Thread: Traps

Anyone ever see this before type of configuration before? Not to mention it is supported with string and rope.

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Yes I have -- that's an S-trap and it's wrong. (Vented improperly.)

I agree with being an S-trap, but it does raise a question in my mind. How long does the top section of the S have to be before it becomes a P-trap? Then the vent can be some distance (don't have chart infront of me) from the trap.

No mater how long the riser or how far the trap to the 90 down with out a vent it is still an S-trap.

Here in Illinois S-Traps are not allowed. If they are allowed in your state, it still needs a proper vent.

How can you tell it's vented improperly? It doesn't appear to be vented at all. I'd like to know how much other goofy stuff there was in this house, compliments of the "string support" mechanic.

There is some formula of the ratio of the diamiter of the trap to the length of the trap arm, to not be an S-trap (hush...I think I hear the rustling of code books in Fla.) If the diameter of the drain is 2" the vent can be as far as 5' from the trap outlet. We can't see 5' in the picture, and don't know what the size of the drain line is.

Originally Posted by Scott Harris

How can you tell it's vented improperly? It doesn't appear to be vented at all. I'd like to know how much other goofy stuff there was in this house, compliments of the "string support" mechanic.

Not vented at all = not vented properly I agree with you what other issues does this place have... You have to love the "string support", also the water thats been leaking between the floor and the drain pipe, noted by the stains along the black pipe.

Originally Posted by Vern Heiler

There is some formula of the ratio of the diameter of the trap to the length of the trap arm, to not be an S-trap (hush...I think I hear the rustling of code books in Fla.) If the diameter of the drain is 2" the vent can be as far as 5' from the trap outlet. We can't see 5' in the picture, and don't know what the size of the drain line is.

From the photo, the Trap seems to be 2" and the line its draining into is 3" Now to make this a legal P-trap you have to lose the last 90 degree bend and replace it with a Tee, have the Trap drain into the side inlet of the Tee, and the vent come off the top. If you leave this trap as is and put a vent any where in the 3" line the trap is still a S-trap.

Water will only completly fill a horizontal pipe for a short distance. Hence the requirement that the vent in a branch arm is not closer than 2X the diameter of the branch arm pipe, to the weir of the trap. The vent has to be within a distance of the vent weir, it doesn't have to be at its first change in direction and does not have to be at a fitting T. I am not aware of a code preventing more than one 90 in a drain line, but would be interested in learning about it.

I don't see a concern with siphoning out of the trap because the 2" line is draining into a 3" line right next to the trap


Of course, I need to get a copy of the plumbing code as I am probably the weakest in this area.

Hi, all:

* "Up here" - Canada (West Coast = B.C.), the trap arm length requirement is MIN. 3 x the pipe diameter to avoid /avert the bad ol' S-trap configuration...

Hope this helps /clarifies (not sure how 'universal' as to other Codes, obviously) !


CHEERS &

Here's to good business !

"Up here" - Canada (West Coast = B.C.), the trap arm length requirement is MIN. 3 x the pipe diameter to avoid /avert the bad ol' S-trap configuration...

Hope this helps /clarifies (not sure how 'universal' as to other Codes, obviously) !

I was ref. 1985 UPC.. might be 3" by now?

HEre is a page from the Illinios plumbing code book of traps not allowed, the last one is what he has pictured. http://www.ilga.gov/commission/jcar/...ZZ9996deR.html

Never said the pictured trap was right. But you said it was not vented! You can't tell from the picture. What would you do to correct the problem? I think the best/easyest/cheapest would be to extend the piece joining the two 90's at the top of the trap to create a P-trap.

Adding length between the trap 90 and the other one doesn't solve anything. Then, you'll have an S-trap with a longer trap arm.


IF you were only to replace the last 90 with a tee, and have the vent coming right out the top of it, it would still be incorrect as it would then be a crown vent. Here in NC, the distance from the trap weir to the vent has to be 2 times the diameter of the pipe being vented. So in this case it'd need to be at least 4 inches long. But that still wouldn't solve the problem of it being an S-Trap. If you were to swing that 3x2 combo over on it's side, and havce the trap 90 go directly into the side of the 3", it would have a chance of being vented properly assuming that just outside the photo is a vent that's attached before there's too much fall on that pipe. (There used to be a ratio on that sort of thing in NC but I believe it doesn't work anymore.)


But I can tell very easily that currently, that trap's not vented.

Originally Posted by Joshua Hardesty

Adding length between the trap 90 and the other one doesn't solve anything. Then, you'll have an S-trap with a longer trap arm.


IF you were only to replace the last 90 with a tee, and have the vent coming right out the top of it, it would still be incorrect as it would then be a crown vent. Here in NC, the distance from the trap weir to the vent has to be 2 times the diameter of the pipe being vented. So in this case it'd need to be at least 4 inches long. But that still wouldn't solve the problem of it being an S-Trap. If you were to swing that 3x2 combo over on it's side, and havce the trap 90 go directly into the side of the 3", it would have a chance of being vented properly assuming that just outside the photo is a vent that's attached before there's too much fall on that pipe. (There used to be a ratio on that sort of thing in NC but I believe it doesn't work anymore.)


