DWV within shared wall townhouse

[Marc M]

Hey Jerry, I have a question regarding DWV within a common wall separating a townhouse / two adjoining units. If there are plastic dwv within this wall, how can it be effectively sealed when its plastic and two, per the exception below in bold; what is the "or what". Meaning, what is the fix if there is dwv within this wall? Hopefully I explained this well enough..

R302.2 Townhouses. Each townhouse shall be considered a
separate building and shall be separated by fire-resistancerated
wall assemblies meeting the requirements of Section
R302.1 for exterior walls.
Exception: A common 1-hour fire-resistance-rated wall
assembly tested in accordance with ASTM E 119 or UL
263 is permitted for townhouses if such walls do not contain
plumbing or mechanical equipment, ducts or vents in
the cavity of the common wall. The wall shall be rated for
fire exposure from both sides and shall extend to and be
tight against exterior walls and the underside of the roof
sheathing. etc...

[Jerry Peck - Codeman]

[Marc M]

I was hoping you weren't going to confirm what I suspected. It this image consistent with what you are describing?

[Jerry Peck - Codeman]

Basically, yes.

There could also be one common wall constructed as a 2 hr rated wall, with proper firestopping (versus fireblocking) for each item in that wall.

Of course, trying to construct a single common wall which will remain standing when the structure on one side falls is a bit difficult (unless the common wall is either CMU or poured concrete).

[Marc M]

All clear now, thanks much Jerry.