Should old flashing be reused during a roof replacement?
Short Answer
Sometimes it can be, but it should not be assumed that reuse is appropriate. The condition, design, compatibility and accessibility of the existing flashing should be evaluated. Certain flashing details are difficult or impossible to properly replace after the new roof covering has been installed.
Detailed Explanation
Reusing old flashing can save money, but it's a calculated risk. If the existing flashing is in good condition, properly designed, and compatible with the new roofing system, reuse may be appropriate. But if the flashing is corroded, dented, improperly installed, or incompatible with the new shingles, reusing it means installing a new roof over a known weakness. Some flashing — like step flashing at roof-to-wall transitions — is very difficult to replace after the new shingles and siding are in place, so it's best to replace it during the roof replacement when access is available. A responsible contractor evaluates each flashing condition and recommends replacement where warranted rather than defaulting to reuse to lower the price.
Why It Matters
Reusing deteriorated flashing to save money on a roof replacement is a false economy — it creates a known weak point in an otherwise new system.
Common Mistakes
- ✕Defaulting to reuse to lower the proposal price
- ✕Not evaluating flashing condition before deciding
- ✕Not replacing step flashing that won't be accessible later
When Repair Makes Sense
Existing flashing is in excellent condition, properly designed, and compatible with the new system.
When Replacement Makes Sense
Flashing shows any sign of deterioration, was improperly installed, or won't be accessible after the new roof is installed.
Questions to Ask Your Contractor
- ?Will existing flashing be reused or replaced?
- ?What condition is the existing flashing in?
- ?Which flashing details won't be accessible after the new roof is installed?
- ?What's the cost difference between reuse and replacement?