5x8 chimney adapter possible?

[murray1113]

Looking at a non traditional installation. Customer has a wood stove, venting goes up a few feet then 90 into masonry chimney thimble.

Customer wants to remove wood stove, install new thimble in chimney lower down and install a zero clearance gas fireplace, build around it, and have a shelf above set back for a TV.

The problem is the zero clearance he wants has a 5x8 rear vent, I can't find a 5x8 masonry chimney adapter anywhere. I can get 5" gas flex venting for the chimney. Manufacturer does not allow reducing to 4x6 unless using the top vent (Can't use the top vent because of the set back shelf he wants to have).

Anyone have a 5x8 masonry chimney adaptor?

Thanks

 

[Heatsource]

looks like simpson only makes those parts for the 4x6 5/8 pipe

 

[DAKSY]

Looking at the DV pipe available in the 5x8 size, you might be better
off removing the ENTIRE masonry structure, but that will probably entail
additional siding repairs...
Another option would be blasting a hole right thru the masonry chimney & mounting a
horizontal DV cap to the outside,with the wall pass thru on the inner wall.
Then you could rigid DV from the back of the fireplace to the cap. Masonry adapter not required.

 

[double-d]

Why not just use a 5" x 8" oval to 6" round cu$tom adapter, then just run 6" pipe to the thimble? I did something like that last year and it worked for my situation.

 

[DAKSY]

Why not just use a 5" x 8" oval to 6" round cu$tom adapter, then just run 6" pipe to the thimble? I did something like that last year and it worked for my situation.

I absolutely do NOT recommend modifying ANY gas vent components. Use the recommended venting or don't install it.