But I can tell very easily that currently, that trap's not vented.

Here in Illinois changing out that last 90 with a tee and making the top of the Tee a vent would make it pass. Think about a lav sink or a kitchen sink. You have the P-trap tyeing into a tee in the wall the top vent is the same diameter as the drain and trap in this case.Some sinks have shallow wells so the tail piece is long like the one here pictured, and I seen where the quarter bend of the P trap as short as a standard street 90 tee into the wall and it only drops into a 2" line about 6 inches below where the tee is in the wall.

So if we go by what your saying a kitchen sink with a 1 1/2" trap will have a 3" vent? As well as the Tube and Lav sink? Now where the vent ties into must be a certain diameter. Here in most cases it is revented into the 4 " stack.

Originally Posted by Ron Hasil

So if we go by what your saying a kitchen sink with a 1 1/2" trap will have a 3" vent? As well as the Tube and Lav sink? Now where the vent ties into must be a certain diameter. Here in most cases it is revented into the 4 " stack.

No, what Joshua is saying is that if you have a vent at the top of the drain above the weir of the trap, it is considered a crown vent.

And, if you move that vent back 1 pipe size from the weir of the trap, you still have a crown vent.

But, if you move that vent back 2 pipe sizes from the weir of the trap, it is no longer acting like, or considered, a crown vent.

Thus, if you have a 1-1/2" trap (kitchen sink), the vent must be 3" ... *back*, not *3" in size*.

That trap in that photo is not vented properly, which includes NOT BEING VENTED. Regardless how you want to argue and state your case, it is not vented "properly" ... vented or not.

That is an 'S' trap, just with a short vertical drop, and not vented properly (if vented at all - no vent is in the photo).

Oh I agree it is a S-Trap as well as it is not vented properly(not all per photo) I said that several posts back. It was just brought up how one would correct this. Illinois code gives a max distance of vent but doesn't state a min distance. Section 885

The only other part about fixture trap vents is that is not to be below the trap weir. Section 890 and http://www.ilga.gov/commission/jcar/...ZZ9996kmR.html

I did miss read about the distance verse pipe size. Its my bad for reading the forums after a 12 hour day doing plumbing repairs.

Ron,

Do you have the link for Illustration L referenced in you second link?

Also see if you have something like this from the IRC.
- P3105.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir.

It may be separate from the distance from the trap to the vent table in that code, just like it is in the IRC.

That code may even have 'crown vent' in the definitions, and should state (someplace in the code) that crown vents are prohibited.

Originally Posted by Jerry Peck

Ron,

Do you have the link for Illustration L referenced in you second link?

Also see if you have something like this from the IRC.
- P3105.3 Crown vent. A vent shall not be installed within two pipe diameters of the trap weir.

It may be separate from the distance from the trap to the vent table in that code, just like it is in the IRC.

That code may even have 'crown vent' in the definitions, and should state (someplace in the code) that crown vents are prohibited.

Here is the Illustration L from Appendix K http://www.ilga.gov/commission/jcar/...ZZ9996klR.html

And now I am more awake and dug out my code book did a bit more reading. I found the part on crown vents. I do wish they group all this information together instead of bouncing it around so much. Here is where what they call a Trap Vent is not allowed with in two pipe diameters of the trap weir. Section 890 and here is the Illustration N it refers to http://www.ilga.gov/commission/jcar/...ZZ9996knR.html I must apologize for being wrong, and thank you all for making me dust off my code book and commit this to memory. I say everyone should keep on learning something new everyday.

This reminded me of back when I did plumbing in Hanover Park , Ill. the inspector there used to come to you ask you about a part in the code, and if you didn't know the answer he handed you the book to look it up and you tell him your interpolation of the code. This guy new the code like a preacher new the bible.

Ron, i'm not sure but think the guy that drew illustration 'L' was even more tired than you? It looks like they are calling the drain trap arm a vent and have it slopped up-hill? Or have I missed something again?

Originally Posted by Vern Heiler

Ron, i'm not sure but think the guy that drew illustration 'L' was even more tired than you? It looks like they are calling the drain trap arm a vent and have it slopped up-hill? Or have I missed something again?

lol, Its just a poor drawing. Does look as its up hill but what they are trying to show is where to messaure from to get the distance to the trap to the vent, and the pitch of the trap. Good catch on that. They should of used the drawing in Illustration M http://www.ilga.gov/commission/jcar/...ZZ9996kmR.html

Now you know what us plumbers have to deal with in these code books. The Chicago code book is even worse.

Here is one from todays inspection. 1 year warranty on 4800 sq ft home. Home owner added a wet bar to the bonus room. Two P traps and some corrugated pipe made it all come together.

He took it well while I explained
- No S traps
- No corrugated pipe
- Must have vent

Bruce,

You know those alarm sensors at the doors to the Big Box stores which detect when an alarmed package goes out unpaid for?

