Direct Answer
A tear-off removes existing roofing so the underlying deck can be examined and the new roof assembly installed from that surface. An overlay leaves existing roofing in place and adds another covering. Tear-off offers more access to hidden conditions; overlay should be considered only after the existing assembly is shown to be suitable and the proposed installation is permitted.
For a Davenport homeowner, the first comparison is eligibility and scope, not the bottom-line price. An overlay proposal that leaves uncertain leaks, uneven material, or unexplained flashing details underneath is difficult to evaluate. A tear-off proposal also needs detail: removing shingles does not automatically include every deck repair or flashing replacement.
Define What Each Bid Actually Includes
Ask the estimator to state how many existing layers were identified and where that finding was verified. Roof sections can have different histories. A porch addition may not match the main house, and a previous repair can complicate assumptions based on one visible edge.
For tear-off, identify which materials will be removed, how the exposed deck will be assessed, and when photographs will be provided. Ask how the crew will protect openings if weather interrupts work. A proposal should distinguish the base scope from concealed conditions discovered after removal.
For overlay, ask what remains, what is removed locally, and how the new installation connects to eaves, valleys, penetrations, and wall transitions. A phrase such as new shingles over existing roofing is not a complete assembly description. Obtain the relevant product instructions and have the contractor explain how the proposed work complies.
Compare Access, Uncertainty, and Future Work
| Decision point | Tear-off proposal should explain | Overlay proposal should explain | Why it affects your choice |
|---|---|---|---|
| Roof deck condition | Inspection after removal and authorization for repairs | Evidence that the concealed deck is suitable and limits of that assessment | Covering uncertain deterioration can defer a necessary correction. |
| Existing leaks | How the entry path and affected materials will be addressed | How the cause will be corrected despite retaining material | A new visible surface does not identify an old leak source. |
| Flashing transitions | Which pieces are replaced, retained, or exposed for inspection | How added thickness works with walls, curbs, and existing details | The two bids may include very different water-management work. |
| Surface suitability | Preparation required before new underlayment | How the remaining surface meets the chosen product requirements | An uneven starting surface can complicate the proposed installation. |
| Approval and instructions | Responsibility for permits and inspections | Confirmation that this specific recovering approach is acceptable | Eligibility cannot be inferred from a neighbor’s project. |
| Hidden-condition charges | Decking units, documentation, and approval procedure | What discoveries could force conversion to tear-off | A contingency is more useful when its trigger is defined. |
| Next reroofing project | Materials that will eventually require removal | Additional retained material to remove later | Today’s avoided work can become part of a later scope. |
The table is a bid-review tool, not a declaration that either method is suitable for a particular house. Have both bidders describe the same property conditions before comparing their recommendations.
Resolve Eligibility Before Signing
Use the City of Davenport permit resources to confirm the applicable process with the city for the actual property and work. Ask who obtains any required permit, schedules inspections, and provides the final record. Do not rely on an unverified statement that overlays never require approval.
The existing roof’s condition and the selected manufacturer’s installation requirements also matter. Ask the contractor to identify the product and the instructions being used. A general assurance that another layer is common does not explain whether the roof in front of you meets the relevant conditions.
If information is missing, make the proposal conditional on resolving it before installation. For example, an unknown layer count should be verified, not silently treated as the favorable case. Have the contractor explain what changes the scope and how you would approve that change.
Give Hidden Damage a Written Process
Deck replacement is a frequent source of disagreement because it may be unclear until roofing is removed. Request a unit basis for additional work, the material specification, and photographs before authorization. Avoid assuming either that no repairs will be needed or that the whole deck must be replaced.
For an overlay, ask what evidence supports retaining the underlying assembly. If the answer depends only on the roof not leaking today, request a fuller explanation. A dry ceiling provides useful history, but it does not expose the deck or verify each concealed connection.
Recurring leakage deserves its own diagnosis. Ask where water enters, what materials have been affected, and what part of the proposed scope corrects that condition. If the explanation is merely that another layer will cover it, request more detail before proceeding.
Compare Financial Exposure Without Invented Savings
An overlay may avoid some immediate removal and disposal work, but a percentage savings cannot be assumed for every roof. Access, local removal, transition work, and the condition of the existing assembly influence the proposal. Compare actual written bids for the same roof and intended outcome.
For tear-off, separate the agreed price from allowances and unit-priced changes. For overlay, ask about conversion to tear-off if the retained surface proves unsuitable. Neither number is meaningful if one includes extensive flashing work and the other excludes it.
Consider your ownership plans without using them to excuse an unresolved problem. A short holding period does not make a concealed defect disappear. Keep documentation of what was retained, replaced, and inspected so a future buyer or contractor can understand the roof’s construction.
Hypothetical Example: A Dormer Changes the Comparison
Suppose two bids arrive for a Davenport house with an asphalt roof and a dormer that has leaked twice. One offers an overlay with a short description. The other includes removal and new flashing at the dormer. This is a hypothetical comparison, not a completed project or price claim.
The homeowner asks the overlay bidder how the dormer leak will be diagnosed and how its flashing will be integrated. The bidder adds local removal and investigation, then explains that concealed deterioration could expand the work. The revised scope is now more informative, even before the prices are compared.
The lesson is to identify the unresolved detail driving the decision. If the dormer assembly needs substantial exposure anyway, the practical advantage of retaining nearby roofing may change. That conclusion follows from the scope, not from a rule that one method always wins.
Ask for a Closeout Package
Before signing, agree on completion photographs, product identification, inspection records where applicable, and written warranty terms. Ask which company handles workmanship questions and what the manufacturer requires for the selected installation. Do not assume every warranty applies equally to every assembly.
The NRCA homeowner resources provide a starting point for broader contractor and roof-system questions. Use them alongside the actual contract rather than as evidence that a particular bidder’s design has been approved.
Discuss roof replacement options after the eligibility questions are answered. A useful recommendation should state what was observed, what remains uncertain, and why the selected approach addresses those conditions. Keep the scope and any approved changes with the property’s maintenance records.
Frequently Asked Questions
Is an overlay always allowed when there is only one shingle layer?
No. Layer count is only one consideration. The existing roof condition, roof assembly, product instructions, and applicable local requirements must also permit the proposed work.
Does tear-off include replacing all the roof decking?
No. Tear-off exposes the deck for assessment. The contract should explain what decking work is included and how additional replacement will be documented and authorized.
Will an overlay fix a recurring roof leak?
A new shingle layer does not establish or correct the cause of a recurring leak. The contractor should locate the entry path and explain how flashing, damaged materials, and other affected components will be addressed.