The whole-house project
Metal roof replacement and inspection in New Hampshire
A metal roof replacement in New Hampshire starts with an inspection and a written estimate, not a price over the phone. An independent local professional measures the roof, looks at the deck, seams, fasteners and flashing, then puts the panel system, gauge, finish and a per-sheet decking price in writing. That inspection and estimate are free, statewide.
The first real decision inside that estimate is tear-off or roofing over. New Hampshire's state building code adopts eight model codes by reference, seven from the International Code Council plus the National Electrical Code (RSA 155-A:1, IV, read at the statute on 2026-08-25), and the reroofing sections of the three that cover a roof set no percentage limit on how much of a roof may be replaced or covered over. They decide it by condition, and all three name standing seam metal roof systems as a system that may go over an existing roof covering.
Most standing seam projects here start as an asphalt roof on its second or third round of trouble. Replacing it with metal is a different project than another shingle job, with its own sequence, decisions, and honest tradeoffs. Here is what the code allows, what the inspection finds, what the estimate has to say, and what the project actually looks like.
What does a metal roof replacement cost in New Hampshire?
Roughly $8 to $39 per square foot installed, which works out to about $7,540 to $39,430 on a 1,000 square foot roof and $15,080 to $78,860 at 2,000 square feet. Those are This Old House figures, priced from RSMeans data and updated March 2026, re-read at the source on 2026-08-25. Two other national guides put the same job far lower, so the honest version is a spread rather than a band: Today's Homeowner at $10 to $20 per square foot and Bob Vila at $2 to $10.
None of those are New Hampshire quotes and none of them are ours. Tear-off, deck repair, pitch, and trim complexity move the number, and so does the panel system itself. The line-by-line version with a worked example is the NH metal roof cost guide, and the system choices behind the quote are explained under standing seam metal roofing.
One flag worth repeating: no tax credit or rebate applies to a New Hampshire metal roof. The federal 25C credit expired at the end of 2025, and NHSaves has no roofing rebate. A pitch that leans on either is out of date at best.
What do they do for a metal roof inspection?
They walk the roof against a checklist, and the training material is public. InterNACHI's inspector course Mastering Roof Inspections: Metal Roofs, by Kenton Shepard and Nick Gromicko, sends an inspector through the slope, the sheathing, the underlayment, the seams, the panel edges, the fastening system, and the flashing and sealant at every penetration. That is national inspector training rather than a New Hampshire rule, and it is the closest thing to a published standard for what a metal roof inspection covers.
- Slope. "Metal roofing should never be installed at a slope lower than the minimum recommended by the manufacturer."
- Seams. "Seams are a weak point in the system. A variety of profiles is used on different roofs to prevent moisture penetration."
- Edges and fastening. "The areas of metal panel roofs most vulnerable to wind are panel edges at the peak and eaves, and along the rakes."
- Sealant. "Any installation that relies on a sealant to prevent moisture intrusion will need to have new sealant applied on a regular basis."
- The deck under it. Sheathing condition and underlayment, which decide whether the next roof starts on clean wood.
That last one is why an inspection matters before a replacement quote is worth anything. A number produced from a satellite measurement has not seen the deck, and deck repair is priced per sheet on top of the ranges above.
What will fail a metal roof inspection?
The four conditions above, found and left. A panel run laid below the manufacturer's minimum slope, open or deformed seams, lifted panel edges at the eaves and rakes after a wind event, and a penetration held together by sealant nobody has renewed. Exposed-fastener roofs add their own version of the fastening check, the screw and gasket condition covered under metal roof repair, and the replace-or-repair split is further down this page.
Do you have to tear off shingles before a metal roof in New Hampshire?
