Waterproofing is a preventative measure.  We Use a 
           chimney saver water repellent to waterproof your 
           chimney.  Water proofing protects the chimney from 
           water penetration and thaw damage, deterioration
           and staining.  Our chimney saver product is a water
           repellent that is breathable and allows water vapor 
           to escape.  When damage or deterioration (gaps, voids, 
           cracks, missing mortar, etc....already exist in a masonry
           structure), the chimney should be repaired before the 
           waterproofing agent is applied.
 *These pictures are all examples of water damage.*