Do I need a permit for roof replacement in
Dover, New Hampshire?

Dover roof replacement permits — the key details

Dover Building Department enforces Chapter 3 of the 2015 IBC and articles of the 2015 IRC as adopted by the State of New Hampshire, with local amendments specific to snow and ice loading, wind exposure, and three-layer tear-off mandate. The threshold for a required permit is straightforward: any full roof replacement, any tear-off-and-replace operation, any material change (shingles to metal, composition to slate, etc.), or repairs exceeding 25% of the total roof area by square footage require a permit application. IRC R907.4 explicitly mandates complete removal of all existing roof covering if three or more layers are present; Dover inspectors perform layer-count verification during the pre-permit site visit or via photo submission. Permits for straightforward re-roofing (same material, no decking repair) are handled over-the-counter and cost $150–$350 depending on total roof area; the fee is typically calculated at $3–$5 per 100 square feet of roof deck. The permit application itself requires the contractor (or owner-builder, if you're doing the work yourself on your primary residence) to submit a completed roofing specification form that includes material type, underlayment grade, fastening pattern per manufacturer spec, ice-and-water shield extent, and flashing details.

New Hampshire's Climate Zone 6A classification means ice-and-water shield (self-adhering underlayment) must extend a minimum of 24 inches up the roof plane from the eaves and around all roof penetrations (chimneys, vents, skylights); Dover inspectors will cite missing or inadequately extended ice-and-water shield as a code violation during the in-progress deck inspection. Furthermore, because Dover sits in a moderate-wind and moderate-snow region, the code requires 6-inch laps on all felt underlayment or synthetic replacement, mechanical fastening of underlayment per the underlayment manufacturer's specifications (not the shingle manufacturer alone), and full-length flashing boots on all vents and pipes. The three-layer rule is a strict application in Dover: if a visual inspection or photos reveal three existing layers, you cannot overlay a fourth layer under any circumstance — tear-off is legally mandated. This is a common surprise for homeowners who assume they can simply nail over old shingles; Dover Building Department has clarified in their FAQ (available on the city website) that the 3-layer threshold is tied to structural safety and wind-uplift load paths, not just code pedantry. Many contractors will do a field probe (nail pop or shingle lift to visually confirm layer count) on-site at no cost; if you're unsure, request this before committing to a bid.

Exemptions from permit requirements in Dover are narrowly scoped. Repairs under 25% of roof area using like-for-like material (composition shingles replaced with composition shingles, same color family), with no decking work, no re-flashing, and no change to the roof's structural load path, do not require a permit. However, 'repair' is defined strictly: patching a few missing shingles after a storm, replacing a single section of damaged flashing, or tar-patching a leak are repairs; adding a new layer of shingles or doing anything that requires tearing off old material is considered reroofing and requires a permit regardless of area. Gutter and downspout work, skylight installation, or chimney flashing replacement may be permitted under a separate category (exterior structural work) and should be confirmed with the building department if bundled with a roof project. The key test: if your work requires the contractor to remove old material, it needs a permit. If the work is done entirely on top of or in place of existing material without removing substrate, it's a repair and exempt. Owner-builder exception: If you own a single-family, owner-occupied home in Dover, you may pull a permit as an owner-builder for reroofing work without hiring a licensed roofing contractor; however, the work must still pass all inspections, and the City may require a third-party inspection agency if structural concerns arise.

The permit application and inspection sequence in Dover typically follows this timeline: Day 1, submit application online or in-person with completed roofing spec form, photos of existing roof/layers, and property card. Day 1–2, over-the-counter issuance for standard re-roofs. Day of work (or prior), notify building department; inspectors will schedule the in-progress deck inspection after tear-off is complete and before new underlayment is laid. This deck inspection verifies nailing pattern of any new decking repair, condition of existing deck, and water-intrusion signs. After roofing is substantially complete (underlayment down, shingles 80% applied), call for the final inspection; the inspector will verify ice-and-water shield extent, flashing detail compliance, fastening pattern spot-check, and general workmanship. Total permit timeline is typically 1–3 weeks from application to final sign-off, with the bulk of time spent waiting for inspection scheduling (especially in spring/fall when roofing activity peaks). If you're changing material to metal or slate, plan for 2–3 additional weeks of engineering review to verify deck load capacity; Dover Building Department will request a structural calculation or engineer's letter if the new material is significantly heavier than the old.