They should hook those up so that when an *DIY idiot* walks through the alarm goes off and warns "STOP - DO NOT PROCEED - SECURITY IDIOT DETECTION HAS JUST DETECTED A DIY IDIOT - TURN AROUND AND GO BACK OUT ... STOP - DO NOT PROCEED - SECURITY IDIOT DETECTION HAS JUST DETECTED A DIY IDIOT - TURN AROUND AND GO BACK OUT ... "

Sadly the hardware stores can sell stuff that do not meet code. I seen plastic S-Trap kits for sale there many of times.. But as a plumber I do love correcting the DIY mistakes.

Never underestimate human intelligence!

Not the trap, but innovative connection for the garage sink.
I just wonder if you need to go to the FORD or CHEVY dealer for replacement parts.

Originally Posted by Fritz Kelly

(didn't read through the posts too carefully) Did anyone mention that it is leaking?

Perhaps because they tried to solvent weld PVC with ABS in a few spots.

Shoulda just used electrical tape and duct tape.

Works better that way!

Originally Posted by Bob Lynett

Anyone ever see this before type of configuration before? Not to mention it is supported with string and rope.

I know alot of folks mentioned not being vented. How does one know for sure? Couldnt that drain into a wet vent that we cant see in the picture? Or does there have to be some visible vent that is next to the trap?

Can someone show me some examples of a picture where the vent is correct because sometimes the main vent stack is behind walls where we cant see it.

It's not necessarily that it's not vented, as we can't see the rest of the pipe. It's that it's

not vented properly. Here's a poorly hand-drawn example of wrong traps:


Anyways, in the photo, the photo on the top is similar to the one in the first picture in this thread. It's an S-Trap, which is defined as a trap whose vent connects below the weir. In this case, if the 3" pipe is vented somewhere we can't see it, it's still improperly vented as it's clearly below the weir.

In the bottom left, let's assume that the distance between the trap weir and the vent is less than 2x the diameter of the trap. This is called crown venting, and is also prohibited.

On the bottom right, the trap arm is longer than what is allowed for the pipe size in that table in the code book. Once the trap arm goes beyond that length, at the minimum required slope, that setup becomes an S-Trap because the vent connects below the weir.

Now, to make a proper vent:

The distance from the weir to the vent must be at least 2x the diameter of the trap, but less than the maximum distance allowed for that pipe size.

The fall on the trap arm must be small enough so that the trap ties in above the weir. (But of course, have at least the minimum slope required for that size pipe.)

Originally Posted by Joshua Hardesty

It's not necessarily that it's not vented, as we can't see the rest of the pipe. It's that it's

not vented properly. Here's a poorly hand-drawn example of wrong traps:


Anyways, in the photo, the photo on the top is similar to the one in the first picture in this thread. It's an S-Trap, which is defined as a trap whose vent connects below the weir. In this case, if the 3" pipe is vented somewhere we can't see it, it's still improperly vented as it's clearly below the weir.

In the bottom left, let's assume that the distance between the trap weir and the vent is less than 2x the diameter of the trap. This is called crown venting, and is also prohibited.

On the bottom right, the trap arm is longer than what is allowed for the pipe size in that table in the code book. Once the trap arm goes beyond that length, at the minimum required slope, that setup becomes an S-Trap because the vent connects below the weir.

Now, to make a proper vent:

The distance from the weir to the vent must be at least 2x the diameter of the trap, but less than the maximum distance allowed for that pipe size.

The fall on the trap arm must be small enough so that the trap ties in above the weir. (But of course, have at least the minimum slope required for that size pipe.)

OK, just to make sure I understand correctly, the trap setup in the bottom left is incorrect or a crown vent because the distance from weir to vent is less than 2X diameter of trap right?

So lets suppose that in that same drawing, we assume that the distance is more than 2X diameter of vent, then it would be a legit vent and trap setup?

Brian,

Here is another drawing of what Joshua was saying.

The left drawing is basically vented at the crown of the trap (kind of like venting an 'S' trap) and is called "crown vented".

If that white space between the trap and the vent is at least 2x the pipe diameter, then the vent is far enough away from the weir of the trap that it will work properly.

However, as Joshua said, with the trap arm sloping downward, if the trap arm is toooooo long, then the vent opening starts below the weir of the trap - as shown in the right drawing - and that is not a good thing either as it will not vent properly like that either.

Between the two limits shown is the correct trap arm length, long enough (2x the pipe diameter) and not too long (the vent is still above the weir of the trap).

With an 'S' trap, which is essentially what that Bob's photo shows, the vent connect in below the weir of the trap - which is not allowed.

This comes up frequently with some saying that is acceptable if the distance between the rise of the 'S' and the fall of the 'S' is long enough, but there is no magic number for that length - it is an 'S' trap regardless. What that length is referring to is the 2x the pipe diameter from the trap weir to the vent ... but the vent must be there.

An 'island vent' is a totally different animal and is designed and constructed totally different, with a "vent" attached at the correct location, only it "vents" back down to the drain line below instead of up to air above.

