Asphalt Shingle Roof Replacement: What to Understand Before Work Starts

Asphalt shingle replacement involves more than swapping old shingles for new ones. Understanding the components involved helps you ask better questions and know what to expect during the project.

Tear-off vs. overlay considerations

A full tear-off removes existing layers down to the decking, while an overlay adds new shingles over an existing layer. Whether an overlay is appropriate depends on the existing roof's condition, layer count, and local code — it isn't a universal shortcut.

What a full replacement typically involves

• Decking checks: the wood decking underneath is inspected for damage once old material is removed, and any damaged sections are addressed before new roofing goes down.
• Underlayment: a protective layer installed directly on the decking before shingles go down.
• Flashing: metal detailing around chimneys, vents, skylights, and roof edges that directs water away from vulnerable areas.
• Ventilation: existing ventilation is often reviewed and may be adjusted as part of the project.
• Drip edge: metal edging along the roof's perimeter that directs water into gutters and protects the edge of the decking.
• Ridge caps: the shingles that finish the roof's peak, installed last.

Cleanup expectations

A roof replacement generates debris — old shingles, nails, and packaging. A clear understanding of the cleanup and debris-removal process, including yard and landscaping protection, is worth discussing before work starts.

Questions worth asking before work starts

• What happens if decking damage is found once tear-off begins?
• What underlayment and flashing approach is planned for this roof?
• Will ventilation be reviewed or adjusted?
• What does the cleanup and debris-removal process include?
• What documentation will be provided once the project is complete?