large outdoor chimney?

[ilmbg]

A friend is building an outdoor fireplace on a large patio. There is a roof over the patio. She has looked for a large 'chimney' to hang over the firepit and go through the roof, but can't find one. The firepit is about 6-7 feet wide. Where can she look to find one- the contractor seems to think she doesn't need one, but there would be soot/smoke on the 'lower' side of the roof.... Thanks

 

[pen]

I think some pictures of this location and what is there now would be helpful.

pen

 

[madison]

Restaurant kitchen supply

 

[gmule]

Something like this?

 

[oldspark]

Have a welding shop make one something like this. http://copper-by-design.com/cc/cp/Takhar.htm

 

[begreen]

I would be concerned with the distance of the structure's ceiling to the firepit. For something like this I'd probably have a custom hood + vent pipe built. But what clearances to you use for the pipe to combustibles?