Bathroom renovation and need to move vent that goes up through the roof. I will need to elbow it under the floor to go through the adjoining wall about 1 ft. away and then go up into the attic and elbow it back to the section that passes through the roof. Would that be a problem at all? It's all ABS right now, do I have to stay with ABS? If joining can it be glued or only use Fernco splices?
Relocating vent and Joining ABS to PVC??
- Thread starter Eman85
- Start date
wwhitney
In the Trades
Your horizontal vent offset is fine if it is located at least 6" above the flood rim(s) of the fixture(s) vented.
You could stick with ABS, or switch to PVC. Easiest way to join the dissimilar materials is a shielded rubber coupling, e.g. Mission BandSeal or Fernco Proflex (not the exposed rubber Ferncos that are only for underground use). Depending on what rework you need to do, those shielded rubber couplings can also be helpful even for like to like materials, e.g. because you don't have clearance to slide a piece of pipe into a hub for a solvent weld connection.
Cheers, Wayne
You could stick with ABS, or switch to PVC. Easiest way to join the dissimilar materials is a shielded rubber coupling, e.g. Mission BandSeal or Fernco Proflex (not the exposed rubber Ferncos that are only for underground use). Depending on what rework you need to do, those shielded rubber couplings can also be helpful even for like to like materials, e.g. because you don't have clearance to slide a piece of pipe into a hub for a solvent weld connection.
Cheers, Wayne
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Not exactly sure what you mean. My plumbing is under the floor and that's where I need to go horizontal then vertical then horizontal back to vertical. The first horizontal will be above the drain line it is plumbed into by about 8".
Only reason for the PVC to ABS is PVC I can get 2 mi from my home, ABS is 25 mi.
wwhitney
In the Trades
A dry vent needs to come off of the trap arm vertically (at least 45 degrees above horizontal) and stay vertical until at least 6" above the fixture flood rim.
If you need to shift horizontally below that elevation, can you do it while still rising vertically at 45 degrees? That's the only code compliant option for a dry vent.
Cheers, Wayne
If you need to shift horizontally below that elevation, can you do it while still rising vertically at 45 degrees? That's the only code compliant option for a dry vent.
Cheers, Wayne
wwhitney
In the Trades
Trap arm means the fixture drain between the exit of the trap (trap weir) and the point where the vent is connected. It is limited in fall to one trap diameter (2" for your 2" trap) so that the vent can do its job of preventing the trap from siphoning. That in turn provides a length limit, which would be at most 8' for a 2" trap (minimum fall is 1/4" per foot), but some plumbing codes impose a shorter length limit.
You absolutely can use a horizontal long turn 90 on the trap arm, or after the vent takeoff, to arrange to have the trap arm run to a suitable location for the vent takeoff. Some plumbing codes allow a regular quarter bend on a trap arm, but the LT90 is always a better choice.
Cheers, Wayne
You absolutely can use a horizontal long turn 90 on the trap arm, or after the vent takeoff, to arrange to have the trap arm run to a suitable location for the vent takeoff. Some plumbing codes allow a regular quarter bend on a trap arm, but the LT90 is always a better choice.
Cheers, Wayne
I tried to load my pics of what I have now but it said the file was too large.
The trap arm was about 12" to a tee. The bottom of the tee had an elbow which connected to the drain line. The upper exit of the tee went straight up through the roof as a vent.
I can use a 45* on the drain line and get to the correct spot to duplicate what I have and the trap arm would be less than 2'. The vent would then go straight up about 9' before needing an elbow to get to the roof exit.
Thanks for the info.
The trap arm was about 12" to a tee. The bottom of the tee had an elbow which connected to the drain line. The upper exit of the tee went straight up through the roof as a vent.
I can use a 45* on the drain line and get to the correct spot to duplicate what I have and the trap arm would be less than 2'. The vent would then go straight up about 9' before needing an elbow to get to the roof exit.
Thanks for the info.
wwhitney
In the Trades
Master Plumber Mark
Sensitivity trainer and plumber of mens souls
ABS and PVC glue together just fine..... I have had to do it many times and being a vent it is not even an issue
If you are worried about it just go buy a can of pvc glue that is specifically made to join these plastics together for
probably 15 bucks... but any normal glue will actually do the job just fine
If you are worried about it just go buy a can of pvc glue that is specifically made to join these plastics together for
probably 15 bucks... but any normal glue will actually do the job just fine
While green transition cement can join ABS and PVC successfully and reliably, and UPC is happy with it, oddly IPC is not.
codes.iccsafe.org
There have been proposals to change IPC on this.
CHAPTER 7 SANITARY DRAINAGE - 2021 INTERNATIONAL PLUMBING CODE (IPC)
ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.
codes.iccsafe.org
There have been proposals to change IPC on this.
Master Plumber Mark
Sensitivity trainer and plumber of mens souls
While green transition cement can join ABS and PVC successfully and reliably, and UPC is happy with it, oddly IPC is not.
CHAPTER 7 SANITARY DRAINAGE - 2021 INTERNATIONAL PLUMBING CODE (IPC)
ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.
There have been proposals to change IPC on this.
They all work just fine.... so maybe the glue will fail in 275 years instead of 500 years
who is gonna be around to file a complaint???
I'm not a plumber, just a handyman homeowner. I have seen PVC joined to ABS and read about how it's only allowed at the transition from the home to the septic line. I didn't think it would be a problem on a vent but rather know what's right.
If I remember correctly PVC must be primed but you don't use primer on ABS, is that correct?
FWIW there is no inspector, permits or anyone going look at this, it's my home.
If I remember correctly PVC must be primed but you don't use primer on ABS, is that correct?
FWIW there is no inspector, permits or anyone going look at this, it's my home.
Sounds good. Now suppose you have an ABS pipe. You will attach a PVC coupling, and cement PVC pipe into the other end of the coupling.
I have not found clear/consistent answers to these:
1. Use green transition cement for both joints, or just the ABS-to-PVC transition?
2. If you use green transition cement for both sides, apply primer to the PVC pipe but not the ABS pipe, or use no primer at all?
I have not found clear/consistent answers to these:
1. Use green transition cement for both joints, or just the ABS-to-PVC transition?
2. If you use green transition cement for both sides, apply primer to the PVC pipe but not the ABS pipe, or use no primer at all?
Crawled under and as expected plans fell apart. I have an HVAC duct in the way that I need to address first.
I did see a diagram of a vent and they rolled a tee 45* to have the vent pipe move to where they wanted and then used a 45* to send it vertical.
I did see a diagram of a vent and they rolled a tee 45* to have the vent pipe move to where they wanted and then used a 45* to send it vertical.
wwhitney
In the Trades
That's fine, TN is apparently on the IPC, so you could use a san-tee on its back for such a vent takeoff. If you have room for a combo, it would be slightly better (my plumbing code, the UPC, would require the combo).
Another option is to use a wye for the vent takeoff and roll it up 45 degrees. That actually puts your vent takeoff at 30 degrees above horizontal, so you'd need a 60 degree bend to turn up to vertical. The vent takeoff is technically not vertical, but if it's just a few feet and to get around obstructions, it is commonly accepted.
Cheers, Wayne
Master Plumber Mark
Sensitivity trainer and plumber of mens souls
What size vent are you planning on installing..>>>??? If this is not the main vent for the home I would suggest Just throwing an auto air vent on that line and forget about it.....
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