A chimney fire is the most common cause of serious loss, damage and expense to a homeowner.
Suffering all of the weather changes that come with our lovely Irish climate causes stress to our chimneys. This stress from elements such as fire, wind, rain, storms can cause cracking. As can expansion of the flue liner in hot weather. And the oppisote effect of contraction and thermal shock in cold weather.
Example: Boiling water at 100 degrees will cause a glass to crack. Imagine what a fire burning at 900 degrees will do to your chimney liner. Eventually this has the potential to cause a chimney fire.