Outdoor fireplace help

[Shifty]

Hey guys little help from the hive mind please. Helped a friend work on this out door fireplace on the porch of his hunting club this weekend. Got the shell finished now just needs firebrick veneer and chimney finished. He needs to go from a 16x16 opening on top of the masonry to a 12 inch chimney pipe. Ideas? Links appreciated. Thanks in advance

 

[FPX Dude]

Hmmmm, go at least another 6-8ft.+ on the chimney though. Friend of mine has an outdoor setup like that and all it takes is a little down-draft breeze and everyone is smoke'd out. Is that what you're asking?

 

[Shifty]

Hmmmm, go at least another 6-8ft.+ on the chimney though. Friend of mine has an outdoor setup like that and all it takes is a little down-draft breeze and everyone is smoke'd out. Is that what you're asking?

Thanks for reply. Yes will extend another 6-8 feet but will be transitioning from masonry to chimney pipe. I’ve about decided to mortar in a flat chimney cap and tie in 12 inch pipe up and through or around porch roof.