Ask what product is included
“Underlayment included” is not enough. Ask for the manufacturer and product type, where it will be installed and whether separate self-adhered leak-barrier materials are included where required or specified.
Coverage is not always equal to roof area
Overlaps, detail zones, valleys and waste can make ordered quantity differ from simple roof square footage.
| Quote detail | Verify |
|---|---|
| Main underlayment | Exact product and coverage |
| Leak barrier | Locations and width |
| Valleys | Underlayment and flashing approach |
| Penetrations | Integration with flashing |
| Deck | Surface condition and preparation |
Compatibility matters
Selection can differ by roof covering, slope, climate and manufacturer requirements. Do not select a product from price alone.
For a tile reroof, separate lifting and resetting the existing tile from renewing the hidden assembly. The tile roof quote calculator and scope guide helps combine that quoted work with excluded costs without counting underlayment twice.
Sources and verification
- NRCA, consumer roofing information
- OSHA, roofing safety
- FEMA, Building Science
- HomeCostEngine cost methodology
Planning limit: This page is for budgeting and scope comparison. A site inspection, local code review and written contractor proposal can materially change the final project cost.