Here are some pics from a new house that we had to bury some gasline at. One of our competitors is installing a fireplace there. It is a direct vent and the vent runs between the basement ceiling and the upstairs floor. The floor trusses have 24" from bottom to top. The pipe has approx. 3" of clearance all the way around it.
In South Dakota we do not have inspectors or any local codes. Will this be up to national code when the ceiling and walls are finished and the pipe will be completely concealed?
This picture is above the bottom of the truss
This is the pipe coming off the fireplace (can you put a 45 degree elbow right off the top of the fireplace?)
This is where the pipe terminates outside.