I know this is a stupid question, but how hard is it to install double wall stove pipe in comparison to single wall? Is it a pain trying to get it connected or is it no harder than single wall? Please humor me, I have never seen double wall stove pipe other than pictures on the internet, which are not very good. No one has it in the stores here, so I have never been able to look at it up close. I know it's basically a stainless pipe inside a pipe, but I am having a hard time grasping specifically how it is installed. It just seems like it would be some trouble. Also, will there be noticeable gaps up at the stove pipe connector or at the flue of the stove, or will it fit flush with both?