Hello all,

A contractor installed an exhaust pipe for my oil furnace. It is a flexible (double-wall?) Z-Flex pipe. A few loops hanging from the ceiling of the crawlspace support the pipe. However, in two places he screwed the loop directly into the pipe. The screw penetrated right into the pipe. Is it how it should be done? My common sense says he just ruined the pipe... Plus this is an exhaust pipe so a leak can be poisonous... Should I demand they replace the pipe or is it ok???

Thanks a lot,
D.