Two roofing estimates can show very different totals even when both contractors are looking at the same house. The difference is often scope: one price may include full tear-off, flashing replacement, ventilation work, permits, and cleanup, while another leaves some of those items vague or treats them as added costs.
The best way to compare roofing estimates is line by line, not total by total. First make sure each contractor priced the same work. Then compare the material system, allowances, warranties, payment terms, and exclusions. A clear estimate makes it easier to spot where a lower number may create a change order later.
What should a roofing estimate include?
A useful roofing estimate should identify the contractor, describe the proposed work, name the major products, explain how uncertain conditions will be handled, and show when payments are due. The Federal Trade Commission recommends getting multiple written estimates and comparing the description of the work, materials, completion date, and price instead of automatically choosing the lowest bid.
Use the 12 line items below as a roofing estimate checklist. If a detail does not apply to your roof, the estimate can say so. What matters is that you can tell what is included, what is excluded, and what could change the final price.
1. Contractor identity, Illinois license, and insurance
The estimate should show the contractor’s legal business name, physical address, phone number, and Illinois roofing license number. Verify the license through the Illinois Department of Financial and Professional Regulation, and ask for current certificates of liability insurance and workers’ compensation coverage.
- Business name and street address
- Illinois roofing license name and number
- Current liability insurance
- Workers’ compensation coverage
2. Roof measurements and pricing assumptions
Look for the measured roof area, usually stated in roofing squares, plus assumptions about pitch, access, height, and complexity. Ask whether the price is based only on aerial measurements or includes an on-site inspection. Chimneys, skylights, dormers, steep slopes, and limited driveway access can change labor and equipment needs.
If you are still estimating the likely budget, review the Illinois roof replacement cost variables before comparing contractor totals. A calculator is a planning tool; the written scope for your actual roof is what makes two bids comparable.
3. Tear-off, number of layers, and disposal
The estimate should state whether the contractor will remove the existing roofing or install over it, how many layers are assumed, and whether hauling and disposal fees are included. A tear-off lets the crew inspect the roof deck and avoids covering defects that cannot be seen from the surface.
- Number of layers included in the price
- Dumpster or trailer placement
- Debris hauling and disposal fees
- Extra charge if another layer is discovered
Homeowners weighing those approaches can read more about tear-off versus roofing over existing shingles.
4. Roof decking inspection and replacement allowance
Damaged decking is often not fully visible until the old roof is removed. A strong estimate explains how the deck will be inspected and gives a unit price for replacement, such as a price per sheet or per square foot. Without that allowance, a low estimate can increase sharply after tear-off.
- Decking material and thickness
- Unit price for replacement
- Who authorizes added decking work
- How the change will be documented
5. Shingle manufacturer, product line, and color
“Architectural shingles” is not a complete product specification. The estimate should identify the manufacturer, exact product line, color selection process, and quantity. It should also say whether ridge-cap and starter shingles are purpose-made system components or shingles cut on site.
For a complete system comparison, ask whether the proposed products qualify for the manufacturer warranty described in the estimate. The Owens Corning estimate guide similarly recommends checking the shingle brand, product, color, underlayment, flashing, and ventilation details rather than accepting a generic material description.
6. Underlayment, ice protection, and drip edge
The estimate should name the underlayment and describe where ice-and-water protection will be installed. It should also address drip edge at eaves and rakes. These components manage water that gets beneath or moves around the shingle surface, so they should not be hidden inside a catch-all “roofing materials” line.
- Underlayment type and manufacturer
- Ice-and-water membrane locations
- Drip-edge material and color
- Compatibility with the selected roof system
7. Flashing, valleys, and roof penetrations
Ask what will happen at chimneys, sidewalls, valleys, plumbing vents, skylights, and other penetrations. The scope should distinguish between replacing flashing and reusing existing metal. Reuse may be appropriate in limited situations, but it should be an explicit decision rather than an assumption discovered during installation.
8. Attic and roof ventilation
A roof replacement is a good time to confirm that intake and exhaust ventilation work together. The estimate should show whether vents are being replaced, added, removed, or left unchanged. If a contractor recommends a different vent layout, ask for the reason and how the intake area will support it.
A professional inspection should connect visible roof conditions with the attic, flashing, drainage, and ventilation system. See what a roof inspection should include before deciding whether each estimate accounts for the full assembly.
9. Permits, inspections, and code-related work
The estimate should state who will determine permit requirements, obtain any required permit, schedule inspections, and pay the related fees. Rules can vary by municipality and project. Do not assume a permit is included just because one contractor’s total is higher.
10. Property protection, cleanup, and final inspection
Look for a description of how the crew will protect siding, windows, landscaping, driveways, and outdoor equipment. The scope should also cover daily cleanup, magnetic nail collection, debris removal, gutter cleaning where needed, and a final walk-through.
- Landscape and siding protection
- Driveway and material staging plan
- Daily and final cleanup
- Final inspection and punch-list process
11. Schedule, change orders, and payment terms
Compare estimated start and completion timing, deposit amount, progress payments, and the point when final payment is due. The proposal should also explain how unforeseen work is approved and priced. Avoid signing a document with blank spaces or relying on verbal promises that are not written into the agreement.
