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EFS

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is this OK?

main_stack_vent_02_reduced.jpg
 

MTcummins

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No. There is a reason vents are the size they are. Your plumber reducing vent lines like this and your other post is not something they should be doing, or any inspector should be approving.
 

EFS

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I guessed so by now... what are my options? Ask the inspector to come back and have a closer look?
 

Tom Sawyer

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Is that the only vent in the home? IPC calls for one vent that is half the size of the building drain which in most cases is going to be 1 1/2" to vent through the roof so it may well be to code.
 

EFS

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this the vent from the main stack (which is 4 inches) and it is suppose to combine with other vents (from individual fixtures) in the attic so one vent will go through the roof.

My concern is whether the vent can be reduced in size on its way upas shown on the picture?
 

MTcummins

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Is that the only vent in the home? IPC calls for one vent that is half the size of the building drain which in most cases is going to be 1 1/2" to vent through the roof so it may well be to code.

Huh? 1.5" isn't enough to vent even 1 toilet. Pretty sure you need at least an equal total area of venting as drainage, so for a 4" stack, you need a 4" vent, or a 3" and a 2" (I think, not looking at the equivalents right now), or some other combination. Also, I don't think you're allowed to reduce a vent like that... maybe if the total venting load on the line is less than the allowable fixture units for a 1.5" vent, but again, that wouldn't even allow there to be a toilet on this line.
 

Geniescience

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post size of vent and whether this is the only vent.

efs, please add detail.

In other web forums I have read that one of your two vent stacks has been cut off from the outside and turned into an AAV. This might be serious.

key words for web search to find other threads about your problems:
lazypup efs vent stack
"... stack is serving only the kitchen and laundry, and they will both be fitted with AAV's, therefore the stack is now only a vertical portion of a vented branch and it does not require a vent."

and another thread
lazypup efs bathroom
 

Jimbo

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Since you are in country where it snows, they may not allow ANY 2" vent thru the roof.....that is so small it can potenially be snowed over
 

EFS

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I have two stacks in the basement. One was (and will be when the addition is done) serving toilets and all bathrooms (2.5) and this is the stack vent on the picture (i.e. the one that was reduced by the plumber to 1.5, maybe 2 I had not measured). My understanding of the code was that the vent size cannot be reduced, hence posting this picture and asking plumbers who know the code for clarification.

My second stack was serving one kitchen sink and laundry sink and will be serving 2 kitchen sinks (first floor) and one laundry sink in the basement. That stack has been running with 2” (? maybe 3” vent- I had not measured it exactly- it is an old cast iron venting pipe) that has been cut during re-roofing and the plumber has no intention of re-building that vent and told me they will vent both kitchen sinks with AAV (on the individual sinks) and the entire stack with AAV on the stack (in the basement).

We were not happy with that solution, but were told that inspector has approved that proposition. The inspector had not seen the vent reduction shown on the above picture. All other fixtures are vented individually and the vents are suppose to meet in the attick and have one commont roof exit.

I also have a vent pipe of 2" that is reduced to 1.5" shown on the pictures in my "masterbath" plumbing post- somebody picked it up but the picture was not clear, but I checked it and the vent size is reduced going up, i.e. I have two fixtures vented with 2" pipe merging with two additional vent pipes of 1.5' each and then reduced to 1.5 " vent going into the attick - is this per code?

Yes, we have snow- I ami n CT.
 

hj

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WE do NOT know how your code is written. In your area it may state that you need a ""full size pipe from the sewer connection out through the roof. Or it may say that the "total" AREA, (not diameters), of the vents through the roof must equal the area, (NOT THE DIAMETER), of the incoming pipe, but from the appearance of that vent it conforms to NEITHER requirement. In fact, in many "freezing" areas, the pipe, regardless of its size has to be INCREASED one pipe size, (but a minimum of 4" pipe), from 12" below the roof to its temination above the roof. If you were in Chicago or Arizona, I could tell you which rule applies.
 
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MTcummins

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There is no way, in any part of the country, that what you have described is legal. Your plumber and inspector are both doing you a huge disservice.

Find a highly reputable plumber in the area and have them come do a full inspection of this. From what I've seen so far, there are probably far more errors, or at best lots of bad practice stuff (like all those fittings on your water supply lines).

You absolutely cannot have the stack just cut off in the attic... it will need to be taken back through the roof, or taken over and tied in with the main stack vent. This vent will likely need to be 3" or 4" through the roof, depending on your local code. We get decent snow here in Pittsburgh, and are allowed 3" if the stack is 3". If its 4" stack, we'd require either a 4" through roof, or a 3" and a 2", or some other combination, as jimbo said, to get the same area venting as the total drain stack capacity. If you have 2 stacks, you will almost certainly need 4" if they let you go through roof with just 1 vent.

The 1.5" or 2" reduction is a joke.
 

Tom Sawyer

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Huh? 1.5" isn't enough to vent even 1 toilet. Pretty sure you need at least an equal total area of venting as drainage, so for a 4" stack, you need a 4" vent, or a 3" and a 2" (I think, not looking at the equivalents right now), or some other combination. Also, I don't think you're allowed to reduce a vent like that... maybe if the total venting load on the line is less than the allowable fixture units for a 1.5" vent, but again, that wouldn't even allow there to be a toilet on this line.