Joshua, did I explain that properly?

Aye, and with a better photo too. Do you use some kind of software for that?

Joshua,

I have an older version of Paint Shop Pro. It more than serves my purpose, though it is nowhere near as fancy as Adobe Photo Shop.

Corel had (and has) Corel draw, which is believe is similar to Photo Shop, but Corel bought Paint Shop Pro and gussied it all up, making it where it would do great things when in the hands of skilled people - far beyond what I needed (I tried it out for its 30 day free trial and then uninstalled it, I prefer my older Paint Shop Pro 6. I'm just a simple guy, nothing fancy.

Joshua and Jerry, thanks for the pics...they were very helpful. Although I still dont fully understand proper venting to its fullest yet, I know twice as much about it now than I did a couple days ago.

Very appropriate thread for me to see today.
I went to Lowe's today to pick up a few things and what do I see in the plumbing aisle?
'professional grade S-traps' in pvc and chrome
I think we all know that various big box stores sell various items that are not allowed in different municipalities but S-traps?
I would call this another fine example of why we so often find problems in homes. Mr. DIY always figures, 'if they sell it, it must be OK'.

I agree, selling S-traps the way they do is very misleading to a typical DIY'er. They should note that the S-traps they sell should *ONLY* be used to replace existing S-traps installed from a by-gone era, and aren't proper for today's code. But then, they also sell PVC-ABS glue and "bendy-straw" tailpieces, so.. what do I know.

Originally Posted by Joshua Hardesty

They should note that the S-traps they sell should *ONLY* be used to replace existing S-traps installed from a by-gone era,

Should not even be used to replace old 'S' traps.

With AAVs around, there is absolutely NO REASON (other than 'not knowing') to replace an 'S' trap with an 'S' trap. And 'not knowing' is not an acceptable excuse for doing it wrong.

Well, the way I see it I suppose...

Take an old lav with an S-trap running from the sink straight down through the floor before tying into the proper sewer system. Part corrodes, then fails. The person can:

A. Replace it with the same part, making it work just as well (or badly) as it has for the past xx years, or,

B. Cut the old galvanized/cast iron/copper line, transition to PVC/ABS, bring that pipe up through the floor, install a T and an AAV, buy a tubular P-trap, and install it.

Option B, while certainly being the correct way (and the way I'd do it, being a plumber), certainly leaves itself open to even MORE screw-up's to the DIY'er.

True joshua....I would certainly choose the easy option if I were an average DIY'er. Problem is, most average DIY'ers dont even know about proper venting and S traps vs P traps.

I know that a few years ago before I knew about most of that stuff, I would have stuck a new S trap to replace a corroded S trap too. In fact, my wet bar in the basement has an S trap on it. I dont ever smell gas coming out of it though.

Even if I wanted to replace the S trap with a properly vented P trap, I wouldnt know where to begin since the pipe discharges somewhere below a concrete floor.

Either Oatey or Studor, can't remember which, well an AAV kit, where basically, it's a tubular tee fitting, with the AAV on top of it. That way, you can install it between the wall arm of the trap and the trap adapter, and it'll be properly vented. Something like this could be used more easily to fix old S-traps, since they could re-do everything with the tubular plastic fittings, instead of having to redo all the pipes under the floor.

Too bad there's no real way to educate homeowners on such things.

Well Air Admittance Valves are also known as mechanical vents. Which are not allowed at all by Illinois plumbing code. So that would not be an option here. (The red and underlining is done by me.)
Section 890.1480 Types of Fixture Trap Vents

a) Trap Vent. No trap vent shall be installed within two pipe diameters of the trap weir. (See Appendix K: Illustration N.)

b) Common Vent. A common vent, installed vertically, may be used for two fixture traps when both traps connect with a vertical waste at the same level. (See Appendix K: Illustration O.)

c) Vertical Wet Vent. A vertical wet vent may be used for two fixtures set on the same floor level, but connecting at different levels in the stack, provided the vertical drain is one (1) pipe diameter larger than the upper fixture drain and that both drains conform to Appendix A: Table I. (See Appendix K: Illustrations P and Q.)

d) Mechanical Vents. Mechanical devices shall not be installed in lieu of vent piping.

I have had many calls where I had to come in and properly vent bar sinks, or DIY done bathrooms in the basements. Its not all to hard to properly vent a drainage system. Just requires the time and the parts.

The trouble with AAVs is that they only deal with low pressure in the drainage system allowing air to be admitted in to the system. But when there is a high pressure in the system the AAVs stay shut not to allow the foul air to enter the home. Which can cause the trap seal to blow out (gurgling).

