I need advice on what to do with this 1-1/2" vent.
Some background. The primary bath was remodeled about 15 years ago -- before I owned the house. In the process, the old shower area now has the toilet room. To service the toilet, a new 2" vent was run as in the diagram. It runs up into the attic, turns 90 degrees, then lays flat on the trusses for about 4 feet, turns 90 degrees (still flat) and the another 4 feet until it turns up and exits the roof. My roof has concrete tiles. The 2" vent is sloped fine and the total horizontal run in the attic is probably 8 feet total.
In the process, they abandoned the old 1-1/2" shower vent. But, rather than fix the roof penetration, they just capped off the bottom of the vent pipe and left it hanging from the friction of the roof collar. Well, you know how well that worked. I found this pipe laying on its side in the attic with daylight coming in the roof penetration. Fortunately, I'm in a dry climate and no one ever noticed this in 15 years!
I'd rather not fix the roof penetration and I stuck the pipe back up through the flashing collar. This won't last once the capped off pipe fills with water.
Can I just do as in the second diagram and change the 2" 90 to a sanitary tee and connect the old 1-1/2" to that? Then I don't need to get rid of my roof penetration and the pipe won't fill with water and fall out or freeze. It seems logical to me, but venting is a lot more complicated than most people have any idea.
Some background. The primary bath was remodeled about 15 years ago -- before I owned the house. In the process, the old shower area now has the toilet room. To service the toilet, a new 2" vent was run as in the diagram. It runs up into the attic, turns 90 degrees, then lays flat on the trusses for about 4 feet, turns 90 degrees (still flat) and the another 4 feet until it turns up and exits the roof. My roof has concrete tiles. The 2" vent is sloped fine and the total horizontal run in the attic is probably 8 feet total.
In the process, they abandoned the old 1-1/2" shower vent. But, rather than fix the roof penetration, they just capped off the bottom of the vent pipe and left it hanging from the friction of the roof collar. Well, you know how well that worked. I found this pipe laying on its side in the attic with daylight coming in the roof penetration. Fortunately, I'm in a dry climate and no one ever noticed this in 15 years!
I'd rather not fix the roof penetration and I stuck the pipe back up through the flashing collar. This won't last once the capped off pipe fills with water.
Can I just do as in the second diagram and change the 2" 90 to a sanitary tee and connect the old 1-1/2" to that? Then I don't need to get rid of my roof penetration and the pipe won't fill with water and fall out or freeze. It seems logical to me, but venting is a lot more complicated than most people have any idea.