[Our_Old_House]

Mark,

Somehow I thought you needed one AAV per appliance. Today after sending you the last answer, I began studying AAVs and found that is not true. I’ve tried to copy a solution I found in an AAV manufacturer brochure and using that information redid a diagram using one AAV. As you stated it is an easy straight forward solution. Please take a look. It is a lot easier and less costly than building soffits.

Thanks in advance.

Lonny

[massplumber2008]

If you run the toilet vent and connect that into the existing vent and then run the washing machine vent into the existing vent then you are really in good shape here. The shower should also be able to bevented in the same manner... just take the vent off the top and run that in with all the other vents above the floor.

The individual vent for the kitchen sink is great, but remember the AAV will work real nice under the sink here so may not be necessary to run that vent up and out the roof... although it would, of course, be the best job!

The AAV for the pedestal is good!

MARK

[Our_Old_House]

I'm not sure I understood what you said. I think you said the Washing Machine and Toilet was okay. You lost me on the shower. Can the shower and the sink be vented by the AAV as I showed in my drawing?

[massplumber2008]

Hi Lonny:

Venting the shower using the AAV off the pedestal sink is an improvement to an unvented shower STRAP, for sure, but the shower would still be considered unvented. Here, if an STRAP remains, it is an unvented fixture... vent must come above the PTRAP.

You would need to add an AAV in the crawlspace (so it is 6 inches above the trap (up in the joist bay) OR pipe it up as I show in red in the drawing below... see image.

Let me know if that is more clear...

MARK

[Our_Old_House]

Mark,

I am continuing to make progress on the bathroom. The new "level" subfloor is in, new recessed lights are installed, and the remaining electrical has been stubbed out. Executing our plumbing plan is underway. However, I have an issue with the plumbing of the pedestal sink. Because the plumbing will be visible on a pedestal sink we are using brushed nickel supply, drain lines, and stops. This makes installing an AAV between the P-Trap and wall a problem due to both the way it looks and the amount of room between the wall and the sink drain center (8 ½”). Is it acceptable to place the AAV below the floor in the crawl space? I’ve included a diagram showing our original plan and hopefully an alternative.

Suggestions would be greatly appreciated.

Thanks,

Lonny

[massplumber2008]

Hey Lonny

The AAV is supposed to go at least 4" above the Ptrap...simply not legal plumbing today if done any other way...*OUCH*! Best result would come from installing the AAV inside the wall with an access panel for the future (could even be just behind the mirror).

However, that being stated to free me up of any guilt...:cool:...you could pipe the 1.5" PVC ptrap and the AAV in the crawlspace with the trap at about 6 inches below the floor... the AAV would come out of the ptrap and run up close to the floor boards. Then you can run a straight shot of 1.25" tubular drain pipe from the sink drain assembly (plastic or metal as it won't be seen inside the pedestal base) through the floor and connect into the 1.5" PVC using an 1.5" PVC x 1.25" trap adapter at the PTRAP.

I don't like this option but it was used for a long time way back when and it was better than no vent at all!

Back to you...

MARK

PS: Check to be sure that you have a straight shot from the sink drain down through the pedestal base. If you don't you may need to use a diamond saw to cut some of the bottom of the base...let me know.

[Our_Old_House]

Mark,

Thanks for getting back to me. I cannot take the drain through the pedestal due to the pedestal mounting bolt directly below the sink drain. Putting the AAV behind the mirror is a good option. There are electrical wires in that location, but that should not be a big problem. Because the mirror is oval and side mounts, so that it can be tilted, it is about 1 1/2" away from the wall. I now need to convince my wife that you will not be able to see the AAV access panel.

After a lot of thought regarding the subfloor I decided not to use a self leveling compound to level the floor. The house's pier and beams are on clay and there is a small amount of movement between wet winter and dry summers and I was concerned that the self leveling compound would breakup over time. Therefore I laid down a 15# felt vapor barrier on the tong and grove subfloor, then roofing shingles to get a good level, then ¾” T & G plywood screwed down on a 6” grid. The floor is now level with no movement. I hope this solution will hold up over time.

I better get back to work. Thanks for your help.

Lonny

[massplumber2008]

Hi Lonny:

The vent behind the mirror is definitely the best choice!

In terms of the floor, I think you should be fine. I've done the same many times over the years... ;)

Keep me posted.

MARK

[Our_Old_House]

Hi Mark,

I am now working under the house connecting all the plumbing. I have a short distance, about 3 feet or less from the toilet to the horizontal (with at least a ¼” drop per foot) main drain. Is it acceptable to run the closet bend horizontal with no drop for about 3 feet? The distance is so short I am having a problem finding any fitting that doesn’t drop too fast to match the main sewer drain. I’ve attach a drawing, but it is difficult to draw in 3 dimensions.

Thanks again for your help

Post Edit

I've edited this post and added an alternative that gives me rotation in 3 axises. Let me know what you think. Thanks

Post Edit 2

Simplified the Sewer Connection Diagram by elimating the Long 90 and the Wye and replaced them with a Combination Y- 1/8. Again let me know what you think.

Lonny

[massplumber2008]

Hi Lonny... see my thoughts on this in RED below... ;)

MARK