Inspected a townhouse today that had the required GB firewall separation, however, there is a PVC vent pipe coming through the GB, I presume, from the neighboring unit. I didn’t find anything regarding the fire rating of PVC or where it would be allowed through a firewall. However, I didn’t find where it was explicitly forbidden. Common knowledge would tell me it’s not allowed since it’ll melt in less than the 1-hour separation time and thus compromises the firewall. But, I’m not all that familiar with fire separation and I don’t know if there may be something that would allow this type of setup. Any knowledge would be appreciated.