Compare the full reroof plan, not one total at the bottom
Normalize Roof Replacement Bids
Compare removal, assembly, details, allowances, and closeout on equal terms.
Document the actual condition
Replacement totals are not comparable until they describe the same roof areas, removal limits, assembly layers, transitions, and finish details. Give each bidder one roof plan, leak history, prior reroof record, access list, and owner priorities, whether the likely covering is composition shingle, tile, or a low-slope membrane.
Set the inspection questions
Require bidders to identify inspection limits and assumptions, then normalize covering, underlayment, ventilation when applicable, flashing, penetrations, edges, drainage interfaces, substrate allowance, cleanup, and closeout. Product names alone do not explain how the full assembly connects at valleys, walls, curbs, or adjoining roofs.
Write a comparable scope
Separate base scope, alternates, exclusions, unit prices, permit responsibility, and payment milestones. Preserve every proposal revision and record why a system or alternate was selected. Where the roof condition, occupancy, or multiple trades make scoping uncertain, use a paid evaluation before treating a preliminary total as a construction price.
Preserve the decision record
Build a one-page comparison table with roof areas as rows and assembly components as columns. Enter “excluded” or “not stated” instead of leaving blanks. That format quickly reveals when one bidder omitted a transition, substrate allowance, drainage interface, or closeout item and makes follow-up questions more useful than negotiating from totals alone.
- Mark omitted components as excluded or not stated
- Compare transitions and substrate allowances before total price