kscowboy's add-on furnace and chimney repair thread

Doesn't sound unreasonable, given the materials alone could run $1000. Could be done by homeowner for sure, but if you are not certain of your skills, leave it to a pro and get it inspected.

Depends somewhat on the size / shape / condition of the existing chimney... Unless it is really falling apart, I don't see a lot of advantage to using a "Class A" prefab chimney - you already have fire protection from the chimney structure, so you don't need those extra layers of metal... If by "double wall pipe" you meant a double wall connector pipe, that is a definite no-no, as code does not permit that type of pipe to be installed where it can't be seen.

Assuming the chimney is structurally sound, my first choice would be rigid stainless liner if the flue is straight, or flex if it isn't... Sometimes if you just have a bend at the bottom (say to go around a smoke shelf) you can use rigid for most of the distance, and just stick a length of flex on the bottom to go around the bendy bit...

A top and bottom block-off plate is also strongly recommended, if at all possible.

In either case, if there is enough room in the flue to allow it, I would STRONGLY recommend insulating the liner, as doing so greatly improves chimney performance, and can reduce creosote buildup. If the chimney is not NFPA 211 compliant (i.e. clay tile lined, w/ tiles in good repair) the insulation is required.

If you don't have room for a full insulation jacket, and have installed a bottom block-off, then you can get at least some benefit by pouring the space between the liner and chimney flue full of vermiculite, or one of the insulating concrete mixes sold for this.

Gooserider

kscowboy said:

I do all my other work on the house would feel comfortable doing work my self with and inspection at finish does any one know if where the chimney ends in the attic can liner be connected to triple wall to finish it out of the roof or can the liner be used

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I'm not quite following - are you saying that you have chimneys that end in the attic someplace? What were they used for? Are they old chimneys that got "chopped off" during some previous "home improvement" project?

If they are old chimneys that got chopped, I'd want to have some really serious inspection done on them before trying to reuse them, as you want to make sure that they are still in decent shape, without any problematic damage from the previous demo work...

Depending on what you find, and possibly some pricing, the three choices I would see are

1. Demo the existing chimney the rest of the way to the ground, and then go up through the space with Class A prefab chimney (What I think you were calling triple-wall, but there is some Class A that is only double wall with solid packed insulation between the layers)

2. Build the existing chimney back up to code required height, and probably install an insulated liner

3. Come up with some hardware to make the transition at the end of the existing chimney, and go up with Class A, and down with an insulated liner - I'm not sure what hardware exists to do this, but far as I know it would be a legitimate option as long as you did all the proper clearances to combustibles and so forth. You CAN'T use the chimney liner to go up, as it is only approved for use inside a chimney, or possibly in a short length to connect to an appliance in a fireplace or similar environment.

Also, I have noticed you've gotten several threads going on similar subjects - I'm going to start merging them together so as to keep the discussion in one place and reduce confusion... IMHO it's a good idea to keep at least major phases of a single project inside a single thread, it avoids duplicate replies, etc...

Gooserider