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Review DWV design request

1K views 8 replies 3 participants last post by  Ghostmaker 
#1 ·
So I purchased a plumbing permit from King County, WA for my bathroom project and the website says that entitles me to have an inspector review my plans. But my inspector says they don't do that --- rough it in and they'll come take a look. Having never done a DWV system before, I'm wondering if someone could take a look at the plan I created. I hate to rough it in only to have to rip it out and start over.
 

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#2 ·
If you have followed King Co. wet vent criteria, you are good for the most part. But I got a couple questions/comments:

Are you required to have the shower vent? It's okay to have it there,but may not be needed- the 2" vent on the lav may be sufficient. Again, verify with King CO wet vent code section.
If you keep both vents- the lav vent may be 1.5" until it meets with the shower/toilet vent. At that point 2" is required
I'd move the 3" cleanout to the end by the shower. (end of the line)
Will your inspector allow the ABS section in the cast iron or will he want cast iron pipe in that section?
Most of this can be answered by your inspector or King Co code
 
#3 ·
The wet vent sample I found did not have a vent on the shower, I just included that because it would be easy to do. So I really could drop it and just do 2" for the lav. For the cleanout on the 3", I was thinking the same thing. The lav and shower are above the basement wall, but I think I'll still have room to just put it at the end.

Good question on the ABS. So I guess what I could do there would be to cut out a section out of the iron for the wye and just keep the iron, but would I need to even tackle that prior to the leak inspection? This is my first DWV project so that's something I don't know. Maybe they will want the fitting on the existing 3" but have the fitting plugged and then plug the new line in front of that for the test? I suppose it depends on the inspector.
 
#6 ·
You can rent a ratchet style soil pipe cutter designed to cut cast iron.
Or buy several saw-zall blades to cut it. A 3rd option that I use often is a small grinder with a cut off wheel. This requires 360* access though. With option 2 & 3 besure to use hand and eye protection.
Updated design with 1 vent and cleanout moved. I will see if the inspector will answer the question on the wet vent just to verify and replacing the cast iron section with ABS. Thanks for the comments.
Most inspectors I have dealt with allow the ABS tie in. Some don't like it.
Use "Proseal" PLxCI shielded couplings at the transition- normal rubber (Fernco) are not approved indoors.

Helpful tip- cut out the CI section first. Then add the filler pipe to proper length. If you make up the new section first and then attempt to cut out a matching section you only get one shot at cutting it square and to proper length...
 
#7 ·
Thanks again for the tips - much appreciated! Hopefully the ABS will be ok. The tie in to the existing 3" is the one part that worries me. The place where I want to tie in is downline from the existing bathroom, so as I think about it, it seems like I might have to disassemble it back to that bathroom, then build it back, in which case I'll end up replacing all the cast iron that is upline from the tie-in for the new BR.
 
#8 ·
When I made tie-ins like this, I allowed for my fitting with about 4" of pipe out both ends.
Then I would cut that much out of the cast. Then confirm my cut measurement to my plastic piece before I glued it up- just in case I missed on the cut and had to lengthen a piece in the fitting.
I allowed a 1/2" for the proseal couplings(1/4") each each of the ABS.

BTW- only 3 toilets are allowed on a 3" line
 
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