There are several reasons that a Chimney can Leak. As a Basement Waterproofing Company, we address the issue at the Foundation. A chimney is basically another foundation that is attached to your basement and like the basement it can develop leaks over time.

If you have leaking or water stains coming from your chimney cleanout door, you will want the foundation of your chimney inspected. The chimney cleanout door is the back door to your chimney used for cleaning. As stated, leaking water or stains coming from this door usually indicates deterioration below grade (underground).

The cement and brick materials used to create the chimney are porous and over time will begin to degrade and erode mortar joints. This erosion and deterioration will allow more and more water into the chimney. Once this becomes severe enough the water will leak through the only real opening available which is the cleanout that leads into your basement.

Diagram of Chimney Waterproofing and Leak Repair