01
Using cement instead of repairable details
Broad roof-cement patches can trap water, cover evidence and make later slate removal more destructive. Durable repairs replace failed pieces or metal and preserve the overlapping drainage system.
02
Ignoring layout and fastening fundamentals
Insufficient headlap, misaligned joints, tight nails, poorly placed holes and unsupported slate can create recurring failures. These problems are not corrected by a better underlayment hidden below them.
03
Replacing a roof without diagnosing it
Old flashings or isolated broken pieces can be mistaken for complete slate failure. Conversely, cosmetic spot repairs should not hide widespread deterioration. A documented condition survey should come before a major recommendation.