Question for Ron:
I had a client call Friday afternoon. PL Contractor told him that the city now allows pvc inground. I've heard this from a couple of other people lately.
It was too late to call the DOB for confirmation. I looked through the code book last night but was unable to find anything.
Do you have any knowledge of this? PVC main lines in ground instead of cast or clay in the basement floor.
Any input would be appreciated.
Thanks, Markus

Originally Posted by Markus Keller

Question for Ron:
I had a client call Friday afternoon. PL Contractor told him that the city now allows pvc inground. I've heard this from a couple of other people lately.
It was too late to call the DOB for confirmation. I looked through the code book last night but was unable to find anything.
Do you have any knowledge of this? PVC main lines in ground instead of cast or clay in the basement floor.
Any input would be appreciated.
Thanks, Markus

I have been told this as well. I do know they allow PVC to be used above ground in Chicago on buildings 3 stories or less. I went through my current Chicago code book and it does not say that PVC is allowed under the home or outside. I also looked in my Chicago Sewer Code book. I am a licensed sewer and drain layer in the city of Chicago as well as a plumber in Illinois. I will call down there Monday, to see if there where any changes to the code since I got both my code books. I post anything I find out for you.

SECTION 401 – CODE MODIFICATION & ADDITIONS

A. Additional Materials accepted in sanitary drainage, waste and vent systems above ground

in buildings three stories or less:

1. Materials ASTM FSS Other Standards

PVC-DWV Schedule 40 pipe D-2665-67 and the Seal

of Approval of the NSF

LP 320a CS272-65

PVC-CWV Fittings D-2665-67 and the Seal

Of Approval of the NSF

LP 320a CS272-65

Solvent Cement D-2564-67 and the Seal

of Approval of the NSF

Thats all I have atm. But will post more later.

I did find this on the Chicago inspection FAQ page for plumbing.

• Q: Are corrugated or stainless steel braided water supply lines allowed in the city?
  
  A: No. They do not meet the pressure rating standard as required by city code.

• Q:Is PVC pipe allowed in the city?
  
  A: Yes, PVC pipe that meets the ASTM standard for plastic piping is allowed in the city, but it can only be used in residential property three stories or less. If the property has any commercial space, then the use of PVC pipe is not allowed.

• On a daily basis, the Plumbing Bureau protects the health of the citizens of Chicago by inspecting and investigating all types of plumbing request that arise from 311 complaints, licensing issues, and permit stops. The Bureau ensures that plumbers have the proper credentials to be performing the work.

• Q: Do you need to be a licensed plumber to perform plumbing work in the city of Chicago?
  
  A: Yes, to perform any plumbing work in Chicago or the State of Illinois a licensed plumber is required. The only exception is for owners of single family homes who are allowed to do their own plumbing work.

Ok I got this out of my 2007 Sewer PErmits, Fees and Standards book. My father has the 2008 and he says it is phrased the same. I will still call the Chicago Sewer and plumbing inspecters to see if there has been any changes not listed in these books.

Pipe Material

Sewers constructed in sizes 21-inches in diameter and smaller must be Extra Strength Clay Pipe,ASTM Designation C-700 with C-425 joints; ductile Iron Pipe, class 52 or equivalent, with push on or mechanical joints; or Cast Iron Pipe, with hot poured pure lead firmly packed with oakum or hemp. (See Section 18-29-702.3 and 18-29-1102.4 of the Municipal Code of Chicago.)

Cast iron pipe cannot be used in the public way.

Cast iron pipe is allowed on private property.

Reinforced Concrete Pipe (R.C.P.) may be used for sewers 24-inches in diameter and larger. ASTM Designation C-76, Class-III, Wall-B with O-ring joints is the minimum requirement for this type of pipe.

No plastic pipe may be used for any underground sewer or drain inside or outside the property, except as specifically allowed by the Municipal Code of Chicago. The Municipal Code of Chicago, Section 18-29-702.3 and 18-29-1102.5, Subsoil Drain Pipe, allows (1) PVC pipe - ASTM D2729 (type Sewer Pipe, PS25, PS50 and PS100); or (2) PVC perforated subsurface drain pipe, ASTM F891 with nylon sock, filter fabric, ASTM D 3034, SDR 35 (4 inch - 15 inch). No corrugated pipe is allowed.

R.C.P. may not be used for pipe 21-inches in diameter and smaller, inside or outside the private property.

If sewer cover is less than three feet (3'-0"), Class 52 or equivalent pressure Ductile Iron Pipe shall be used. If there is less than three feet (3'-0") between the property line of the lot and the building line, the sewer must be relocated or Iron Pipe may be allowed contingent upon review.

Originally Posted by Ron Hasil

Well Air Admittance Valves are also known as mechanical vents.

AAV *ARE NOT* "mechanical vents".

There are other 'somewhat similar' vents being passed off as 'air admittance valves' by some people, and those *ARE* "mechanical vents".

Which are not allowed at all by Illinois plumbing code.

"Mechanical vents" are not allowed in any code, other than for RVs and manufactured homes, because those are built to different standards (not the codes used for regular homes).

So that would not be an option here.

Thus AAVs *would be* an option for you.

The trouble with AAVs is that they only deal with low pressure in the drainage system allowing air to be admitted in to the system.

The standard gravity drainage system *IS* a "low pressure" system, it is not intended to have any pressure in it.

But when there is a high pressure in the system the AAVs stay shut not to allow the foul air to enter the home. Which can cause the trap seal to blow out (gurgling).