The National Roofing Contractors Association contractor checklist recommends a detailed written proposal covering specifications, approximate dates, payment procedures, supervision, quality control, and warranties. Those details reveal more about the job than the total alone.
12. Workmanship and manufacturer warranties
Separate the contractor’s workmanship warranty from the manufacturer’s material warranty. Ask how long each lasts, what it covers, what it excludes, whether registration is required, and who handles a future claim. A long warranty headline is less useful than clear written terms and a contractor who can be reached if a problem appears.
How do you compare roofing estimates side by side?
Build one comparison sheet with the same 12 rows for every contractor. Mark each item as included, excluded, an allowance, or unclear. Then request written clarification for every blank. This turns three different proposal formats into one shared scope.
- Normalize the scope. Confirm each bid uses the same tear-off assumptions, material type, flashing work, ventilation plan, and cleanup standard.
- Separate fixed prices from allowances. Record unit prices for decking or other concealed conditions that cannot be confirmed before tear-off.
- Compare product names, not categories. “Synthetic underlayment” and “architectural shingle” still leave meaningful choices unspecified.
- Read exclusions and change-order terms. These lines explain which risks remain with the homeowner.
- Compare accountability. Check license status, insurance, references, supervision, warranties, and who will be present during the work.
If one contractor is far lower, ask what that proposal excludes before treating the difference as savings. A useful answer is specific: fewer layers included, reused flashing, a different shingle system, no permit fee, or a narrower warranty. “We keep overhead low” does not explain a missing scope item.
What does Illinois require in roofing paperwork?
For covered home repair or remodeling work over $1,000, the Illinois Home Repair and Remodeling Act requires a written contract or work order before work begins. It must state the total cost, list parts and materials with reasonable particularity, disclose any estimate charge, and identify the business and its address. The Act also says roofing contracts, bids, and advertisements must include the contractor’s Illinois roofing license name and number. Review the current language in the Illinois General Assembly’s Home Repair and Remodeling Act.
That legal baseline does not make every roofing proposal equally useful. A homeowner still needs enough detail to compare products, installation choices, allowances, and warranties. This article provides general consumer information, not legal advice; ask a qualified Illinois attorney about a specific contract or dispute.
What are warning signs in a low roofing estimate?
- The Illinois roofing license number is missing or does not match the business.
- The materials are described only as “lifetime shingles” or “standard roofing materials.”
- There is no unit price for damaged decking or other concealed work.
- Flashing, ventilation, permits, disposal, or cleanup are not addressed.
- The contractor asks for full payment before the work is complete.
- Important promises are verbal, or the document contains blank spaces.
- The contractor pressures you to sign immediately or discourages comparison.
Price matters, but the safest comparison is price for the same scope. If the proposals are not describing the same roof system and responsibilities, their totals are not yet comparable.
Questions to ask a roofer before signing
- What exact shingle system and accessory products are included?
- How many existing layers does the price assume?
- What is the unit price for decking replacement?
- Which flashing will be replaced, and which may be reused?
- Does the ventilation plan include both intake and exhaust?
- Who obtains permits and pays the fees?
- Who supervises the crew and performs the final inspection?
- How are change orders documented and approved?
- What triggers each payment?
- What do the workmanship and manufacturer warranties exclude?
You can also review how to choose a roofing contractor in Illinois when license verification, references, and local accountability are part of the decision.
Get a written roof estimate from Trill Roofing
A clear estimate should help you understand the roof you are buying before work begins. Trill Roofing serves homeowners in Godfrey, Alton, Edwardsville, and surrounding Illinois communities with on-site inspections and written recommendations.
Request a free roof inspection to have Trill Roofing assess the roof and prepare a written estimate you can review line by line.
Frequently asked questions
How many roofing estimates should I get?
Get enough written estimates to compare scope, products, and contractor accountability; for many homeowners, that means two or three. More bids are not automatically better if the documents are vague or describe different work. Start with licensed, insured contractors and use the same questions for each.
Should I choose the lowest roofing estimate?
Not until you confirm it covers the same work as the other proposals. A lower estimate may be a good value, but it may also omit tear-off layers, decking allowances, flashing, ventilation, permits, or warranty coverage. Compare inclusions and exclusions before comparing totals.
Does a roofing estimate have to be itemized in Illinois?
Illinois law requires a written contract or work order before covered home repair work over $1,000 begins, including total cost and parts and materials listed with reasonable particularity. Roofing bids and contracts must also include the state roofing license name and number. A detailed line-item estimate is still useful because it makes products, allowances, and exclusions easier to compare.
What is a roof decking allowance?
A decking allowance is a stated unit price for replacing damaged roof sheathing discovered after tear-off. It may be expressed per sheet or per square foot. The allowance does not mean decking will definitely need replacement; it tells you how added work will be priced if hidden damage is found.
Should permit fees be included in a roofing estimate?
The proposal should say whether permits are required, who obtains them, and whether the fees are included. Requirements vary by municipality and project, so compare the written responsibility rather than assuming every contractor handled permits the same way.