Help! We have a wood fireplace that has an excessive smoke problem. Smoke will pour out of the fireplace into the house unless a window or door is open until a roaring fire is underway. Then, the fireplace will start to smoke again once the fire is dying down for the evening. I'm not sure if this has anything to do with it, but the house is a SIP home (structurally insulated panel). The house & fireplace is 3 1/2 years old. Does anyone have any ideas why this is happening and how to fix it? Any help is appreciated.