I would like to use my fireplace as wood burning. It currently has gas piped up through the floor. I have read that I need to cap it. I also read that if the fireplace was orignally gas that it cannot withstand a wood fire. How do I know if it was originally gas or wood? The fireplace looks and feels like brick, also the gas line comes up through a hole that is much larger than the pipe, making me think that it was added on later.