Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Full roof replacements, tear-offs, material changes, and work covering more than 25% of roof area require a permit from the City of St. Marys Building Department. Like-for-like repairs under 25% may be exempt.
St. Marys enforces Georgia state building code (International Building Code via Georgia Code § 43-1), which requires permits for reroofing projects under IRC R907. The City of St. Marys Building Department handles permitting in-house and does NOT have a dedicated online portal for roof permits — you must file in person at City Hall or by phone/email to confirm current filing method. This differs from nearby larger jurisdictions (like Camden County unincorporated areas) which may have partial online filing. St. Marys' permit fees typically run $150–$400 depending on roof square footage and are assessed as a percentage of estimated project cost (usually 1.5–2%). The city is in warm-humid climate zone 3A with 12-inch frost depth, which means ice-and-water shield requirements in IRC R905.2.8 apply to roof valleys and eaves if you're upgrading materials. Tear-off-and-replace work always requires a permit and inspections; overlay (new shingles over old) may qualify for exemption if you're under 2 existing layers and staying with the same material, but you must confirm with the building department before starting work.

What happens if you skip the permit (and you needed one)

St. Marys roof replacement permits — the key details

St. Marys enforces the International Building Code (IBC) through Georgia's state adoption and implements IRC R907 (Reroofing) as the primary standard. Per IRC R907.1, any roof covering replacement is considered reroofing and requires a permit unless the work falls into a narrow exemption category. The two most important thresholds: (1) any tear-off-and-replace work always requires a permit and two inspections (deck and final); (2) overlay work (new shingles fastened over existing) is only exempt if you have fewer than two existing layers and are using the same material type. If your roof already has two layers of shingles or asphalt, you must tear off before installing a new one — this is non-negotiable under IRC R907.4 and is not a local preference, but St. Marys enforces it strictly. The City of St. Marys Building Department does not maintain a public online permit portal like some larger Georgia cities (Atlanta, Savannah) — you must contact them directly by phone or visit City Hall in person to file. This means timelines are slightly longer (3–5 business days for intake vs. immediate online submission), so plan accordingly.

Material changes trigger additional code review. If you're replacing asphalt shingles with metal, tile, or slate, IRC R905 requires the City of St. Marys to review the installation spec, flashing design, and (for tile/slate) structural adequacy of the existing roof framing. Metal roofs are increasingly popular in St. Marys due to longevity in the warm-humid climate, but they require different fastening patterns, underlayment specifications, and valley detailing than asphalt. Permit applications for material changes should include a spec sheet from your contractor or the roofing manufacturer showing fastener type, spacing, underlayment R-value, and ice-and-water shield extent (required per IRC R905.2.8 in valleys and 24 inches from eaves on sloped roofs). St. Marys does not have a local amendment exempting material-change reroofs — all such work requires full permit review and inspections. Underestimating the scope of work on your permit application (e.g., listing 10 squares but actually doing 15) is a common rejection reason; be honest about square footage and include a simple sketch or satellite photo with dimensions.

Tear-off work is the most common compliance issue in St. Marys. Before your contractor starts removing the old roof, the permit must be issued and a pre-work (deck inspection) scheduled. The inspector will verify that the existing roof deck (plywood or skip-sheathing) is solid, that any water damage from prior leaks has been repaired, and that fastener schedules for the new installation are clearly marked or available. If deck damage is discovered during tear-off, your contractor must stop work and request a permit amendment for the repair scope — this delays your timeline by 3–7 days. Asbestos-containing roofing materials (common in homes built before 1980) may trigger additional environmental review; if your house was built before 1980 and you're tearing off, ask your contractor or the City of St. Marys Building Department whether asbestos testing is required. Most St. Marys homes with asbestos roofing can be handled under standard building-debris protocols, but you must disclose it on the permit application.

