DWV System: Do you guys see anything wrong?

[JohnnyR]

Well I've decided to take on the task of doing my own DWV system, and thought I'd run it by you guys first. I'm in Spokane, WA and we are currently under UPC. I submitted my plan to the building dept. and they approved it, but it was also a 2 dimensional drawing. Here's some shots of what I've come up with. What do you think?







Am I correct in assuming the 90's in the drainage part of the system should be long turns?

I also have a San Tee on its back but it's in the vent part of the system, should I still use a wye-1/8 combo there as well or is the san tee alright?

And lastly, is it necessary to have a clean out on the vent line like the drain line next to it?(bottom/middle pic 3)

I know you'll probably need a little more info, this is my first thread so fire away

Thank you in advance

JohnnyR

Helpful Plumbing Hints for Residential Construction by Bert Polk Plumbing Inspector Lincoln County

 

[Jc60618]

1.The code I follow allows me to use sanitary tee's for venting.
2.Long sweep 90's are not required for horizontal to vertical only for vertical to horizontal.
3.It wouldnt hurt to add a clean out on the vent line.

Finally the sanitary tees on the vertical vent line would normally be installed up side down.

 

[Sponsor]

 

[JohnnyR]

Thanks for the response JC. I really appreciate it. So what youre saying is that the SAN TEE is flowing up, towards the roof exit of the vent?

Thanks again

 

[Jimbo]

The UPC says this: "Where vents connect to a horizontal drainage pipe, each vent pipe shall have its invert taken off above the drainage centerline..." and it adds that " Vents less than 6" above the flood level rim of the fixture shall be installed with approved drainage fittings"

 

[JohnnyR]

Hey Jimbo

Thanks for the response, If I'm reading that correctly, i wouldnt be able to use a san tee in that spot because its less than 6" above the flood level. That vent is for the floor drain.

 

[hj]

That "floor drain" vent is completely worthless as shown. It does NOT vent the floor drain line, and would not unless it were attached to the floor drain line BEFORE it connected to the tub/shower drain. The one at the top of that line is backwards, however. What is that yellow vent line from downstairs for? Right now it looks like it is just "cosmetic".

 

[JohnnyR]

Hey HJ

See, thats why I asked you guys, cause the Building Dept. didnt say anything about it lol. But in their defence, I didn't show them a 3d model either. So are you saying I should just eliminate the "floor drain" vent:



The vent going to the basement would be for the floor drain in the basement. Sorry I didnt include that in the sketch.

As for the top san tee being backwards, ya just noticed that too. Coming to Spokane anytime soon hahaha.

 

[Asktom]

The "floor drain" needs to be vented before tying into the washing machine drain line. Also,it looks like you are tying into the floor drain vent in the basement, that won't pass muster. You need to connect downstream from where the vent comes off the basement floor drain line (assuming it is large enough to handle the added fixture units, otherwise you will need to find a different point of connection).

 

[JohnnyR]

Thanks Tom

I was scared of the that, I also agree with you that, that is the basement floor drain vent. I do have another drain downstream from that vent so, I'll have to rework that part. As for the Laundry room floor drain and stack, what do you think of this configuration?



I made the mistake of assuming what was there before was right. ei: tying into the basement floor drain vent. Thats what I get for assuming.

 

[Nukeman]

That won't work either because now you have a flat vent (less than 45* angle before getting 6" above flood rim) on the floor drain.

If you did like the 1st drawing, it could work if you brought that vent line (circled) and connected to the arm of the floor drain (before it hits the wye).

If UPC allows for a "combination drain and vent system", you may have some additional options on how to run it.

 

[JohnnyR]

Ahhh, gotcha thanks nukeman, that makes sense. Thank you for the response. You guys are great!

 

[Asktom]

The tee at the bottom of the circled section needs to be a combination rather than a sand tee. If you are fighting height on the "floor drain", use the circled section as the WM drain and out the back of the combination at the bottom put a 45 looking up, into the 45 glue a san tee with the branch turned horizonal and a 45 in the top of the san tee turned vertical for the vent. You can put a 45 in the branch of the san tee to angle toward the "floor drain".

 

[JohnnyR]

Hey Tom

Thanks again, am I reading you right? If so brilliant, Here's what I think you're trying to say....

 

[Krow]

Why don't you wet vent the floor drain with the washing machine drain. You will have one less vent to worry about

 

[JohnnyR]

Hey Krow

I was under the impression I couldn't.

 

[Krow]

I know I can in my area, I'm not sure about Spokane

I don't know about your area, but I would use a 3" branch(not code but, just to be safe) from your FD line to wet vent. Place it as far maximum as allowed in your area from the FD. (some places its 5' , some places 6')

 

[Asktom]

Yes, that is what I meant. If you put the male end of a street 45 in the bottom of the san tee you could save a bit more height. I am guessing you have that line same line pass over the top of the vent before it drops into the wye for structural reasons, if not, you could offset the vent over the drain instead and save even more inches. If you need to go over the vent, use a 1/6 bend to drop into the wye in order to come off at 90 degrees.

I assume you are under some permutaion of the UPC in Spokane and can't wet vent the "floor drain" through the WM drain. It would be simpler, but I would ask the inspector first.

 

[Asktom]

Oops, I suppose I should proofread before I hit the submit button, not after. Got an extra "line" in there, hope you can follow my drift.

 

[Asktom]

Another oops, you don't need to come up at a 45 for the floor drain unless you are downstream from the washing machine. If the floor drain is the last fixture on the branch you can put a combination on its back with the vent going up and the trap arm run into the end.

 

[hj]

That's right, you can't because the washer's velocity could aspirate the trap. Why are you fixated on running the floor drain at an angle. Use a y-1/8 bend for the vent and connect the floor drain into the end of it with an elbow turning to the drain's location. The only way that vent would work for the lower floor drain is if it is connected TO the floor drain's pipe. Having a vent "near" a drain does not make it a vent FOR that drain.