How to Compare Commercial Roofing Bids Fairly

Normalize scope before comparing price

Create a comparison for tear-off, insulation, taper, membrane or coating, flashings, penetrations, drains, edges, equipment, warranty, protection, permits, disposal, and closeout.

Expose assumptions and exclusions

A low bid may omit wet insulation, deck replacement, crane, permits, temporary protection, night work, warranty fees, or detail upgrades. List those items rather than burying them in narrative notes.

Separate base bid, alternates, and unit prices

Alternates should solve defined choices and unit prices should cover reasonably foreseeable variable work. That allows ownership to see true base cost and understand change exposure.

Practical owner checklist

• Build a line-by-line scope comparison.
• List exclusions and assumptions separately.
• Compare quantities, warranty terms, and alternates.
• Identify missing unit prices for likely concealed work.