I have an older home & I'm guessing whomever installed the wood stove, pipe was not thinking.. IDK.. I have a Franklin wood stove & the pipe goes from a 6" single wall to an 8" triple wall stove pipe at the ceiling. Which is correct, it is braced correctly and the pipe from the ceiling threw the attic out to the roof tp is correct. What is NOT correct is it goes from single to triple wall with NO reducer/increaser. I've just recently noticed there was something wrong because my ceiling around the stove pipe has started to droop. Upon further investigation, the reason it's sagging is because water has leaked on the drywall and slowly weighted it down to where I'm going to have to replace the drywall.. here's the dilemma.... The water is NOT leaking from a hole or spot in roof, its coming from INSIDE the stove pipe. IDK if it's condensation or what, but when it happens it's from a slight drip to a flow of water. (almost like someone is on the roof with a glass of water.) It's done it when there hasn't been any snow/rain in days. I would like to know if anyone has ever had this issue, if anyone has an explanation as to why it would drip from INSIDE the triple walled pipe & if I put an increaser/reducer on will the water evaporate instead of running down the remaining pipe?