I installed my direct vent LP fireplace insert over the weekend and installed the vent pipe through the existing chimney flue. After installing both pipes and getting the stove situated I noticed there was quite a cap in the flue around the liners. Anyone use insulation to seal this space? Will my vent pipe get too hot for fiberglas insulation? I am just worried about it maybe melting or causing a fire in the flue. I was going to stuff some fiberglass house insulation in there (with the paper removed) anyone think this is a good idea?