If your code is the IPC you need to read section 9. You only need one vent that is half the size of the building drain through the roof and furthermore the distance from water closet to vent is listed as "unlimited" with no size requirement. And BTW technically toilets do not need to be vented as they are a full siphoning, self vented fixture.
 

MTcummins

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I stand by my recommendation to get a REAL plumber to come check all of this out. Whoever did this mess is a hack, even if they're licensed.

There's no way what the OP described is legal under ANY plumbing code. There are fittings in his pictures that are illegal. No doubt the venting is all wrong too. You know you're tradesmen are screwing you when they cut off a stack in the attic so they don't have to flash around it. What a crock that is.

I don't know what Tom is talking about, we don't use IPC, but if what he's saying is true, don't follow IPC. Those requirements are a joke, and definitely will cause problems in your area. I'm fairly certain neither the IRC or the IBC will allow anything he said. You want a minimum of a 3" vent, you do not want all those AAVs (if the old system was vented, why the heck would they take them out and put in AAVs? Thats ridiculous and not at all acceptable if there is a way to vent them properly), you certainly don't want an AAV in the attic on the top of a stack, the list goes on.
 

Tom Sawyer

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I stand by my recommendation to get a REAL plumber to come check all of this out. Whoever did this mess is a hack, even if they're licensed.

There's no way what the OP described is legal under ANY plumbing code. There are fittings in his pictures that are illegal. No doubt the venting is all wrong too. You know you're tradesmen are screwing you when they cut off a stack in the attic so they don't have to flash around it. What a crock that is.

I don't know what Tom is talking about, we don't use IPC, but if what he's saying is true, don't follow IPC. Those requirements are a joke, and definitely will cause problems in your area. I'm fairly certain neither the IRC or the IBC will allow anything he said. You want a minimum of a 3" vent, you do not want all those AAVs (if the old system was vented, why the heck would they take them out and put in AAVs? Thats ridiculous and not at all acceptable if there is a way to vent them properly), you certainly don't want an AAV in the attic on the top of a stack, the list goes on.

If PA is using the IPC he kind of has to follow it. I don't want to get into it with you but really you need to do a little more reading before you start typing. Though the IPC has some issues (and EVERY code has issues) there is absolutely no reason why a residence (unless it's a 50 room mansion) should ever need 3 and 4 inch venting. Look at your vent/dfu charts and do the math. A single 1 1/2" vent will vent two bath room groups just fine. Roof penetration should be 3" minimum if you are in a frost zone and where I live it needs to be 4" but we can and do tie the other smaller vents into the roof penetration. BTW the IRC and the IPC are essentially the same code where the plumbing is concerned.
 

EFS

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the reduction shown on the picture is from 4" to 1.5".. This is an extension of the main waste stack. This particular waste stack collects waste on the second floor from one toilet and in the basements gets waste from all the other fixtures as listed below (which are all individually vented except for the toilet on the second floor). I have 3 toilets (12 DFUs), 1 bidet (1 DFU) 5 lavatory (5 DFUs), 2 showers (6 DFUs as one is a double head shower), laundry sink (2 DFUs), washing machine (2 DFUs) and 1 bathtub (2DFUs) draining to this stack (30 DFUs if my assignments and math are correct). I have a secondary stack (that I was told is really a vertical branch) with AAV on it that drains: 3 sinks (additional 6 DFUs). So my house drain system is 36 DFUs. Based on what is below, my guess is I need 4" stack and at minimum 2" vent for that stack.

Here are some details from CT code:

SECTION 903 VENT STACKS AND STACK VENTS

(section 903.1 from the code)

Every building in which plumbing is installed shall have at least one stack the size of which is not less than one-half of the required size of the building drain. Such stack shall run undiminished in size and as directly as possible from the building drain through to the open air or to a vent header that extends to the open air.

(section 910):

" WASTE STACK VENT.

(...)910.1 The waste stack shall be vertical, and both horizontal and vertical offsets shall be prohibited.

A stack vent shall be provided for the waste stack. The size of the stack vent shall be equal to the size of the waste stack.... '' (this is my highlighting how does this refers to “..not less than one-half of the required size of the building drain”)

The waste stack shall be sized based on the total discharge to the stack and the discharge within a branch interval in accordance with Table 910.4. The waste stack shall be the same size throughout its length.

The Table 910.4 WASTE STACK VENT SIZE says:

stack size (in inches) Maximum number of DFU total discharge for stack

2” 4
2.5” 8
3” 24
 

Tom Sawyer

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That's not a waste stack vent so that does not apply. reducing vent size is never recommended however, it appears that you are indeed under the IPC so that is probably why the plumber did that and the inspector approved it.
 

EFS

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what is it then if not a waste stack vent? There is no other vent for the stack. The inspector had not seen this one.

I think that the code is dictating a "minimum" and there are also "best practices" which may dictate work that is better just because it works better and it is beyond the minimum of the code requirements. I think this is the issue here…
 
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