The existing base
Deck condition, old roof layers, flatness and attachment support affect whether removal or a prepared recover is appropriate. Covering a wet or damaged base does not correct it.

Consider metal roof installation or replacement with the right panel system, flashing and movement details.
Standing seam hides its attachment beneath raised seams or clips. Exposed-fastener panels use visible fasteners through the sheet. Both are called metal roofing, but the joints, maintenance concerns and installation cost are different.
The panel system has to suit the roof pitch, shape and supporting deck. A long simple slope and a roof full of valleys, dormers and penetrations have very different amounts of metal detailing.

Compare the actual specified system rather than the broad label “metal roof.”
Metal expands and contracts with temperature. A penetration should not lock a moving panel into a detail that cannot move with it. A pipe flashing or curb needs the correct support and connection for the selected system.
This also matters when solar, antennas or new mechanical equipment are added later. Coordinate the attachment and water protection with the roofing system rather than treating a hole in the panel as a small unrelated task.

The covering is only part of the proposal. These items can change the installed cost and the suitability of an overlay.
Deck condition, old roof layers, flatness and attachment support affect whether removal or a prepared recover is appropriate. Covering a wet or damaged base does not correct it.
Underlayment and ventilation details should suit the assembly. Condensation control depends on the building and roof construction, not the metal color alone.
Valleys, dormers, chimneys, wall transitions and custom trim add fabrication and labor. Their connections should be part of the scope from the start.
Sound depends on the whole roof and ceiling assembly, including decking and insulation. An open metal shelter and a metal roof over a finished house are different situations. Discuss the actual assembly when noise is a concern.
Hail can dent panels, damage finishes or affect connections, depending on the event and system. Cosmetic change and a leak-producing defect are different questions, and policy language may treat them differently.
Sometimes a recover is a suitable design, but the roof’s condition, layers, local requirements and manufacturer details must support it. An overlay should not conceal damaged decking or active moisture.
Metal often has a higher initial installed cost, particularly for standing seam and complex roof shapes. Compare complete assemblies rather than panel and shingle prices alone. See the roof budget guide for the scope differences.

Request a free inspection to discuss whether metal fits your roof, how the details would be handled and what belongs in the project scope.