Not always. The reroofing section of New Hampshire's adopted residential code starts from removal: at Section R908.3, read at the state-adopted code text on 2026-08-25, "roof replacement shall include the removal of existing layers of roof coverings down to the roof deck." The very next subsection then lists the cases where a new covering may go over the old one, and the second of them is written for the product this site is about: "Complete and separate roofing systems, such as standing-seam metal roof systems, that are designed to transmit the roof loads directly to the building's structural system and do not rely on existing roofs and roof coverings for support, shall not require the removal of existing roof coverings." The building code carries the same rule at Section 1512.2.1, and the existing building code carries it at Section 705.2.1.
Three conditions stop a roof recover outright. Section R908.3.1.1 does not allow one:
- "Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing."
- "Where the existing roof covering is slate, clay, cement or asbestos-cement tile."
- "Where the existing roof has two or more applications of any type of roof covering." A roof already carrying two layers cannot take a third.
Tear-off is still the default recommendation on most of these projects, and the reason is what the code cannot see. Stripping the old shingles exposes the deck, so rot, delaminated sheathing, and past leak damage get fixed instead of buried, and the new ice and water barrier plus synthetic underlayment start on clean wood. Going over shingles saves tear-off and disposal money and buries whatever the old roof was hiding. Panel manufacturers also set their own installation instructions, and the code's first listed case for a recover is a covering "installed in accordance with the roof covering manufacturer's approved instructions", so the panel maker's instructions are part of the test rather than a separate opinion. A bidder who recommends going over shingles without probing the deck is answering the price question, not the roof question.
What is the 25 percent rule for roofing?
There is no 25 percent rule for a New Hampshire house re-roof. All three reroofing sections above were read end to end on 2026-08-25 and none of them limits how much of a roof may be replaced or covered over by area or by percentage. Exactly one 25 percent figure attaches to a reroofing permit anywhere in them, at Section 706.3.1 of the existing building code, in the part headed additional requirements for reroof permits, and it is not about roof coverings at all: "Where a permit is issued for reroofing for more than 25 percent of the roof area of a building assigned to Seismic Design Category D, E or F that has parapets constructed of unreinforced masonry, the work shall include installation of parapet bracing unless an evaluation demonstrates compliance of such items."
Two things have to be true together before that applies: the building is assigned to Seismic Design Category D, E or F, and it has parapets built of unreinforced masonry. If your roof has no unreinforced masonry parapet, that provision is not describing your job, and if you are unsure which seismic design category your building falls in, your building official is the person to ask. One caution before you treat this as settled statewide: RSA 155-A:2, VIII, in the version in force since July 1, 2026, says nothing in the building code chapter supersedes local law except "local code requirements that are less stringent than the state building code", so a town is free to be stricter than the state. Ask your local building office what applies on your street before you plan the job around any rule you read online, this page included.
Which code governs a metal roof replacement, and who issues the permit?
The state building code governs the work, and your town or city issues the permit. RSA 155-A:2, I, read in full on 2026-08-25, puts a re-roof squarely inside it: "the construction, design, structure, maintenance, and use of all buildings or structures to be erected and the alteration, renovation, rehabilitation, repair, removal, or demolition of all buildings and structures previously erected shall be governed by the provisions of the state building code." Paragraph IV then reserves the paperwork to local government: "the issuance of permits and certificates of occupancy pursuant to the state building code is expressly reserved for counties, towns, cities, and village districts", excepting state-owned buildings. That is why no page here tells you whether your particular re-roof needs a permit. Your building office answers that, and the metal roofing contractors in New Hampshire page carries the rest of what RSA 155-A:2 puts on the contractor, including why no page here names a code edition.
Does roofing over shingles add too much weight for New Hampshire snow load?
The code sets the trigger at 5 percent, and its first exception is written for houses. Section 706.2 of the existing building code says any existing gravity load-carrying structural element "for which an alteration causes an increase in design dead, live or snow load, including snow drift effects, of more than 5 percent shall be replaced or altered as needed to carry the gravity loads required by the International Building Code for new structures." Two exceptions follow. The first covers buildings of Group R occupancy with not more than five dwelling or sleeping units used solely for residential purposes, where the altered building complies with conventional light-frame construction methods or the residential code, which covers a typical one- or two-family house. The second covers a building whose added dead load is entirely "the addition of a second layer of roof covering weighing 3 pounds per square foot or less over an existing single layer of roof covering."