Inspection timing and final approval depend on permitting method. If you file in person at City Hall (the standard for St. Marys), expect 2–3 business days for permit issuance. Once issued, the inspector must be called for the pre-work (deck) inspection before tear-off begins — this typically occurs within 1–2 business days of notification. Tear-off can then proceed. After new roof installation is complete (usually 1–3 days for a typical residential roof), you schedule the final inspection, which focuses on fastening patterns (spacing and type per IRC R905), underlayment adhesion, flashing at valleys/rakes/hips, and proper overhang. The final inspection pass allows your contractor to invoice; the City of St. Marys usually issues a Certificate of Completion within 1 business day. Total timeline from permit filing to final approval is typically 10–15 business days for straightforward like-for-like replacements, longer if deck repair is needed.

St. Marys is in warm-humid climate zone 3A with 12-inch frost depth, which affects underlayment and flashing specs. Ice-and-water shield (synthetic underlayment) must extend from the eave edge to 24 inches up the slope on all pitched roofs per IRC R905.2.8, even though St. Marys rarely freezes. This protects against wind-driven rain and condensation in the warm season. Flashing around pipes and roof penetrations must be metal (no plastic) and sealed with roofing cement or compatible sealant — this is an inspection point. Additionally, St. Marys experiences occasional tropical-storm-force winds and high humidity, so contractor selection is critical; verify your roofer holds a Georgia roofing license (CSLB-equivalent) and carries adequate liability insurance ($1–2 million). The City of St. Marys Building Department may request proof of contractor licensing on the permit application.

Three St. Marys roof replacement scenarios

Scenario A
Like-for-like asphalt shingle overlay, single existing layer, 1,800 sq. ft. single-story ranch home
You have a 1970s ranch in St. Marys with a single layer of weathered asphalt shingles and want to install new asphalt shingles over the existing (overlay). This project qualifies for potential exemption under IRC R907.2(a) if the existing deck is sound, you're using the same material type, and you have only one existing layer. However, St. Marys requires you to confirm exemption status with the Building Department before starting — don't assume. Call City Hall (St. Marys Building Department) and provide a photo of the existing roof and a description of your plan. If approved, you may proceed without a permit, but this is rare in practice because most roofers prefer to pull a permit anyway to protect their liability (and yours). If you do pull a permit for this overlay, the cost is $150–$250 (based on 1,800 sq. ft. ÷ 100 = 18 squares × ~1.5% of estimated $6,000–$8,000 project cost). Inspections are minimal — deck inspection to verify no soft spots, and final to confirm fastening and flashing. Timeline is 7–10 days from filing to final approval. If the inspector finds a second hidden layer during tear-down (sometimes discovered mid-work), you'll be required to stop, obtain a permit amendment for full tear-off, and restart. This adds 5–7 days and another $100–$150 in fees.
Overlay on single layer, same material | Possible exemption—confirm with City first | Permit $150–$250 if required | Two inspections (deck, final) | 7–10 day timeline | New GAF or CertainTeed 25-year shingles $6,000–$8,000 total
Scenario B
Tear-off and metal roof replacement, two existing layers, material upgrade, 2,200 sq. ft. two-story colonial
Your two-story colonial in St. Marys has two layers of asphalt shingles and you want to upgrade to a metal (standing-seam) roof for durability in the warm-humid climate. This is a mandatory-permit project under IRC R907.4 (second layer triggers tear-off requirement) and IRC R905 (material change). You must file a formal permit application with the City of St. Marys Building Department in person at City Hall, including the contractor's spec sheet for the metal roof system (fastener type, spacing, underlayment R-value, sealant type, and ice-and-water shield extent). Cost estimate: $18,000–$24,000 for the metal roof installation; permit fee is typically 1.5–2% of project valuation, so $270–$480. Permit issuance takes 3–5 business days (the city reviews metal-roof flashing and fastening details). Once issued, the contractor calls for a pre-work deck inspection (1–2 days out). Tear-off begins immediately after; this takes 2–3 days depending on roof pitch and weather. During tear-off, if the inspector finds water damage to the deck or a hidden third layer, work stops and a permit amendment is required (adds 3–5 days). Assuming sound deck, the new metal roof installation takes 3–5 days. Final inspection focuses on fastener spacing, underlayment overlap, valley flashing, and sealant compliance. Total timeline: 15–25 business days. Metal roofs are popular in St. Marys but require contractor experience — verify your roofer has completed at least five metal-roof projects in the region and holds a current Georgia roofing license.
Tear-off required (2 existing layers) | Material change: asphalt to metal | Permit $270–$480 | 3–5 day intake, 2–3 day tear-off, 3–5 day install | Spec sheet required (fastener, underlayment, sealant) | Pre-work and final inspections | Metal roof total $18,000–$24,000 | 15–25 business day timeline
Scenario C
Partial roof replacement (storm damage repair), 12% of roof area, asphalt shingles, 35% of roof is new, Craftsman bungalow
A summer storm blew off shingles on the southeast-facing slope of your 1920s Craftsman bungalow in St. Marys. The damage affects roughly 150 sq. ft. of the 1,500-sq.-ft. roof (10% damage). You patch it with matching shingles, tying in the new course to the existing shingles on either side. Under IRC R907.3, repairs to less than 25% of roof area using the same material type are exempt from permitting if you're not doing a tear-off (just removing damaged shingles, replacing plywood if soft, and fastening new shingles). This repair qualifies for exemption — no permit required. Cost is $800–$1,200 (shingles + labor, no permit fees). However, if the patch area exposes rotten or deteriorated deck (common in warm-humid climates like St. Marys), and your contractor ends up replacing 200 sq. ft. of plywood and 300 sq. ft. of shingles (now 20% of roof), you still remain under 25% and the exemption holds. If damage or cost estimates grow and you expect to exceed 25% coverage, call the City of St. Marys Building Department and pull a permit preemptively ($150–$250) — this protects you and the contractor legally. One nuance: if this is your third storm repair in two years and you're now approaching 25% cumulative work, the city may require a full permit for the next claim — keep records of prior repair permits or exemptions.
Repair under 25% of roof area | Like-for-like asphalt shingles | Exempt from permit | $800–$1,200 (shingles + labor) | No inspections required | If approach 25%, pull permit for documentation | Storm claim coordination with insurance recommended

