Price per square is useful only after scope is normalized. A lower proposal may omit tear-off, replacement flashing, ventilation corrections, accessories, permits, cleanup, or documented deck repair.
01 / Formula
How this is calculated
Replacement total = base roof system + removal + known repairs + allowances for unknown deck conditions + access/protection + permits/disposal + options02 / Assumptions
What the estimate assumes
- ✓Every proposal uses the same measured area or explains differences.
- ✓Products and installation details are named.
- ✓Unknown conditions use a written unit price or authorization process.
03 / Worked example
See the math in context
Put decking replacement at a stated price per sheet or square foot rather than hiding a speculative amount inside the roofing rate.
04 / Guidance
Review the complete water-shedding path
Confirm deck preparation, underlayment, ice barrier where required, eaves, rakes, valleys, walls, chimneys, penetrations, skylights, drip edge, starter, field covering, caps, and ventilation.
05 / Guidance
Read warranty boundaries
Separate manufacturer material coverage, enhanced-system coverage, installer workmanship warranty, transfer rules, ventilation conditions, exclusions, registration, and claim procedures.
Questions
Frequently asked
Can I measure or inspect a roof by walking on it?+
Do not access a roof without appropriate training, equipment, conditions, and fall protection. Use plans, ground measurements, aerial reports, or a qualified roofing professional when direct access is unsafe.
Does this calculator approve a roofing system?+
No. Verify deck condition, slope limits, underlayment, ice-barrier, flashing, ventilation, fasteners, wind requirements, fire classification, local code, and the exact manufacturer instructions.
What should be measured separately?+
Break out each roof plane plus valleys, hips, ridges, eaves, rakes, walls, penetrations, dormers, low-slope transitions, and special membranes. Geometry alone does not create a complete roofing order.
Sources