Two practical readings come out of that. Ask the bidder for the panel system's installed weight per square foot in writing rather than taking a general claim about metal being light. And read the load the roof is designed for alongside it: the ground snow loads this state uses run from the Seacoast to the high townships, and they are laid out on high snow load roofing.
What a metal roof replacement estimate has to include
Panel system, gauge and finish by name, the underlayment, a per-sheet decking price, who pulls the permit, the payment schedule, and the start and completion window. New Hampshire issues no roofing license, so the written estimate is the document doing the work a license board does elsewhere. The five checks that substitute for a license lookup, and the sourcing behind the no-license fact, are on the hiring a roofer in a no-license state guide.
One state requirement rides on the contract itself. RSA 359-G:7, read at the statute on 2026-08-25, says at paragraph I: "Upon entering into a purchase agreement or contract for the construction or improvement of a residence in which the contract amount exceeds $5,000, the contractor shall provide written notice to the owner of the residence of the contractor's right to resolve alleged construction defects before a homeowner may commence litigation against the contractor. Such notice shall be conspicuous and may be included as part of the contract." The wording the statute sets out tells the owner that "SIXTY DAYS BEFORE YOU FILE YOUR LAWSUIT OR OTHER ACTION, YOU MUST SERVE ON THE CONTRACTOR A WRITTEN NOTICE OF ANY CONSTRUCTION CONDITIONS YOU ALLEGE ARE DEFECTIVE." The trigger is the contract amount, so ask for that notice on any job priced above $5,000. The statute says nothing about what follows if it is missing, and neither does this page; a lawyer answers that one.
How the replacement project runs
- Inspection and measurement, on the roof rather than from an aerial image.
- A written, itemized estimate naming the panel system, gauge, finish, and a per-sheet decking price.
- Contract signing. On jobs over $5,000, the RSA 359-G notice above belongs in it.
- Panel fabrication lead time; many installers roll-form panels to length for your roof.
- Tear-off (or over-shingle prep), deck repairs, ice and water barrier at eaves and valleys, underlayment.
- Panel installation, flashing, ridge venting, and trim; snow retention goes on last.
- Final walkthrough, warranty registration, and paid-invoice paperwork you keep with the house.
Replace or repair? What the inspection decides
The inspection decides it, not the phone call. An asphalt roof losing granules everywhere is done and the conversion is the honest answer. An existing metal roof with one leak, a flashing gap, or fastener back-out usually wants a repair visit first; see metal roof repair. When the same failures show up across the whole field rather than in one place, repair stops being the cheaper path and the replacement math starts to win. The decision framework, the snow loads, and the contractor checks all live in the New Hampshire Metal Roofing Guide.
Where we cover metal roof replacement projects
Statewide, with the deepest demand in the shingle-heavy suburbs: Manchester and Nashua, metal roofing contractors in Salem and Derry, and the metal roofing contractors in Concord, where thousands of 1980s and 1990s asphalt roofs are aging out at the same time. The valley is the busiest of those markets, so the credential checks and the local snow numbers live on their own page: metal roofing installers in Manchester and Nashua. Outside those markets the same free quote runs through metal roofing contractors in New Hampshire, statewide.
Sources on this page were read at their sources on 2026-08-25: RSA 155-A:1 and RSA 155-A:2 at the New Hampshire statutes, and the reroofing provisions of New Hampshire's three adopted roof codes, residential Section R908, existing building Sections 705 and 706, and building code Section 1512, at the state-adopted code text. RSA 359-G:7, InterNACHI's metal roof inspection course material, and the three national cost guides were read on 2026-08-20 and are unchanged.