Hello,
I need to complete properly the venting on my house. This is the current setup, which has no venting on none of the fixtures. Could you please recommend (in drawing if at all possible) how to finish the rest of it? Thank you

Attached is a drawing of all the current piping.

Link: http://sworld01.com/_wizardimages/House/Drain-Vent.jpg

Hi Mutly.. glad to help on this, but first you need to find out if wet venting is allowed in your area, OK? Simply stated, wet venting saves time and money so let's hope it's allowed in your area. Call a local plumbing inspector and ask... let me know what he says.

No matter what venting system we use here, know that all the sinks and the lavatories need individual vents. The washer will also require an individual vent. All vents will connect together and connect into the vent stack at a minimum of 42" off the finish floor. To tell you more I need to know the answer to the wet venting question and I also need to know the pipe size of all sinks/lavatories, OK?

Back to you...

Mark

Mark's bang on. Every code going mandates that every fixture that has a trap MUST be vented. You fall woefully short of that. If wet vents are allowed some can be and others must have their own.
Follow Marks advice and you'll be just fine. Good luck, Tom PS. Nice isometric!

Thank you Mark for your response. I am not sure about the code allowing the wet venting, but I suspect that they do. In any way, could you please direct me both ways? (Scenario 1 and 2 if they don't). All of my pipes leading to all fixtures are 2" but I plan to convert to 1 1/2" leading from wall to them. As well I plan to connect the vent pipes to the vent stack under the roof.

Thanks Tom as well.

David

Hey Dave,

In any way, could you please direct me both ways? (Scenario 1 and 2 if they don't). Sure, Mark could do both but why put him through the trouble when all it would take is one phone call to your Building Department to learn if wet venting's allowed in your area?

I plan to convert to 1 1/2" leading from wall to them. As well I plan to connect the vent pipes to the vent stack under the roof. There's a down side tom combining all the vents in the attic and just having one vent pipe exiting the roof.
Sure you can hide the roof vent in the back and have a nice clean roof line facing the street. But that comes with a price if you ever have a blockage that can only be reached from a roof vent.
The plumber has to haul his sewer machine, cables and equipment up in the attic, locate the correct vent and cut into the pipe. He then has to set his equipment up and snake the vent. Afterwards he has to couple the pipe back together and get out of there.
All this while dragging his sewer machine and rolls of cable through your home after they're all covered with slimy black gunk.
This involves a increase in time and labor. And who do you thinks going to pay for that. I don't know of any plumber that doesn't cringe when he known he has to clime up in the attic and the heat of the summer and clear a clog. I know I don't! I just thought I'd keep you informed. Let Mark know about the wet vents. Good luck on your project, Tomk

Hey Tom,

Thanks for your input, I will definitely consider all the pros and cons as well as the future needs. Regarding the code, I asked two plumber companies about the code if they knew, since it's Saturday and I cannot reach anyone at the city, and they do not even know what a wet vent is.

Why I asked for both options was because I may consider the better option even if the wet vent is allowed. I just do not know what would it entail. Once I see it on a paper, I can tell if it's worth the effort. In any way, even if it is only one drawing from Mark, I'd still appreciate it to a great extent.

Why I asked for both options was because I may consider the better option even if the wet vent is allowed. I just do not know what would it entails.
It's a no brainer, Therer is no better option the wet venting unless you wish to pay through the nose for more materials and labor. They both will work but not being able to wet vent will cost you more. Make the call and hope you can tell Mark to draw you up a set of drainage plans that have wet vents. Regards, Tom

Ok, so the code is the same as for the FL state. Wet venting is allowed. Please advise... David

Mark, wet venting is allowed and the size is 2" to the wall for ALL fixtures. From the wall I will use 1 1/2" to all lavatories and sinks (from wall 2"). Bathtub/shower and washer will have 2". Thank you in advance for your time and help. David

Hi David...

OK, I drew this up... see below.

First, notice that I added three toilet vents (by themselves). Two toilets are unvented and I can't see a way to wet vent them with the fixtures as you drew this up so you need to add a 2" vent to each. The other toilet has a washing machine between the toilet and the sink and since you can't use a washing machine drain/vent as a wet vent you need to add another 2" vent for this toilet.

Next, for the other vents that are acting as wet vents the drain and vent MUST be 2" all the way to the vent stack.

The 1.5" vents are individual vents and can be piped 1.5" as shown.

Vents pitch from the vent stack to the fixtures so any rain water that gets down the stack can flow down the vent via gravity to the drain system.

All vent fittings are installed so, again, rain water can flow by gravity into the drain system...here, basically, vent fittings get inverted as drawn below.

2" for washing machine drain is best, but you can install an 1.5" vent.

Hang all pipes every 4 feet.

Install full-size cleanouts under all kitchen sinks and if possible before any pipes go into the ground... if possible.

Back to you...

