Vent size two toilets

[DavidTu]

Each of two toilets is vented with 2" pipe. When I bring the two vertical vent sections together can the combined vent stay at 2" or does it then upsize to 3"? In looking at my plans it seems at the time I thought it had too go to 3" but now I don't see a reason to do so.

[Terry]

You can vent three bathroom sets with 2" in Seattle as long as you have the required combined area total using other vents too.
If the home has a 3" line, then using two 2" vents and one 1-1/2" vent flies.

[hj]

As Terry said, HOW you can combine vents depends on the total AREA, not diameters, of ALL the pipes exiting through the roof. IF you have the proper area, you can combine vents inside the building pretty much as necessary, because it would be an unusual residence where merging the vents would result in an undersized vent.

[DavidTu]

Just to be clear I am asking about combining the vents inside the building. Sounds like 2" is fine for both. They will eventually join other vents and go vtr at 3".

[hj]

WE knew WHAT you wanted to do, but HOW you did it was the thing which determined IF you could do it.