Rust on metal chimney

[John Gromkoski]

I have seen this several times and am wondering what the exact cause of the rust on the metal chimney. Is it rust due to exposure to outdoor moisture - over time, or is it condensation caused corrosion? Or is there some other issue? How would you report this? Thanks.

[Charley L. Bottger]

Originally Posted by jgromkoski

I have seen this several times and am wondering what the exact cause of the rust on the metal chimney. Is it rust due to exposure to outdoor moisture - over time, or is it condensation caused corrosion? Or is there some other issue? How would you report this? Thanks.

John I get a little yancy when I see rust on the exterior of the double wall pipe which can be to any number of reasons. An old trick I use to determine if the rust is caused as a result of the inner lining being deteriorated which is my main concern. I just fire off the appliance and let if run for a while and if the duct located at the rusted spot burns my hand to where I can not hold on to it tells me the inner lining is gone its just a judgment call as its not visible. That is why the MFG of double wall pipe stamps the pipe 1 inch clearance to combustibles. Its strictly a safeguard for when the pipe starts to age.

[John Gromkoski]

How would you report it, assuming I did not perform the test you described?

[Joe Funderburk, CMI]

"The metal flue is badly corroded and should be replaced before it fully deteriorates."

[John Gromkoski]

Originally Posted by jfunderburk

"The metal flue is badly corroded and should be replaced before it fully deteriorates."

Thanks. Sometimes the answers are simple and right there. I just like to understand the reason for it, other than the obvious moisture and age, if there is one.

[Charley L. Bottger]

Originally Posted by jgromkoski

How would you report it, assuming I did not perform the test you described?

I don't fool around with CO pipe someone will go to sleep and not wake up.

If it's bad or even looks bad call for replacement better to error on the side of caution. I use the word (appears) a lot in my reports

[John Gromkoski]

Originally Posted by cbottger

I don't fool around with CO pipe someone will go to sleep and not wake up.

If it's bad or even looks bad call for replacement better to error on the side of caution. I use the word (appears) a lot in my reports

Charlie, that's usually the right way to approach such things.

As a side note, I also use the word appear(ed) a lot in my reports. I write my reports in the past tense because the reader will be reading it at a later time, and also because things that were defective may get corrected after my inspection. For instance, "appeared" instead of "appears", "was" instead of "is". I know there was some discussion about this method of report writing somewhere on this board in the past.

[Jeffrey R. Pope]

Originally Posted by cbottger

John I get a little yancy when I see rust on the exterior of the double wall pipe which can be to any number of reasons. An old trick I use to determine if the rust is caused as a result of the inner lining being deteriorated which is my main concern. I just fire off the appliance and let if run for a while and if the duct located at the rusted spot burns my hand to where I can not hold on to it tells me the inner lining is gone its just a judgment call as its not visible. That is why the MFG of double wall pipe stamps the pipe 1 inch clearance to combustibles. Its strictly a safeguard for when the pipe starts to age.

Good info Charley. Thanks.