Mark

Thank you Mark,

One more question. Is there a minimum height code for the pipes to connect to the vent stack? The front part I want to connect to the stack well before ceilings and the back portion (Washer, etc) via roof. I will be using 2" pipes for venting. Is there anything else you'd recommend? David

So nobody can second guess you, connect any vent a MINIMUM of 45" off the finish floor.

Mark

Hey Mark,

I am attaching a finalized drawing of the whole project with more details. Could you please double check and point out to me any mistakes or issues with the layout? Green is for 4" pipes. The rest is 2" (Red is for venting). Again thank you so much for your advice. David

http://sworld01.com/_wizardimages/House/Design-01.jpg

Marks busy but I see a few issues that should be changed.
1) You're using the washer for a wet vent on the sink. Connect the washer to the main by itself.
2) Your vanity (V) has a "S"trap. Move the vent over to connect to the trap.
3) wye off the main to pick up the tub where the WC will be wet vented by it.

Wow! You've gone from no vents to venting everything but the family dog.
Mark will be along shortly to check this out. As he mentioned. Roll all vents coming directly off the main on a 45 degree angle at the connection. Good luck, Tom

Thank you Tom.

Is this all right?

http://sworld01.com/_wizardimages/House/Design-02.jpg

Hi Mutley...

I'll look this over tomorrow sometime and let you know what I think, OK?

Mark

Thank you Mark, take your time, no rush.

Hi Mutley...

Check out the drawing below. I removed a couple vents you had marked.. see drawing. Where the vents were removed you should be using the sink vent to vent the sink and toilet at the 1/2 bath and the sink, tub and toilet at the other bathroom? I also extended the vent and emphasized a WYE connection into the toilet drain at the full bath. You are using wyes for these connections into the waste piping, right? Remember, no sanitary tee fittings on waste lines (unless a VENT ONLY).

Then, please revise your drawing in the area circled below... it is unclear exactly how all this connects together, OK?

Finally, after you revise your drawing, I'll calculate the vent sizing to be sure you don't need to bump one part of the vent system up a size... ;)

Thanks...

Mark

Hello Mark,

Thank you. I have made changes according to yours and changed a little the detail part. There are arrows where there are connections, otherwise the pipes just overlap in the drawing.

http://sworld01.com/_wizardimages/House/Design-03b.jpg

http://sworld01.com/_wizardimages/House/Design-03-db.jpg

Mutley...

You cannot use Tee fittings (also called sanitary tee fitting) in horizontal drain lines... must be WYE fittings.

You can use a sanitary tee fitting ONLY if the fitting goes to a vent exclusively...

The 4x4x4 tee fittings you show need to be wyes fittings, but you also can't pipe these up so pipes cross into each other like you have. Here, drainage has direction... all must drain down, not across fittings and then back down the drain, you know?

Redraw all this using WYE fittings for the drains. Any wet vented fittings need to be wyes, too. Only use a sanitary tee fitting on the vertical (to pick up a sink, for example) or if you are installing an individual vent for a fixture.

Check out my revised drawing of one section below... should give you an idea of proper connections into the main drain. I know a lot of this is existing, but don't forget the cleanouts, OK?

Back to you...

Mark

Mark,

I double checked and all the connections are WYE's not TEE's. I don't know why they looked to me more like a T than Y shaped. Phew!. I got scared there for a minute.

Anyway, so you know what I am up against, please see attached layout of the fixtures and let me know if there is anything else I can do to simplify the piping or how would you do it. I am all ears on suggestions and advice as I DO want to be up to code and I want to plan this with future in mind or possible re-sale. Thank you.

http://sworld01.com/_wizardimages/House/Layout.jpg

http://sworld01.com/_wizardimages/House/Layout.jpg

Is it OK to have two roof vents on one system? One as the main vent 4" pipe (seen in the picture) and the other only 2" pipe on the other end (right above the washer)? But they both connect to the same system. Or do I have to run it all across and connect the 2" to the 4" main pipe? I want to save the on the materials, time and labor and not to mention it is much easier to just make an opening it the roof. The distance is like 24 feet apart through the attic. Thanks

Hi Mutley1

No problem putting the 2" through the roof separately.

Mark

Mark, I got to say many thanks for all your help. I had finished the whole project a while back and left the small vent unfinished just under the roof as I had other things to do, and I thought it may be a good thing to leave it separate. By the way all is perfect and working like a charm, didn't have any issues at all with leaks, not even a drop!

I have one more question: The 2" vent, can I run NEXT to it a dryer vent and cup it with the same vent cover?

I'm afraid I didn't understand that last question... at least in terms of "cup it with the same vent cover"... what does that mean?

I know I would keep the washer vent away from the dryer vent just in case you get a backdraft down the dryer vent... could bring sewer gasses in with it, you know?

Back to you...

Mark

What I meant was to put two pipes next to each other and come out from the same hole in the roof and cover them with one vent cover. But you are right, there may be a back draft, I didn't think of that. So I don't think that's a good idea, now.

I agree... :)

Glad things are going well!