I throughly despise this type of fireplace gives me the thought of fire trap every time I see one and there are many many builders in this State that use this type of corner cutting to put more money in their pocket.
The interior is just wood frame with T1 siding on the exterior usually no cricket/saddle on the roof the siding is useally deteriorated from wicking water. The one in the pic is in better condition than most I see.
[size=2]The pic with the duct was taken actually from within the flue chamber looking up toward the roof pentration. Where you big guys are unable to fit.[/size]
[size=2]I use my weight as a marketing tool against the big guys 142 LBS soaking wet. I’ll bet Will Decker and RR don’t mention their size:) [/size]