disposed-of safely and without leaving unpleasant, or possibly dangerous smells and gases inside the building.
The basic plumbing vent terms are shown in the sketch at left. In these notes, the plumbing stack vents and other sketches included below are provided courtesy of Carson Dunlop Associates.
The waste stack pipe shown in the sketch refers to any other vertical drain piping in the building that does not carry soil (sewage) from a sanitary fixture (toilet). Typically waste stack piping carries drainage away from sinks, tubs, and showers.
Below our tables 1 and 2 summarize common plumbing code specifications for fixture venting and vent pipe sizes and distances that a plumbing fixture can be located (horizontally) from the vent stack. You'll see these distances also in our sketch at left. [Click any image to see an enlarged, detailed version.].
Within the building the plumbing vent routing is generally unrestricted. That is, dry vent piping carrying only air, sewer gas, or moisture to above the roof line is unrestricted. However the piping does need to be protected from nails - use nail plates to protect vent and drain piping both where where piping passes through studs, joists, or rafters.
But a wet vented fixture requires a larger drain pipe diameter in its wet portion as we show in the sketch. This diameter increase helps assure adequate air flow into the drain system in the event that the sink basin (in this example) happens to be draining at the same moment that the toilet is flushed. (908.2.3.)
Also note that wet vented fixtures (toilet, bathtub, shower, or floor drain) are permitted for bathrooms on the same floor level, not between floors.
The table below gives required clearance distances to various building features and cites pertinent model plumbing codes.
Plumbing Code Citations for Plumbing Vent or Vent Stack Clearance Distances
Quoting model plumbing code such as the IRC:
Plumbing Code Citation References
Frequently Asked Questions (FAQs) about plumbing vent installation, definitions, & clearance distances
Question: can the soil stack curve above ground to avoid a wall?
I am trying to find out if the soil stack can be curved above ground because there is a wall that I need to move. The wall will moved about 1 1/2 feet and the soil stack is currently inside the wall that I desire to move. This is in Portland, Oregon. The pipe that was used for the soil stack is cast iron, but I want to change this to the black ABS. Are there restrictions to how much the pipe can be curved? - Enan
Take a look at the UPC (see citations in the article above or at "References" below. Certainly I've seen plenty of soil stacks (vent piping) that were not straight runs in above-ground (or above building) routing.
Actually the part of the pipe that I wanted to curve would be down in the basement below the water closet (toilet, sink, and shower)There is only 1 restroom in this house. This means that the part that is curved would be under load from all the water draining from the sink, toilet, and shower. I was trying to avoid tearing up the concrete floor to install new drainage pipe and also because of how close the soil stack is to the cement wall in the basement. The basement is not a full basement, but about a quarter of it is still crawl space which has been framed, and drywall installed (its used for storage). The soil stack runs next to this wall that is half concrete half drywall. My plan was to cut the soil stack about three or four feet above the concrete floor and then do a 45 degree turn until the pipe enters the drywall portion of the partitioned wall and then have it go straight up to the roof. Do you know if that might cause a problem with the pipe being under load from the drainage of the water closet? I planned to change everything above the cut that I make into the cast iron pipe with ABS. Of course I would brace everything that needs to be braced.
Question: Can a sink and toilet share the same waste line and vent?
Can a sink and toilet share the same waste line and vent? - Jim
Reply: Yes but ...
Jim: yes vent piping can be shared, but all fixtures need to meet the distance requirements.
Question: drain trouble in a new house - bubbling lower floor toilet and slow drain
I just moved and seem to be having trouble with the drained in the new house. When someone is in the shower upstairs air bubbles come from the toilet downstairs. If you try to flush the downstairs toilet the water will not drain. Just wondering if anyone knows what the problem might be and what I can do about it. Thank you. - Lucas
Question: one sink drains slowly and doesn't seem to clear - could it be a vent problem?
