I agree Dr Munger and that's the conversation or discussion I am trying to generate here. So many investigators now think we can't say this fire was caused by long-term heating with the additional caveat that the pipe runs very close to the wood above it and to one side. To clarify the furnace is again a gas fired Coleman installed new in 1994. It was installed in a closet type enclosure at one end of the bathtub. The flu is not surrounded by any ductwork it simply runs up from the unit about 2 to 3 feet and then elbows and runs laterally through the two floor studs and then elbows back up again. Again there is no separation the entire length of the pipe. Nor is there any separation as it comes out of the top of the unit. I simply find no other reason for this fire to occur and as stated in my first post the guy would have to have cut a hole in the ceiling to introduce something into the space to cause a fire which he has no real motive to set anyway.

Dave