We moved into our house 13 years ago and replaced the woodstove. The chase is an external box attached to the house with pipe going up the middle of it. We have a chimney cleaner come two times a year and still have fires every year in that pipe that turns it an evil glowing red pipe in and out of the house. We have had it replaced. Our woodstove pipe has two 45 degree bends inside the house until the pipe leaves the wall of the house and runs approx 15-20 feet up. We can get a draw but we get horrid creosote buildup and the only other suggestion we have got is to insulate the existing chase around the pipe. Any suggestions on how to do that and what materials we would use???