Yes, there are "high pressure systems", however, I doubt you will ever see one installed. You could have a combination low pressure system and high pressure system in that the low pressure gravity drainage system drains into an ejector pump which then pumps (high pressure) the waste out through its discharge line. AAVs could be used on the low pressure side of the system (inlet to the holding tank the ejector pump is connected to), but not be allowed on the high pressure side (the discharge piping from the ejector pump).

In a sense studer vents are mechanical as in a spring, a ball and the mechanics operating it is the water going down the drain line pulling it down.

Originally Posted by Jerry Peck

AAV *ARE NOT* "mechanical vents".

There are other 'somewhat similar' vents being passed off as 'air admittance valves' by some people, and those *ARE* "mechanical vents".

Thus AAVs *would be* an option for you.

An AAV is a "valve" which makes it mechanical device. In which it would be and is disallowed in the Illinois plumbing code. I am not arguing with you that an AAV is better than a standard mechanical vent. I seen them at trade shows and understand them 100% Thing is here in Illinois they are not allowed. Other parts of this great country they maybe allowed. Just have to check with you local plumbing codes is all. AS posted above here is the part in the Illinois code again. The bold added by me. d) Mechanical Vents. Mechanical devices shall not be installed in lieu of vent piping.

Originally Posted by Jerry Peck

The standard gravity drainage system *IS* a "low pressure" system, it is not intended to have any pressure in it.

A normal drainage system has high and low pressures in it even with out a pump installed in the system. For example In a two flat home where you have a common sink line serving the second floor kitchen and the first floor kitchen. If the first floor kitchen is not vented, and the second floor sink was filled then let loose there will be a slug of water falling down the vertical pipe which the pressure below the slug is high pressure the pressure above the slug is low pressure. So now since there is no relief vent for the first floor sink it will gurgle breaking the trap seal. I have ran into this many of times both where the re-vent got clogged or the vent was not installed at all.

Joshua,

This is the easy way to correct an 'S' trap with an AAV.

The first question is, how on earth do you make the trap arm longer than the crown of the 'S' trap, and the answer is to angle the 'P' trap away from the vertical leg, then bring it back around to connect into a sanitary tee added to the vertical leg. The trap arm length will be much longer than 2X the pipe diameter as a result of that 'going out, around, and back'.

Originally Posted by Ron Hasil

Jerry Peck in Illinois they still consider a AAV a mechanical device which is not allowed what so ever.

Where does it state that in the code? Not in the part you posted.

No exceptions whatsoever.

It is not an "exception". AAVs are simply not "mechanical traps". And, because they are not "mechanical traps" no "exception" is needed.

Does it "specifically" state that "air admittance valves" are not allowed, or does it specifically state "mechanical traps, such as air admittance valves"?

Originally Posted by Jerry Peck

AAV *ARE NOT* "mechanical vents".

There are other 'somewhat similar' vents being passed off as 'air admittance valves' by some people, and those *ARE* "mechanical vents".



"Mechanical vents" are not allowed in any code, other than for RVs and manufactured homes, because those are built to different standards (not the codes used for regular homes).



Thus AAVs *would be* an option for you.



The standard gravity drainage system *IS* a "low pressure" system, it is not intended to have any pressure in it.



Yes, there are "high pressure systems", however, I doubt you will ever see one installed. You could have a combination low pressure system and high pressure system in that the low pressure gravity drainage system drains into an ejector pump which then pumps (high pressure) the waste out through its discharge line. AAVs could be used on the low pressure side of the system (inlet to the holding tank the ejector pump is connected to), but not be allowed on the high pressure side (the discharge piping from the ejector pump).

Originally Posted by Jerry Peck

Where does it state that in the code? Not in the part you posted.



It is not an "exception". AAVs are simply not "mechanical traps". And, because they are not "mechanical traps" no "exception" is needed.

Does it "specifically" state that "air admittance valves" are not allowed, or does it specifically state "mechanical traps, such as air admittance valves"?

Its not a mechanical trap but it is a mechanical device. Which is not allowed in the code as posted. Take one apart... it is mechanical in nature. They do not want any mechanical vents or devices used in lieu of vent piping. Simple as that. If you want you can call the plumbing department in Springfield Illinois and ask them. They will tell you the same thing I am. AAV's have been covered in my continued education classes every year due to the fact many want to believe they are allowed. The state instructors say different.

Mr. Jerry Peck, I found this link showing which states allow the Studer vents. I hope this clears things up. Studor vents, Studor air admittance valves and air admittance valve caps

Originally Posted by Ted Menelly

In a sense studer vents are mechanical as in a spring, a ball and the mechanics operating it is the water going down the drain line pulling it down.

Air admittance valves are not mechanical in that they *do not have* those things to make them operate.

Ted and Ron,

http://www.psdmagazine.com/ASPE_memb...CodeUpdate.pdf

"

The dictionary defines a mechanical device as a “mechanism consisting of a device that works on mechanical principles.” The dictionary also states that a mechanism is “an assembly of moving parts performing a complete functional motion, often being part of a large machine.” By these definitions, an air admittance valve is not a mechanical device; however, it does have a moving part functioning via gravity that prevents sewer gases from escaping from the drainage system.

