Guide 01 · Scope before product

Planning the Whole Roof Assembly

Use the deck, underlayment, flashings, panel and attachment method—not a material label—to compare installation proposals.

A metal-roof proposal should describe an assembly rather than a panel in isolation. The existing covering, deck condition, underlayment, ventilation, penetrations, edge metal, flashings and attachment method all affect the scope. Ask what can be inspected before tear-off, what is an allowance, how concealed damage will be documented and priced, and which party is responsible for permits and inspections.

Ask for the exact tested system

The proposal should name the manufacturer, panel profile, substrate, thickness, finish, seam or fastener method and applicable Florida Product Approval or other accepted evaluation. Those documents include limitations and installation details. Wind design is tied to the address, building dimensions, roof geometry, exposure and risk category, so a single countywide wind-speed promise is not a substitute for project criteria.

Treat tear-off as a site decision

Some assemblies may be installed over an existing roof covering, but the answer depends on the building and proposed system. Existing layers, deck condition, moisture, weight, fastening substrate, manufacturer instructions, code and permit requirements all matter. A proposal should state whether tear-off is included and how the contractor will handle any condition that changes the approved scope.

Before signing, verify the contractor’s active Florida license with the Department of Business and Professional Regulation and confirm that the proposal, permit application and product documents describe the same system. Product and workmanship warranties are separate promises; obtain both in writing and read exclusions before treating either as part of the value.

Qualified answers

Questions about planning the whole roof assembly

Can a metal roof be installed over shingles?

Sometimes, but only when the existing layers, deck, moisture conditions, manufacturer instructions, approved assembly and local requirements allow it. The property and proposed system must be evaluated before that scope is accepted.

What makes two installation proposals comparable?

They should identify the same panel, substrate, finish, underlayment, attachment, flashing scope, deck assumptions, permit responsibility and warranty terms. A total price without those details is not a complete comparison.

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Related proposal questions