Ovalizing rigid or flex pipe...

[Shari]

Okay, so here's my project:

We attempting to figure out what type of pipe to us to get through our damper. We would prefer rigid pipe but don't think that is going to work. Haven't (for sure) decided on which stove yet. Would love an Oakwood but $$ pretty much determines an Englander (13 or 30). Any way, here's pictures, suggestions welcome. Also suggestions on how to 'finish off' the vertical sides of the fireplace opening (veneer?). We had a dealer out here and they said they could not ovalize a freestanding stove through our flue. I believe I have read here on the list that others have ovalized pipe through their flues for free standing stoves. Flue measures roughly 8" x 15".

Shari

 

[Hogwildz]

You can ovalize a flex liner, but not chimney pipe. If the old flue is large enough, you could use a pc of flex from the stove outlet, through the old fireplace damper area, then up to first flue tile (a 5' pc should accomplish this length needed) then connect the flex to rigid the rest of the way up. Or run flex the entire way. As far as ovalizing, you can ovalize the flex, then re round the section after the damper to stove. Or cut a lil of the damper area out and it will give you a more straight shot to the stove with the liner.
I cut my damper out, ran double wall insulated rigid to the first flue tile, connected to round flex from the rigid, through the damper to the stove. Then make yourself a nice block off plate to enclose the damper area around the liner to keep the heat from going up and transferring through the masonry chimney walls.