I have an new insert with ss ribbed pipe running through terra-cotta lined chimney with pipe exiting through plate sealed to top...there is a slight offset above the firebox so the pipe is touching at some point....Had it cleaned before install but I didn't inspect the work afterward, pretty sure it needed it badly...my question is: Do I have to worry about a fire in the chimney if they guy didn't do a good job sweeping? Also, do I have to consider cleaning this space after some time even if it were cleaned well? I heard someone reference cleaning the pipe and the chimney...thanks...