Stainless steel liner in furnace flu?

[Dan McCall]

Hi,
I recently purchased a house that was built in 1958. There are two flus, one for the fireplace and one for the hot water furnace in the basement. I have had four different estimates/opinions on the condition of the furnace flu and whether I need to shell out $3,000 for a stainless steel liner. Two chimney sweeps have said there is significant deterioration and I need to have this done or else I risk a fire or CO2 emissions in my house. Two others have said it is fine as is, and have confirmed there are no terra cotta pieces or debris at the bottom of the furnace, and also that the draft is adequate to expel all gases and emmissions. I have attached pictures I took yesterday after climbing on the roof and looking down the furnace. Note that the first joint in the picture is about three to five feet below the furnace top and is not adjacent or contacted to the house. I'd like opinions as to whether this work needs to be done and if so if there is anything I can do myself to save the money?

Thanks.

Dan

 

[webbie]

The flue itself looks fine. The joints between the flues look like they may be missing some mortar!

There is a simple process where a rubber stopper is lowered into the flue and some mortar poured down on top of it - and as the thing is dragged up, it pushed mortar into the joints! This may be an option.

A smoke test is the preferred method of finding out how much those joints may leak - most all joints will leak if exposed to such pressure, but at least you can see how bad it is.

You can see an example of flue joint services on this page (text):
http://www.chimneyprosmn.com/list-of-services/

 

[Eric Johnson]

I wouldn't worry about using that chimney for a fireplace or gas hot water heater, but if you're going to connect an air-controlled wood burning appliance to it, I'd get a liner. $3K seems excessive to me, but I understand that's an installed price. I'd probably lean more towards a DIY solution, depending on the size of the flue and the appliance outlet size.

Of course webbie's leak test is an excellent suggestion, but even without it, you're probably not in imminent danger. In my opinion.

 

[BrotherBart]

Eric is right. If nothing blocks the top then no pressure is going to develop to push anything through the joints. The gases will take the path of least resistance right to the sky.

 

[mikefrommaine]

Has anyone put a camera down the chimney? The joints may have plenty of mortar in them and what you are seeing from above is the extra mortar that squeezed out when the chimney was built is all that has fallen/detoriated.