Change in direction of washer trap arm

[DanFL]

Hi All,

I opened up this wall for a renovation and found this washer trap does not meet the minimum height above floor. This is on a second floor. Am I allowed to raise the trap by adding the 45 bends as shown in the photo (IPC)? Washer rough-in box also needs to be raised. In case it's relevant, the upper trap arm is for a bathroom sink on the other side of the wall.

Thanks,
Dan

 

[Reach4]

No.
The good news is, AFAIK, no minimum height above the floor for you under IPC.

Of more concern is whether that vertical wet vent of the laundry standpipe is OK. I think it is, but I am not sure.

 

[Sponsor]

 

[wwhitney]

Of more concern is whether that vertical wet vent of the laundry standpipe is OK. I think it is, but I am not sure.

IPC allows the "common venting of two fixtures connected at different levels". So as long as the pipe above the sink san-tee is a dry vent with nothing draining down, the configuration is OK.

The IPC allows the standpipe to be 18" to 42" above the trap weir, so that should suffice for raising the washer box as long as you don't go too high.

Cheers, Wayne

 

[Terry]

You can't use 45's to raise the trap. The trap arm gets a 2% grade.

 

[DanFL]

Thanks for all the quick replies, you guys are always really helpful. I can confirm that the vent above the sink san-tee is a dry vent. Just for my own education, what is the "physics" reason for the 6" min trap height above the floor (for UPC), since Reach4 suggested it is not a requirement for IPC?

 

[Terry]

UPC mandates that a washing machine P-trap must be between 6–18 inches above floor level. In most cases, it is illegal to plumb a washing machine P-trap that does not conform to UPC standards. An incorrectly installed P-trap can vent dangerous sewer gas into your home.

I sometimes wondered if having the requirement made the p-trap visible too. I have seen them left out, letting sewer gas into the home.
"My laundry room always has a funky smell.' Un Huh

I was helping a friend cooking dinner, hanging by the kitchen sink, and OMG, it did not smell good even though what we were making was wonderful. As part of her kitchen remodel, they had installed one of the new deep sinks, and since this was a 60's home, and the drain was too high in the wall, they had left the p-trap off. The next day I opened up the wall, lowered the drain, and installed a p-trap. The kitchen now smelled like how a kitchen should smell when cooking.

 

[Reach4]

While I don't know the reason, I suspect they had in mind the height they wanted for the top of the standpipe. Then given the length of the standpipe, that would cause the opening to be at a good height. I am picturing them allowing that he who installs the sanitary tee may not be the one who installs the standpipe. No, neither of those would be really good reasons, but they are the best I could come up with.

Canada allows the standpipe trap to be below floor level. Still works.