I had my roof completely redone last year. New asphalt shingles and several rotted boards of sheathing replaced. The roofers had to remove 3+ layers of old shingles so it was a substantial amount of work. In the process, they cut off the tops of several pipes venting from the roof. I am not sure what vents from these pipes and only noticed recently that they did not replace the caps/hoods to these pipes so they are completely exposed to elements. Would a roofer typically be responsible for replacing these caps if they cut them off? Is replacing the hoods/caps to them 100% necessary?