What step flashing means
Step flashing is a run of small bent metal pieces woven in with each course of shingles where a sloped roof meets a sidewall. Each piece laps the one below it, so water steps down and out onto the roof.
Where it matters on a roofing job
Step flashing should be replaced on a full reroof, not reused, because old pieces are bent and nailed through. If the wall has siding, the upper leg goes behind it, which can mean pulling a course of siding. Price that labor in the bid instead of finding it on the roof.
What the model code says
- Sidewall base flashing, continuous or step, must be at least 4 inches tall and 4 inches wide. (IRC 2021, Chapter 9)
Check which code edition your building department enforces for step flashing before you quote.
What it costs
The roof repair cost guide has the typical job at $1,100 and the usual range at $390 to $1,850. The guide shows its sources and what moves the price.
Work it out
- Cost guide: Roof repair cost
- Licensing: Roofing license rules by state
- Tools, templates and guides: Free roofing resources
Sources: 2021 International Residential Code, Chapter 9, Roof Assemblies (ICC). Checked October 9, 2026.