Hi Guys. Anyone ever use an old chimney as a chase? I have a customer who wants receptacles above their fireplace which used to be a wood burning fireplace. It is no longer used as such but instead has an insert with a 4" exhaust up the existing chimney. I actually called the inspector and told him that the chimney is no longer used for exhausting a wood burning fireplace, therefore the temp will never get hot enough to do any damage. He was ok with it being used as a chase as long as I secured and maintained a distance between my BX and the 4" exhaust.
I've seen abandoned elevator and dumbwaiter hoistways used as chases...I don't see any real differences with your old chimney. Securing the raceway may be a bit tricky due to the small size of the chimney, but it certainly sounds like it would work.
I have other question to ask ya for the 4 inch insterst what class pipe you are seeing it ? if class A forget it it will get more than just warm engouh to get the cable get soft and can cause short circuit.
Class B is iffy question depending on how big the fireplace burner is.
Really I am not too crazy to leave it hanging loose in the chimeny area especally too close to the pipe.
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)
My first question would be, how old is the chimney? Reason I ask this is that boring holes in a brick chimney could weaken the structure of the chimney itself.
I have to agree with the comment of ghost about the cable being un-supported on a vertical run, you can't merely have a cable hanging in mid-air.
Regardless of age is there really a concern with structural integrity if there is a 1/2" hole drilled into it? To clarify other comments/suggestions the 4" duct going up the chimney is in a space that is about 8"wide. The BX is only loose in the chimney for about 24" and the rest is straped. If the home owner ever wanted a wood burning fireplace again I guess he would have to remove the BX and fix the holes and liners he drilled trough. Remember I did ask my local inspector if it was acceptable and he had no issues with it.
Personally I don't like it but thats what the customer wanted and it was accepted by inspection.