Unexpected Problems

[W.B.]

Well, I had planned on installing a 6" ss flex liner into my chimney for the new nc-13 insert. This planning was based on an estimate I received by a local sweep. He told me that I had an 8"x13" inner diameter flue tile.

I finally got a chance to get up on the roof today and he was WAY off. The actual inner diameter of my flue tiles are roughly 6"x16". I've also got some pretty big gaps between some of the flue tiles, so insulation is going to me a must.

Is it even possible to ovalize a 6" liner to get it small enough that it will fit inside this flue with insulation? I'm not sure what I'm going to do at this point.

 

[Jags]

Yes, you can ovalize a 6" liner. Be aware that a 5.5" liner does exist (but I don't know any specs) if that would help.

 

[jtp10181]

We install insulated 6" SS liners down 8x12 OD flues, which are around 6x10 ID I think.

We ovalize the liner down to 4" on the small side. Fits down just fine at that point.

 

[weatherguy]

I think you could drop some vermiculite down after you put the liner in for insulation, it would be hard to wrap it and slide it down.

 

[jtp10181]

I think you could drop some vermiculite down after you put the liner in for insulation, it would be hard to wrap it and slide it down.

Not hard if you get it the right size. You cannot use random insulation products in random amounts, you need to follow mfg specs. For example, Ventinox specs out Thermix, but you must be able to get at least 1" all the way around the liner. In a tight flue it is easier to do the 1/2" of insulation.