"

Originally Posted by Ron Hasil

Mr. Jerry Peck, I found this link showing which states allow the Studer vents. I hope this clears things up. Studor vents, Studor air admittance valves and air admittance valve caps

Ron,

Not really as that does not post the code which prohibits air admittance valves, which are not "mechanical vents".

Originally Posted by Jerry Peck

Ron,

Not really as that does not post the code which prohibits air admittance valves, which are not "mechanical vents".

I have posted the part of the code many times. An AAV is a mechanical device is it not? In the Illinois pluming code Section 890.1480 Types of Fixture Trap Vents it states in part (d) d) Mechanical Vents. Mechanical devices shall not be installed in lieu of vent piping.

So by that definition alone it is not allowed. Sadly the Illinois code books of today just tell us what is allowed and not allowed. They do not tell us why like the older code books I own from the 50's and older. Also here is the link from Studor's web site and not a reseller. STUDOR (R) inVENTive Technology (TM) - Air Admittance Valves It shows as I stated It is allowed in some states, and not allowed in others, like Illinois.

Here is some parts from individual villages that are in the Chicagoland area.

This is from the City of Elmhurst codes which they publish to help clarify some issues in the Illinois Code as well to be stricter. Here is the link to the PDF for their amendments : http://www.elmhurst.org/elmhurst/bui...anual/tab4.pdf

20. PLUMBING/Materials – Not Permitted

The following are not permitted:
a. Air Admittance Valves
b. CPVC Pipe
c. Foam core – PVC pipe with cellular core

d. Type M copper

Jerry: In that photo, the original S-trap would be the same diameter as a tubular p-trap from today, right? Being significantly smaller than the 1.5" galvanized pipe it empties into. The AAV's I've used are meant to fix onto 1.5" pvc (or 3".. but who the heck needs one of THOSE suckers under a sink?), so they wouldn't be able to attach like that. Furthermore, I've never seen a tubular sanitary tee that I could replace the lower S-bend with. Not saying they don't exist, just never seen them.


Ron:

So, how do you guys vent things that we'd use studors on? Island venting? I know very little about island vents because I've never had to use them, but I thought they were limited to being used pretty much only on islands. If that's the case, how do you vent a kitchen sink that's underneath a window? Do you simply not put the window right there, or do you build an extra-thick wall that lets you run 1.5 or 2" pipe through it?

Originally Posted by Joshua Hardesty

Ron:

So, how do you guys vent things that we'd use studors on? Island venting? I know very little about island vents because I've never had to use them, but I thought they were limited to being used pretty much only on islands. If that's the case, how do you vent a kitchen sink that's underneath a window? Do you simply not put the window right there, or do you build an extra-thick wall that lets you run 1.5 or 2" pipe through it?

If the sink is against the window you just offset the vent. You could have the drain offset as well. here is a couple pictures that shows what I mean. Also a picture demonstrating an island vent. The last pic I added the black lines for the drain and the green is the vent.

Originally Posted by Ron Hasil

I have posted the part of the code many times.

Actually, you have not, but I see you finally posted on cities code on it below. That is what I have been asking for you to do.

An AAV is a mechanical device is it not?

I answered that question in a previous post above, and, no, it is not.

In the Illinois pluming code Section 890.1480 Types of Fixture Trap Vents it states in part (d) d) Mechanical Vents. Mechanical devices shall not be installed in lieu of vent piping.

So by that definition alone it is not allowed.

No, by definition, it is 'not not allowed' (with the double negative of 'not not' canceling out and with it being allowed, because, by definition, an AAV is not a mechanical vent).

Also here is the link from Studor's web site and not a reseller. STUDOR (R) inVENTive Technology (TM) - Air Admittance Valves It shows as I stated It is allowed in some states, and not allowed in others, like Illinois.

I read that, but that is not a code stating AAVs are not allowed, it is only a listing of AHJ stating it is not allowed.

That is two different things. 'Code stating it is not allowed' is different than 'AHJ stating it is not allowed'.

To give an example of that is the change in AHJ 'not requiring sediment traps in Texas' and those same AHJ now changing their mind and 'requiring sediment traps'. THE CODE did not change, just the opinion of the AHJ.

20. PLUMBING/Materials – Not Permitted

The following are not permitted:
a. Air Admittance Valves
b. CPVC Pipe
c. Foam core – PVC pipe with cellular core

d. Type M copper

Finally, a code stating what I had been asking you to provide. However, now, what about the other cities and towns? What about Chicago itself?

AHJ stating they are not allowed to be used is not the same as the code stating they are not allowed to be used. The two may have the same effect, but the AHJ can wise up and change their mind, while the code is the code is the code ... and ... the code says what the code says ... regardless of how the AHJ reads it. You have to follow the AHJ, but it has been shown *many times* where the AHJ is wrong, and, sometimes, the AHJ will acknowledge it and change their ways.