Cost and contractor responsibility: permit fees in Dover range from $150 to $350 depending on roof area; the contractor pulling the permit typically passes this cost through to you, or you may pull it yourself if owner-building. Material costs are not included in the permit fee calculation. The contractor is responsible for confirming that the roofing product being used meets or exceeds the shingle uplift rating required by the 2015 IBC for New Hampshire Zone 6A (typically 130 mph wind rating minimum for composition shingles, which is standard). If you're upgrading to a metal roof, stone-coated steel, or architectural shingles, verify that the contractor specifies the correct fastening pattern (often longer and more frequent fasteners than standard shingles) and that the deck is evaluated for the new load. Many homeowners do not realize that metal roofing, while durable, can require reinforcing of certain roof framing members if the deck was originally designed for composition shingles and the new metal is significantly stiffer; Dover inspectors may flag this and require engineer review, which can delay approval by 1–2 weeks and cost $300–$800 for a third-party structural assessment.

Three Dover roof replacement scenarios

Ice-and-water shield requirements in Dover's Climate Zone 6A

Dover sits in ASHRAE Climate Zone 6A, characterized by cold winters, heavy snowfall (average 60+ inches per season), and freeze-thaw cycling that creates ice dams at roof eaves. Ice dams form when warm air from the attic melts snow on the upper roof, the meltwater runs down to the unheated eaves, refreezes, and backs up water under the shingles — this water intrusion can cause interior damage, structural rot, and mold within weeks. To combat this, the 2015 IRC and Dover's local adoption mandate ice-and-water shield (self-adhering, rubberized asphalt underlayment) on all sloped roofs in Zone 6A.

Specifically, ice-and-water shield must extend a minimum of 24 inches up the roof plane from the exterior wall line (the eave), covering the entire eave width. If the roof overhangs more than 16 inches, the shield must extend the full overhang plus 24 inches up the slope. Around all roof penetrations (chimney, vent pipes, skylights), ice-and-water shield must extend a minimum of 12 inches up the slope and 12 inches on all horizontal sides of the penetration. Valleys must be underlaid with ice-and-water shield extending 12 inches on each side of the valley centerline. Dover inspectors will measure ice-and-water shield extent during the final inspection and will cite missing or under-extended shield as a code violation, delaying sign-off until corrected.

The reason this is non-negotiable: Dover's 48-inch frost depth means the ground stays frozen until late April, which keeps attic temperatures near-freezing even on warm late-winter days. Poorly installed underlayment or inadequate ice-and-water shield leaves your home vulnerable to expensive water damage ($10,000–$30,000 for structural rot, interior renovation, and potential mold remediation). Many homeowners and even some contractors underestimate this requirement, assuming standard felt underlayment is sufficient. It is not. Synthetic underlayment alone (without ice-and-water shield) does not meet code. Dover Building Department has fielded multiple claims of water intrusion on homes that were permitted and inspected with inadequate ice-and-water shield, so inspectors are vigilant on this point and may measure the shield with a tape or review installer photos before issuing final approval.

The three-layer mandate and why Dover enforces it strictly

IRC Section R907.4 states: 'Roof coverings shall not be installed over existing wood shake, slate, asbestos-cement, clay or concrete tile, or slate roof coverings. An underlayment shall be applied in a single layer directly to the top of the existing roof covering.' The rule is more specific: 'When an existing roof covering is replaced, the new roof covering shall be installed in accordance with Section R905 (re-roofing requirements). Where the existing roof covering cannot be determined to be two layers or fewer, the existing roof covering shall be removed before applying a new roof covering.' Dover interprets 'cannot be determined to be two layers or fewer' as: if you see three or more layers via field inspection, complete tear-off is mandatory.

Why? The concern is wind uplift and structural load path. A roof with three layers has higher mass, altered nailing patterns (nails from the first layer protrude or are buried beneath two subsequent layers), and unpredictable fastening geometry. Wind resistance testing by IBC researchers shows that roofs with hidden or poorly-secured base layers experience premature failure under high wind loads (typically 90+ mph). Dover's 48-inch frost depth and seasonal ice buildup also increase dead load on the roof structure; compounding this with an unknown three-layer nailing pattern is a safety liability. Therefore, Dover Building Department requires a visual field inspection (roof probe, shingle lift, or photos) before permit issuance to establish layer count.

In practice: the contractor or property owner submits photos showing exposed roof layers, or the contractor visits the site and takes a nail probe photo showing cross-section of layers, and submits this with the permit application. If three layers are discovered after work has begun, the contractor must stop, file an amended permit for tear-off, and invoice the homeowner for the additional removal cost (typically $1,500–$3,000 for tear-off labor and disposal). This is a financial shock many homeowners don't anticipate, so confirm layer count early. If you're unsure, hire the contractor to do a field probe before you sign a contract; most charge $0–$200 for this service and it saves surprises.

Common questions