The white stains, or powder-like material, are often the result of water penetration into the chimney. During a rain, snow, or ice storm, water is absorbed by the brick and mortar crown. In the case of snow or ice storms, freeze-thaw cycles can enlarge the cracks on the top of the chimney mortar crown, allowing water to enter the structure this way. The chimney will soon saturate with water. As the chimney dries, lime and salts from brick and mortar are pushed out of the pores of the chimney. Wood in contact with a chimney can also absorb water and, in most cases, start to rot. This is a common problem that we can help prevent. The cost of this service depends on many factors. Call us for more information or to schedule a visit.