New roof coverings shall not be installed without first removing existing roof coverings where any of the following occur:
1. Where the existing roof covering is wood shake, slate, clay or asbestos tile.
2. Where the existing roof has two or more applications of any type of roof covering.
3. Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.
These are both State & City Laws
Please call 410-548-3170 or 410-548-3130 if you have any questions.