There are several contributing factors as to why a chimney may leak. You could have a deteriorated crown, the exterior chimney could have missing mortar joints, the flashing could be bad, or you could simply need a new rain cap. In some cases, it may not even be a leak at all. It could be condensation from a high efficiency gas or oil furnace or boiler with an oversized flue. Finding the origin of a leak can be difficult, so don’t allow other companies to play process of elimination with your hard-earned money. Advance Chimney Sweeps will meticulously look over your chimney as to help ascertain the problem.