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Layer detection and tear-off compliance in St. Marys

Underlayment specifications and fastening patterns are the second most frequent inspection fail point in St. Marys. When you upgrade from asphalt to metal, or when wind-damage claims expose original roofing, inspectors verify that the new underlayment meets IRC R905 and that fasteners are placed exactly per the manufacturer's spec and the shingle/panel layout. In warm-humid zone 3A, ice-and-water shield (also called synthetic or rubberized underlayment) must run 24 inches up the slope from every eave, plus full valleys. Asphalt shingles require an underlayment of at least 15 lb felt or synthetic equivalent; metal roofs typically require 30–60 lb felt or a gasketed metal underlayment depending on the system. Your permit application should include the contractor's spec sheet stating product name, weight/R-value, and fastening schedule. If your permit doesn't specify underlayment type, the inspector may reject the final inspection and require a corrective permit. St. Marys does not offer much leniency here — code is code. Your contractor should provide a written spec sheet before work begins; if they don't, ask them to (in writing) or find a different contractor.

St. Marys permit process workflow and timelines

After the pre-work inspection passes, tear-off and installation proceed at the contractor's pace (typically 2–5 days depending on roof size and weather). Once the new roof is complete, the contractor (or you, if owner-builder) calls for a final inspection. The final inspection focuses on fastening, underlayment sealing, flashing at penetrations and valleys, and gutter attachment. This usually takes 1 business day to schedule and 30–60 minutes to perform. If the inspector finds any issues (fasteners missing, underlayment gaps, improper valley fold), the contractor must correct and request a re-inspection (adding 1–3 days). Assuming all passes, the City of St. Marys issues a Certificate of Completion within 1 business day, and you can consider the work done. Total calendar time from permit filing to Certificate of Completion is typically 10–15 business days for straightforward replacements, and 20–30 business days if deck repairs are discovered. Owner-builder permits are allowed under Georgia Code § 43-41 but are rare for roofing because most homeowners prefer contractor liability; if you are owner-builder, you must pull the permit yourself, schedule inspections, and be present during all inspections.

City of St. Marys Building Department
City Hall, St. Marys, Georgia (verify address locally)
Phone: Call City of St. Marys main line and ask for Building Department
Monday–Friday 8 AM–5 PM (local holidays observed)

Common questions

Do I need a permit to replace my roof in St. Marys if I'm just patching a few blown-off shingles?

