I was just wondering if anyone has experience with these liners.I know rigid liner is always preferred, but with a price up to $60/ft or more not including installation ,the flexible liner looks a lot better. My existing chimney is brick with 7x11 terra cotta (sp) liner in decent condition. I mostly want a bit of peace of mind with a steel liner.If there is a certain brand or minimum thickness anyone recommends I would like to hear your thoughts. I also do plan to get some advice from a professional chimney sweep before I do anything, but real world experience to me is priceless.