Failed inspection! Advice?

[GatorKenD]

Here's updated drawing. BA #2 does have a shower and sink and I added them to this drawing. I also added vent stacks (red dots) based on their location on the roof (I have a flat roof house so that was easy to place). 3" stack between the toilets, 2" behind the master bathroom sink. Given that the inspector can't know what's in the walls or under the slab, was it reasonable to assume the bathroom was wet vented and fail the washer drain?

 

[Tom Sawyer]

Both toilets the tub, and the shower appear to be wet vented and as running your new washer would cause waste to flow past and thereby obstruct the vent, you inspector is indeed correct. You will have to find a way to route the new fixtures past that vent stack. And you will still need to individually vent the washer and laundry sink. That will require moving the washer drain to a point above the floor.

 

[Sponsor]

 

[hj]

That cleanout is deep enough that the ENTIRE bathroom probably drops into it and it wet vents NOTHING. Any "wet vents" would be above the floor level, and would have NOTHING to do with anything attached to the cleanout area. My impression is that your inspector used to work at Home Depot but got fired because he did not meet their standards for an "aisle assistance" worker.

 

[hj]

quote; Both toilets the tub, and the shower appear to be wet vented and as running your new washer would cause waste to flow past and thereby obstruct the ven

You may have a misconception about "wet vents" because it would have to be a very weird installation for anything to be using the main line for a wet vent.

 

[hj]

The vents SHOULD rise up from the toilets, the tub and shower, and the sink, the pass through the roof, meaning NONE of them are wet vented through the main line and there is absolutely NO WAY the washer flow could obstruct the vent.

 

[Tom Sawyer]

Sorry my friend but it is you that needs to refresh your understanding of wet venting.

 

[hj]

Maybe YOU could provide a picture of HOW you think that bathroom group could be wet vented. I think I outdate you by many years and have probably installed hundreds more systems with "proper" wet vents.

 

[Tom Sawyer]

There's nothing weird about it at all. That lateral is probably 3" and runs directly beneath and parallel to the wall above. Both toilets are on a double wye and the stack runs vertically off the lateral and is buried in the wet wall. The shower and tub both wye into the 3" and are wet vented through the stack. The 2nd bath lav most likely has its own vent that ties back into the stack also. The master bath has its own vent. The clean out comes off the end of the 3" lateral. Dumping the washer in there would block off the vent when the washer dumps. The tub and shower are wet vented because the lateral receives waste from both toilets.

This is my fortieth year as a licensed master plumber and my 23rd as a certified license renewal seminar provider.

 

[GatorKenD]

more info: measured from outside, the top of the 4" cleanout (not 3") is 19" below the top of the slab (most likely ~4" slab).

Does that support a position either way? While I don't want to tear up the slab (the plumber told me that's what the inspector said was necessary to convince him), I am planning on eventually remodelling these bathrooms so tearing holes in the wall would be tolerable. Is there something I could find in the walls that would support EVERYTHING having been dry vented?

 

[Tom Sawyer]

3" 4" makes no difference.

 

[hj]

A camera inserted through the cleanout would show if there was a single opening between the two toilets and one at the tub and shower, and MAYBE a third one for the sink, ALL of them on the top of the pipe. If TS is correct, and our inspectors might have a problem with it, there will be multiple openings on the sides at these locations. IF he is correct, and the tub shower does connect in to the 3", then they are "unvented" because his scenario has the vertical vent between them and the toilets, making it "cosmetic" as far as they are concerned and the toilet flow past their connections CAN cause siphonage.

 

[hj]

With his scenario, the cleanout could be 8" below the slab and still work.

 

[Tom Sawyer]

A camera inserted through the cleanout would show if there was a single opening between the two toilets and one at the tub and shower, and MAYBE a third one for the sink, ALL of them on the top of the pipe. If TS is correct, and our inspectors might have a problem with it, there will be multiple openings on the sides at these locations. IF he is correct, and the tub shower does connect in to the 3", then they are "unvented" because his scenario has the vertical vent between them and the toilets, making it "cosmetic" as far as they are concerned and the toilet flow past their connections CAN cause siphonage.

No, if done and sized correctly they are wet vented through the stack. You don't have to dump another fixture into the stack to make it a wet vent. The wet vent portion would be the horizontal that is sized so that there is air movement over the upper section of the pipe on the theory that the pipe is never completely full and contrary to popular and past thought, even toilets won't fill the pipe. For many years it was felt that the toilet had to discharge below the vertical portion of the wet vent stack but that notion has been disproven, especially with low flow fixtures in use today.

Anyhow..... You are going to have to break up the floor and wye off after the bathrooms.

 

[hj]

quote; he wet vent portion would be the horizontal that is sized so that there is air movement over the upper section

That is a "combination waste and vent system" and is governed by very specific regulations.

 

[hj]

HE is already connected AFTER the bathrooms. The inspector, such as he is, wants it BEFORE the bathrooms.

"Inspector came out today and said we cannot put a washing machine drain upstream of the bathrooms."

 

[Tom Sawyer]

O

HE is already connected AFTER the bathrooms. The inspector, such as he is, wants it BEFORE the bathrooms.

Ok, I can see where that's confusing so what I meant was downstream of the bathrooms. That after. Yes also, a combination waste and vent is closely tied to wet venting in that the same principles apply.

 

[Terry]

Back to back UPC

Master

And a few more

 

[Tom Sawyer]

There you go. I tried to pull the ISO's off the IPC but couldn't figure how to get them to post. They are just about the exact same as what you posted. IPC would let you put the toilets anywhere on the branch. Thanks.

 

[Tom Sawyer]

Keep in mind that any additional fixtures outside of the wet vent that are to be drained into the same branch must be connected to the branch downstream of the wet vent. Because the wet vent serves as a drain, the type of fittings used must be in accordance with the drainage pattern shown in Table 706.3 of the IPC.

 

[hj]

You have to be kidding! That is a lot of , and mataerial, on the toilets to avoid using a combo and double fixture fitting with a vertical vent. I have NEVER installed back to back toilets that way, but have used ingenuity when the sewer has to be close to the floor line.