Please check my work

[Brooke Stabbert]

Hi, I’m building a new backyard cottage in Seattle (UPC) and would like a check on the drain line runs I’ve put together. I extended the 4” pvc main sewer line from the house under permit from city of Seattle. The cottage will have a full bath, washing machine, and kitchen sink.

I swapped from pvc to abs when the line turns into the cottage, mating with a fernco strong back. Then the line turns up to 45 degree angle. I have three lines connecting into that 3” that is rising at 45 degrees. The first is the 2” coming from the shower, lav, and washer. Each of those has its own 2” dry vent before they merge together. I then have that line transition from horizontal (with 1/4” fall) to vertical via a long 90 that goes straight down into the vertical arm of a Y coming off the 3” drain. Is that ok? I am assuming since this is after all vents, I can turn it down like this to drop into the main line.

I’m doing the same for the toilet line as well. It is running horizontal (5’), gets vented vertically (combo sweep to a vert 2” dry) and then I have it turn down to drop vertically into the Y arm coming off the main drain.

Finally, the 2” drain coming from the kitchen flows directly into the raised end of the 3” drain. It is a 24’ run with 1/4/ft fall and clean outs in the middle and far end.

 

[Brooke Stabbert]

Here is the tub drain run. It has to pass through a joist and then turn 90 before getting to the vent (total arm length under 3’) so I put a combo on its side to allow a clean out (plug missing in photo).

And here is the shower run on the other side of passing through the blocking along with the toilet run in the neighboring joist bay. Please note that these connections are dry fit now and the “wobble” in the toilet line will be corrected with glue up.

 

[Sponsor]

 

[Brooke Stabbert]

Here is the lav and washer run inside.

And this is the vent takeoff for the toilet. It connects to the lav/washer vent above the ceiling level.

Here is the tub vent. It is a straight run up through the roof. It jogs 22 degrees off vertical as is passes through the sill plate to avoid the 4x10 that underpins that wall (same with the lab/washer vent).

 

[Brooke Stabbert]

Here is the kitchen sink run. Vent does the same 22 degree jog going through the sill plate to miss the 4x10 below it.

And here is the kitchen drain under the floor with clean out where it turns horizontal to run 24’ with a 6” drop to the main drain with another clean out half way along the run. Please ignore the missing coupling. Again, this is all dry fit right now.

 

[Brooke Stabbert]

So I have three 2” vents (tub, lav/washer, kitchen) through the roof to meet the code requiring equivalent area to the 3” drain.

What have I missed? What have I got wrong?

Thanks in advance!

 

[Tuttles Revenge]

This all looks very diligently installed.

The laundry and kitchen require cleanouts. If those are underneath then disregard, tho I prefer to install them above the trap arm so the drain can be used while snaking (however you'll never need any of the cleanouts since you're all ABS/PVC). Obviously you'll need more hangers. Every 48" on ABS. You'll need a 3" end of the line cleanout for the toilet run.

A couple nitpicky things that don't matter but an inspector will call out.
The vent tee above the clothes washer is "upside down". It should slope upwards towards the roof.
OK.. that's only 1 nitpicky thing.

looks really good.

As a side note on cross sectional venting. Assuming you have a typical house built in the 1920 like almost all Seattle homes, then it has at least one 4" through the roof. That meets the cross sectional for the house. It also meets cross sectional for any other building on that property, so you only need to meet the DFU requirements in the ADU, not the cross sectional of the 3" leaving the building. You could have installed just one 2" thru the roof there. But more isn't bad.

 

[wwhitney]

The vent tee above the clothes washer is "upside down". It should slope upwards towards the roof.

I'm going to say that doesn't actually matter, as the air will still make it out. I.e. I don't think there's a clearcut UPC code violation that can be cited.

On the OPs, I agree it looks very good. Just one question:

I swapped from pvc to abs when the line turns into the cottage, mating with a fernco strong back.

Looking at the first picture, that appears to be the wrong fitting and not a Fernco Strongback. Of course I may be mistaken because it it hard to tell from a picture. If it's actually a Fernco Strongback, the fitting will be just over 4" long, and have (4) total hose clamps to tighten: (2) at the ends as usual on a Fernco, and (2) more just inside of those, for the additional shield that is used on the Strongback.

If the fitting is just over 2" long and has just (2) hose clamps, as it appears to me, that's a regular Fernco Proflex / Mission Rubber BandSeal fitting, which are only listed for use above ground, and it should be changed.

Cheers, Wayne

 

[Tuttles Revenge]

I'm going to say that doesn't actually matter, as the air will still make it out. I.e. I don't think there's a clearcut UPC code violation that can be cited.

On the OPs, I agree it looks very good. Just one question:

Yeah, it will get flagged in Seattle if the inspector sees it. Even if it creates zero air flow issues they consider that since it turns downward its obstructing the full size of the venting, even if its oversized. And since its not glued yet its easy to place in the direction of flow and not have to cut out glued work.