On to your photos now, if I understand what you are saying, when an 'S' trap is corrected, all that drywall/plaster/whatever has to be ripped out, the wall framing cut up, and than a vent installed?

No wonder the plumbers don't want AAVs allowed ... a simple $100 job now becomes a $2,000+ job.

Ron, thanks for listing some of the info. It's only been 10-12 years at the most I think that pvc has been allowed at all, can't be more than 15 though. I remember 4" pvc has only been allowed for around 5-7 years.
I can't really imagine that the city has allowed pvc inground but the idea seems to be going around. I'm also going to call the DOB tomorrow we'll see what kind of answers we both get.
I'm foggy on the details but I remember at some point AAV's not being allowed in small res but being allowed in older mid-rise and high-rise buildings. I've been through a number of mid & high rise buildings where every kitchen has an AAV in the 4th SS sink hole. This is not an issue I have kept up on though.

Ron: Yeah, in my area we're not allowed to bore that large of a hole through a 2x4 stud like that.

Jerry, the State of Illinois considers AAVs as a mechanical device. It has a moving part that can and will fail, So it is not allowed. Again I am sorry if the Illinois code does not name them by name. That is why some cities found the need to print amendments clarifying the state code that they are not allowed. I will contact the Springfield Public Health Department to get some sort of clarification for you. About correcting an S trap. If the sink was installed to code there would never been an S trap installed. I have Illinois code books that go back to 1938 and S traps where never allowed. So if a home owner was a DIY or hired a handyman to install a sink and they used a S trap its their own fault. Which is sad but yes they may have to spend a few bucks to correct the issue.

Joshua, those photo's are not from around here. But to drill the hole we are required to reinforce the 2x4 stud when we drill the hole.

Markus, I talked to a couple of my Chicago licensed plumbers they believe plastic is not allowed underground for the building drain or building sewer still. But they are not 100% positive. So tomorrow morning I call down there and ask. It would be great if they allow SDR plastic pipe for the building sewers. I hate working with that clay pipe. On the AAVs you saw did they look like the photo below? If so those where Air Gaps for the dishwasher discharge.

Jerry Peck, here is another part of the Illinois plumbing code, that would not allow an AAV to be used in place of vent piping. Bold and underlining done by me.

Section 890.1420 Stack Vents, Vent Stacks, Main Vents

a) Design. A properly designed and installed venting system, in conjunction with the soil or waste system, is essential to protect trap seals and prevent siphonage, aspiration, or back pressure. The venting system shall be designed and installed to permit the admission or emission of air so that under normal and intended use the seal of any fixture trap shall never be subjected to a pneumatic pressure differential of more than a one (1) inch water column. If a trap seal is subject to loss by evaporation, means shall be provided to prevent loss of the trap seal. (See Section 890.410(f).)

As I stated an AAV only allows air to enter (low pressure) the system, it does not deal with emission (high pressure) of air.

Ron,

Key words in your quote "venting SYSTEM". I've changed the bold and underlining highlighting to show that.

That is precisely why EVERY "venting SYSTEM" on which AAVs are installed are *required* to "have at least one vent which go to outdoors and opens to atmosphere".

Originally Posted by Ron Hasil

Section 890.1420 Stack Vents, Vent Stacks, Main Vents

a) Design. A properly designed and installed venting system, in conjunction with the soil or waste system, is essential to protect trap seals and prevent siphon age, aspiration, or back pressure. The venting system shall be designed and installed to permit the admission or emission of air so that under normal and intended use the seal of any fixture trap shall never be subjected to a pneumatic pressure differential of more than a one (1) inch water column. If a trap seal is subject to loss by evaporation, means shall be provided to prevent loss of the trap seal. (See Section 890.410(f).)

As you will note, it does not say "vent", it says "venting SYSTEM".

As I stated an AAV only allows air to enter (low pressure) the system, it does not deal with emission (high pressure) of air.

As stated above, an individual AAV on an individual vent is not "The venting system" ... unless there is but one fixture and one vent, in which case the AAVs requirements are that "at least one vent which go to outdoors and opens to atmosphere" - which simply means you are not allowed to install an AAV on a single fixture "system" which has only one vent.

Originally Posted by Jerry Peck

Ron,

Finally, a code stating what I had been asking you to provide. However, now, what about the other cities and towns? What about Chicago itself?

Jerry, seems no matter what I point out to you. You want to poke holes into the plumbing code of Illinois. I have stated 1000 times that Illinois does not allow AAV's, they (Illinois) considers them to be a mechanical device(something with a moving part that can fail). In Illinois a venting system consist of a main vent, re-vents, circuit vents, relief vents and branch vents. Not a AAV in lieu of any of these vents as stated in the the code I posted numerous times.

I have stated if you had a system where you had a sink on the second floor draining full force down a common sink line with a sink attached to it on the first floor, with out a proper vent, it would gurgle. An AAV is not a proper vent it will not deal with the high pressure from the water slug traveling down the sink line.