Mississauga

You are looking at a gas fireplace vent that has been extended because the owner wanted to build a shed. He took off the original vent hood and put above the door. My question is the length ok? its about 10 feet? can you join 2 pieces together? Is the vent to the shed too close? what about for fresh air intake? for potential pre-list inspection. Thanks for your input. Click to Enlarge 31.89?KB Click to Enlarge 39.47?KB