Furnace vent disconnected in attic

[kcflhrc]

So I have been chasing a roof leak for a few months. Was up in the attic yesterday and saw that the furnace vent pipe in the attic was not connected, like it had slipped apart. Wonder how long that has been like that? The pipe going out of the roof was offset from the one coming from the basement by about 2 inches or so. I temporarily was able to slide it over and wedge it in place and I put some of that adhesive foil duct tape around it. It doesn't look like there is enough slack in either direction to actually connect them, so I think it has been like that for some time. Any ideas on how to fix this without a great deal of trouble?

 

[TCJatko]

Depending on flue size and material, you may be able to purchase some kind of variable or 45 degree elbow to connect the pieces. You might have to trim. I'd use sheet metal screws after the installation to make sure it doesn't move again.

 

[kcflhrc]

Depending on flue size and material, you may be able to purchase some kind of variable or 45 degree elbow to connect the pieces. You might have to trim. I'd use sheet metal screws after the installation to make sure it doesn't move again.

Thanks for the info. I can actually line them up, there is just no vertical movement to put them together. My guess is it has been like this for a ling time. The house used to have a flat roof, Mansard style roof. However it was changed to a pitched roof at some point so I believe that is when the flue extension was probably added. Many, many years ago though, way before i owned it. The flat roof is actually still there, under the pitched roof. Do you think I could just wrap some tin around it and seal it somehow?

 

[Mendonsy]

It's probably not quite that simple. A furnace vent should be double wall pipe and the inner pipe gets hot. Just a band-aid approach probably won't last and could leak CO into your house.

 

[square1]

Adjustable 90 degree elbow then configure like this:

 

[kcflhrc]

At least in the attic this doesn't seem to be a double wall pipe. Keep in mind this house was built in 1970. In the basement where it goes between floors there is metal all away around the pipe where it goes through the floor. It looks to me like about an 8" round pipe, single wall, but a male/female type of groove connection. I will have to look at it again but it appears like I have 2 of the same end coming together, like a female/female with the groove. That adjustable elbow may be just the ticket. I just saw them at Home Depot, I need to measure the pipe though.

 

[KennyG]

It sounds a little cobbled. 8" would be huge for a furnace exhaust vent. Any way you can get it attached and sealed in the attic will probably be OK. I would worry about how the pipe is routed from the basement to the attic. For a gas furnace, codes typically require a 8" or 10" separation from any combustible surface if you use single wall pipe. That's pretty hard to get in most construction.

Just because it's been that way for years, don't get too comfortable. Leaks or close clearances will dry and sometimes char wood for years before conditions are finally right and it all goes up in smoke.

 

[kcflhrc]

My experience being here for about 2 years is there is a hole bunch of stuff cobbled together. I have chased electrical, plumbing and a host of other problems and corrected them. My nephew is an HVAC guy for Trane, I will have him look at it. I'm just glad I found it.

 

[kenmac]

the vent should be double wall vent..All the DW vent I've ever seen self lock together.. Screws are not required..By code,, DW vent only requires 1 '' clearance to combustible material.. SW vent is 6''

 

[oosik]

Your nephew will be able to get the situation corrected for you. If you have to have this kind of problem - this is definitely the time of year to find/fix it. Good luck.