 

[Brooke Stabbert]

I am very appreciative of your input. I’m in process of gluing up now. I’m incorporating your input as I do so. I’ll flip the SaniTee on the upper section of the washer vent. I’ll add a clean out in the line above where the Lav drops in.

For the toilet clean out can I just replace the 90 elbow the flange connects to with a combi Y and use the butt end for the clean out?

 

[Brooke Stabbert]

Wayne is correct that my pvc to abs 4” connector is a proflex and NOT actually a strong back. I’ve ordered up a strong back to replace it. Good catch! Thank you.

 

[Brooke Stabbert]

Tuttles - noted on the roof vent cumulative area. I sssumed the city would look at the cottage as a standalone. No big difference in this project though as it would likely only have gotten down to two roof vents instead of three (could have connected tub vent to kav/washer/toilet vent).

 

[Jeff H Young]

Nice work , I caught the wrongly installed san tee as well didnt know whether to mention it or not had really only beesn skimming over the details .
Ive only worked in UPC and no one would ever plumb it that way intentionally Ive seen it befor and Ive seen toilets vented 1 1/2" befor totally wrong but pretty harmless somebody screwed up it hapens like on a wet vent someone might put a 2x2x1 1/2 san tee I seen it when I did production work . in practice the santee wouldnt hurt and If I was an inspector Id sign card but tell guy to fix it on the honor system rather than re test the entire system. and waste a trip out.
Thanks for showing your job Brooke !!

 

[Brooke Stabbert]

Does this work for my toilet line clean out with a plug in the heel?

Is there a required distance behind the clean out for access? There is only 13” between that heel and the row of blocking in the joist bay. I can extend it through the blocking if I need to.

 

[wwhitney]

UPC 707 covers cleanouts, and 707.9 covers access. 707.9 requires 18" clearance for 3" pipes, but I suggest reading all of UPC 707, as I'm not that familiar with it.

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Cheers, Wayne

 

[Brooke Stabbert]

Wayne - thanks, I’ll review those sections.

Here is the corrected lav/washer stack with corrected sanitee and clean out. Also added the stud shoes for the bores over 2 1/8”.

 

[wwhitney]

Just to double check, UPC has some particular requirements on the standpipe for the clothes washers, see UPC 804.1:

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Also, it looks like your standpipe receptor is about 32" above the finish floor level? That's probably fine, but it bears double checking the minimum height above the floor that is specified in the manual for your washing machine.

Cheers, Wayne

 

[Brooke Stabbert]

Wayne - yes, the washer trap wier is about 10” (more than 6” and less than 18) and the standpipe is between 18”-30” above the wier.

Well be using a compact stacked washer dryer stack that this layout work for. It requires a discharge height between 24”-40”.

 

[Jeff H Young]

Wayne actually a good point on the wash machine box height, Browsing install manuals i found one that requires 39 inch minimum and that includes if dumping in a sink, a lot of 39 inch tall laundry sinks around LOL . some but not all tell you put a siphon break on and no min height required on stand pipe.
So yea we can meet UPC code but not be able to legaly install a machine due to meeting manufacture instructions. first Ive ever seen that. Something else to worry about LOL a builder/ owner supplys us with the appliance cut sheets and I suppose its our responceability to be sure to read every word of the installation instructions befor starting work.

 

[Tuttles Revenge]

I wouldn't install the Cleanout on the combo like that, The back side of it will fill up with poo.

Rather a WYE downstream of the toilet 90. I generally like to extend the cleanout to point where it can be accessed easily. But really you'll never need to use it since all your drains and sewer are modern
plastic.

Wayne actually a good point on the wash machine box height, Browsing install manuals i found one that requires 39 inch minimum and that includes if dumping in a sink, a lot of 39 inch tall laundry sinks around LOL . some but not all tell you put a siphon break on and no min height required on stand pipe.

We had one washing machine box that was set about 5ft off the ground. The manufacture of the clothes washer said that as long as the hose would reach, their machine would pump. Inspector wasn't buying it tho, but since it was a secondary clothes washer he passed it. (basically didn't want to continue to argue with me)

 

[Jeff H Young]

96 inches 8 foot high standpipe above floor passes manufacture specs on many machines. wont pass UPC but an example where I think it should is if there is a horizontal drain line say 3 foot or 5 foot off the floor what in the world would be so wrong with having a box up high the minimum stand pipe height and max imum might have reasons like suds or siponing the trap but the trap needing to be a certain distance off floor seems to have no sensible reason a trap 3 ft off floor with minimum stand pipe length should not be an issue. I cant say I understand all the thinking on codes or agree on UPC code in regards to this.
I didnt mention but agree with tuttles on the clean out as well , Ive allways felt it would collect stuff there i didnt really have knowledge it does but I have suspected it would but havent seen clean outs there very often. I just dont like it .