I'm getting ready to purchase my first wood insert this month, so I figured I'd go up and give the chimney a good sweep to clean it up for a new liner. When I started to sweep down the chimney I could see the a section of the clay liner wobbeling side to side as I swept. I'm guessing that this should not be happening, the section above it has no movement, nor the section below it from what I could see. The section is above the roof-line and incased in brick. Any Ideas what what to do??? thanks