I have a fireplace that I believe is called a 0 clearance. Purchased from Home depot,metal lined with firebrick. Am I right is that what this useless thing is called? I need to know can I put a woodburning fireplace insert in this? I would imagine the fire box is going to be too small for most inserts?? The exsisting pipe is 8" and I am under the impression that I will need to reline with 6" stainless. Please bring me up to speed so I can start heating with wood. thankyou dolores