1950 Wet vent remodel options?

[Russell Harris]

Hello,
I have a 1952 cast iron drain setup for a hall bath that uses a wet vent from the lavatory for the tub. In the picture below, you can see that the lav drain runs about 3ft back towards the tub then turns back into the 2" drain that is running from the tub. The cast iron is failing and weeping on the lav and I'd like to replace with PVC, plus raise the drain from the tub up off the dirt.
My question is do I need to recreate the 3' run back towards the tub for the lav drain? Or can I just raise everything and have the lav drop into a wye right at the good 2" cast iron before it goes into the 4"? Does the run back towards the tub somehow make the wet vent better?

Thanks for any advice!
RH

 

[James Henry]

I can't tell if this will work for you with the space constraints but this is a proper wet vent.

 

[Sponsor]

 

[JohnnyCom]

Looks like the jog back towards the tub may be there to keep the tub trap arm under the maximum 5 feet per UPC.

 

[Russell Harris]

Looks like the jog back towards the tub may be there to keep the tub trap arm under the maximum 5 feet per UPC.

Johnnycom you are correct that the distance from the lav to the tub drain is greater than 5'. Probably 7' or so. I guess also in 1952 they had sections of cast iron premade and that's just what they used. Also here in Austin its the UPC still.

James Henry, thanks for the drawing. Sounds like I might have a distance issue to compensate for but I think I can basically do what you have if I can get that 5' maximum. I do have a gas line oh so conveniently placed right in my way. One question on the 45 degree vertical drop where everything ties back in. Can it be greater? Like 60 degrees or maybe 70?

Thanks everyone for the input!
RH

 

[James Henry]

One question on the 45 degree vertical drop where everything ties back in. Can it be greater? Like 60 degrees or maybe 70?

Any angle you like.