Roof Flashing: Reuse, Replace, or Clarify Before Signing

Flashing manages water where the roof covering is interrupted or meets another surface. Those locations include sidewalls, headwalls, chimneys, plumbing vents, skylights, and changes in roof direction. A proposal that says only “flashing as needed” does not show which assemblies are included or how existing flashing will be treated.

This guide is a comparison tool, not an installation design. The local adopted code, existing wall construction, selected products, and manufacturer instructions determine the actual detail.

Inventory the flashing locations first

Walk around the house from the ground and list visible conditions without climbing onto the roof. Common proposal rows include:

• Eave-to-wall kick-out locations
• Roof-to-sidewall step flashing
• Headwall flashing
• Chimney base and counterflashing
• Plumbing vent boots
• Skylight kits or curbs
• Valleys
• Electrical mast or other penetrations
• Transitions between different roof slopes or materials

A line for each existing condition is easier to compare than one blanket flashing allowance.

What “reuse existing flashing” should answer

Reuse may be proposed for a particular component, but the document should identify the component and the inspection standard. Ask:

• Which flashing is intended for reuse?
• Can it be inspected before tear-off, or is the decision conditional?
• What condition triggers replacement?
• Is removal and reinstallation included?
• What happens if siding, masonry, or counterflashing must be disturbed?
• Is the reused assembly compatible with the selected roof system and its written warranty terms?

Do not assume “reuse” means the same thing for a pipe boot, step flashing behind siding, and chimney counterflashing. They are different assemblies with different access constraints.

What “new flashing included” should answer

New flashing language should identify the location, material or product, and related trade boundaries. At a roof-wall intersection, the water-management layers may involve the roof deck, underlayment, step flashing, kick-out diverter, wall drainage plane, and siding.

The U.S. Department of Energy’s Building America Solution Center describes step flashing overlapped in shingle fashion and integrated with the wall drainage plane. It also notes that coordination may be needed between roofing and siding work. That is why “new step flashing” should not silently imply that all wall-cladding removal and restoration is included.

Kick-out flashing deserves its own row

At the lower end of a roof-to-wall intersection, a kick-out diverter directs water away from the wall and toward the gutter. If the house has that condition, ask whether a new diverter is included, whether wall or gutter work is required, and who owns those related tasks.

The Building America guide recommends a corrosion-resistant, integrated detail and emphasizes inspection during installation. A proposal does not need to reproduce an installation manual, but it should identify the scope and responsible trade.

Chimneys and penetrations

For chimneys, distinguish base or step flashing from counterflashing cut into or attached to masonry. Ask whether masonry repair is excluded and whether a separate mason may be needed.

For pipe penetrations, identify the boot or flashing product and treatment of the existing pipe. Skylights should name the unit or flashing kit and state whether replacement, reuse, curb work, or interior finishing is included.

Sealant should not be used as a vague substitute for describing the assembly. Some systems use compatible sealants at defined locations, but the manufacturer’s detail controls.

Proposal comparison questions

1. List every flashing location included in the base total.
2. For each one, mark new, reused after inspection, separately priced, or excluded.
3. State the material or product where known.
4. Identify siding, masonry, gutter, and interior work boundaries.
5. Define the concealed-condition approval process and unit or quoted price method.
6. Confirm that installation follows the selected product instructions and locally adopted requirements.

Attach the exact proposal page and sentence to every comparison cell. “Not stated” means the document is silent; it does not establish what the contractor intends to do.

Continue with the water-protection scope guide, review the full proposal checklist, see the synthetic evidence example, or start a private comparison.

Sources

• Building America Solution Center: Step and Kick-Out Flashing at Roof-Wall Intersections
• International Code Council: 2024 IRC Section R903.2, Flashing
• GAF: Timberline LayerLock installation instructions

Local adopted code, permit requirements, product instructions, and the signed contract control the actual project.