Start where you are
Bids in hand. Now what?
You did the right thing and got more than one bid. Now they are on the table and none of them look alike. One is a page long, one is four pages, and the prices are thousands apart. This page is the order to read them in.
Jason Vogen · updated 2026-09-26
How to compare roofing bids
Do not start with the price. Start with the scope, which is the list of what each contractor is actually promising to do. Two bids for the same roof can be $3,000 apart and both be honest. One priced new flashing, ice and water shield up the eaves, and a ridge vent with the intake to feed it. The other priced shingles over what is there. The gap is not a discount. It is work that one of them left out.
Lay the bids side by side and read them into the same lines. Tear-off and how many layers. Decking, and what happens if a board is rotten. Underlayment and ice and water barrier, and how far up. Flashing, replaced or reused. Ventilation, with the numbers. Warranty, both the workmanship years and the manufacturer tier. Exclusions, in writing. When the same thing sits in the same row for every bid, the short scope shows itself without anyone saying a word.
What a siding estimate should include
Siding bids hide the same way. The price is for "siding replacement, all four elevations," and three weeks in the crew finds rotten sheathing behind the north wall. The contract never mentioned sheathing, so it is billed by the hour and the sheet. Nobody lied. A complete scope would have said what happens when rot is found and at what price.
A siding estimate should name the product and the profile, say what happens with sheathing and housewrap, cover the trim, the corners, the flashing at windows and doors, and the fasteners. It should say whether soffit and fascia are in or out. Window and gutter bids have their own short lists, and Guide 2 has a gap checklist for each trade.
Why the low bid is usually a short scope
A low number is not a red flag by itself. Sometimes a company is slow that month and wants the work. But more often the low bid is the one that assumed the most. "As needed." "To code." "If required." Those words move the cost to you later, when the wall is open and there is no time to get another bid.
The fix is not to throw out the low bid. The fix is to ask the bidder to make it complete. A good contractor will either add the line, and the price moves, or explain why it does not apply to your house. Both answers are useful. Silence is the one to worry about.
Questions to ask each bidder
- What happens if you find rotten decking or sheathing, and what is the price per sheet?
- Where exactly does the ice and water barrier go, and how many feet up?
- Is the flashing being replaced or reused? At the chimney? At the walls?
- What are the ventilation numbers for this roof, intake and exhaust, in writing?
- How many years is your workmanship warranty, and which manufacturer warranty tier is this?
- What is not included? Can you put that in writing?
- How is payment scheduled, and how do lien waivers work at the end?
Take the answers back to the bids and update them. Then, and only then, compare price.
Compare the bids you have, free
If you would rather have this done for you, send us the bids. We read each one into the same seventeen lines, mark what it states, what it leaves unclear, and what it does not mention, and print the questions to ask each bidder. We never rank the bids and we never judge the price. It is free for one project, and no contractor ever sees your files.