All the sink and toilets drain great in the house but one sink in the upstairs bed room. I have ran a snake, many times pipes are clean. Drain will handle water slowly. But if I fill the sink open the plunger or even take it out, it take an extremely amount of time to drain Could it be the dry vent if so, How Do I Clean it Thank you for you time. - Larry Miller
Follow-Up Comment: Derek Plumber offers more advice on clearing a blocked drain
A snake does not always completely clear a clog, blockage depending on how long it has taken to build up the blog, blockage can mean a difference in how you approach. Of course start with a snake the issue u have with it still draining slow is most likely that as you have gone through the clog, blockage and pulled the snake out that the Black Tar is just collapsing back on itself thus making it nearly impossible to clear with a snake.
If you have it draining slow this means that you have only cleared a path through the clog, blockage and that the issue is still there and will eventually blog up again.
You can try running your HOT water slowly while using your snake in a back and for motion many times over attempting to pushing what breaks free and is small enough for the water to push through ... a plunger will have little effect in forcing this down the drain.
This may or may not work.
Your best approach at this point, now that it will drain is to use a power flusher (you may be able to rent one)the hose is sized for the drainage pipe your working with, this works by spraying high pressure water usually min 1500 psi through the hose which has a variety of different heads attached to end. Id suggest using the head that has 3 holes spraying backward as it will help u by pushing itself through the pipe.
Make sure the hose is a good 3 feet in the pipe and u have a firm grip on it where it enters the clean out turn it on and run it slowly down back and start over till it is good and clear. - Derek Plumber
Question: how to move a toilet across the room - drain vent pipe distance trouble
I am trying to move a toilet 8 feet across a room, meaning that my venting pipe will be farther away than 5 feet. If I use the same soil stack, sloping the drain pipe 2 inches down over the 8 feet, do I need to add another vent stack pipe closer to the toilet to allow for air to escape, or can I allow the toilet to vent off of the existing vent stack? If I need to tap another vent stack into the line, any recommendations on how that needs to work?
Steve, if the toilet waste line is 4" or more ID, one of the sketches above, as I read it, says you can go up to 10 feet away from the soil stack. Make sure you have proper slope as well.
Can I have 3 toilets on 3 different floors connected to the same vertical 3 inch soil pipe without separate vent pipes also added? Other wet vented fixtures are connected upstream from the toilet on the 2nd floor, which is the highest floor. - Larry Gatti
Larry, yes; you will need to review DWV layout schematics in the model codes or training manual.
Question: definitions of discharge stack, waste stack, vent pipe
what is differentiate between discharge stack,waste stack and vent pipe. - Yana
I take those terms to all refer to the vent pipe
Question: can water in the basement come from a leaky vent stack drain line?
When I have a heavy rain I have a puddle in the basement next to the bathroom drain pipes. This only happens during a heavy rain storm. Could I have a leak around the bathroom vent pipe? - Ray
Reply: yes but ... check these two other wet basement diagnosis clues
Ray, I have seen a few cases in which leaky vent stack flashing at the roof allowed water to run down the outside of a vertical plumbing vent stack pipe that in turn was enclosed in a chase-way that ran from roof to basement - water might indeed then show up in the basement.
But there are at least two other things to check:
At BASEMENT LEAKS, INSPECT FOR we provide a series of inspection points useful for sure diagnosis of the cause of wet basement floors.
Question: how much clearance between plumbing vent discharge opening and top of brick chimney?
How much height clearance do I need between my plumbing vent discharge opening and the top of my brick chimney? Our vent pipe is located about 15 inches from the chimney. Chimney and vent are near the ridge (peak) of the roof. - Tim L.
Reply: Two feet or 24" is a code interpretation for distance between plumbing vent stack rooftop termination and the top of a chimney that is less than 3 ft. away.
Tim L - thank you for your question. I've reviewed and edited our section above on plumbing vent clearances to give code citations and details. I don't find chimneys explicitly named in plumbing vent sections of the model codes, but the distance to the "Nearest window, door, opening, air intake, or ventilation shaft" distance to plumbing vent needs to be 10 ft. horizontally OR the vent should terminate at least 24" (two feet) above the opening. I take this to include chimneys.
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