No, if the repair covers less than 25% of the total roof area and uses the same material type (asphalt-to-asphalt, for example). However, if you discover rotten deck during the repair and end up replacing significant plywood, confirm with the City of St. Marys Building Department that you're still under 25% before proceeding. If you approach 25%, pull a permit to be safe ($150–$250) and protect yourself and your contractor legally.

How much does a roof permit cost in St. Marys?

Typically $150–$400, depending on the project scope and estimated replacement cost. The fee is usually calculated as 1.5–2% of the project valuation. A 2,000-sq.-ft. asphalt shingle replacement (roughly $6,000–$8,000 installed) incurs a permit fee of $150–$250. Material-change projects (asphalt to metal) are on the higher end of this range due to additional code review.

What happens if my roof has three layers of shingles and I want to install new shingles?

You must tear off all existing shingles down to the deck before installing new ones. IRC R907.4 prohibits more than three total layers (i.e., a fourth layer is not allowed). The City of St. Marys inspector will verify layer count during the pre-work inspection. If you're honest about this on your permit application and budget for tear-off, it's straightforward; if a third layer is discovered mid-project, work stops and a permit amendment is required, adding time and cost.

Can I do my own roof replacement in St. Marys without hiring a contractor?

Yes, under Georgia Code § 43-41, owner-builders can pull roofing permits. However, you must pull the permit yourself at the City of St. Marys Building Department, schedule and be present for both inspections, and ensure the work meets IRC R905 and R907. Most homeowners prefer contractor liability; if you choose owner-builder, expect more scrutiny from the inspector and ensure you have adequate liability insurance.

Do I need underlayment under my new roof shingles in St. Marys?

Yes. IRC R905 requires underlayment under all shingles, typically 15 lb felt or synthetic equivalent. In St. Marys' warm-humid climate, ice-and-water shield (synthetic underlayment) must also run 24 inches up the slope from eaves and cover all valleys. Your contractor should specify the underlayment product on the permit application; if they don't, ask them to do so before work begins. The final inspection will verify underlayment compliance.

How long does it take to get a roof permit approved in St. Marys?

Intake at City Hall is usually 1–3 business days. Once issued, the pre-work deck inspection can be scheduled within 1–2 business days. Tear-off and installation take 2–5 days, and the final inspection is scheduled within 1 business day of notification. Total timeline is 10–15 business days for straightforward replacements, longer if deck repair is discovered or if materials are on backorder.

What if I want to switch from asphalt shingles to metal roofing in St. Marys?

A material change requires a full permit under IRC R905. You must include the metal-roof manufacturer's spec sheet on your application, showing fastener type, spacing, underlayment type, and flashing details. The City of St. Marys will review these during intake and may request clarification before issuing the permit. Permit fees are $250–$400 (higher due to additional code review). A pre-work deck inspection is required to verify structural capacity for metal-roof fastening patterns.

What if the City of St. Marys Building Department discovers unpermitted roofing work during a property inspection?

The city can issue a stop-work order (with fines of $300–$500), require you to obtain a retroactive permit (often at double the normal fee, or $300–$800), and may issue a citation. Additionally, unpermitted major work must be disclosed on the Georgia Residential Property Condition Disclosure Statement if you sell; failure to disclose can result in rescission or lawsuit. Insurance claims for unpermitted work may also be denied.

Is St. Marys a hurricane-zone or high-wind area requiring special roof specifications?

St. Marys is in warm-humid climate zone 3A (not a designated hurricane zone requiring FBC 7th or 8th edition high-wind specs). However, the city does experience occasional tropical-storm-force winds. Standard IRC R905 fastening and underlayment rules apply. If you want to upgrade to wind-resistant materials (e.g., architectural shingles rated for 130+ mph or metal roof), the City of St. Marys does not require it but may offer expedited permitting or inspection for projects exceeding baseline code.

Who calls the inspector to schedule the deck and final inspections for my roof permit in St. Marys?

Typically the contractor calls, but if you're owner-builder or the contractor is unresponsive, you can call the City of St. Marys Building Department directly using the inspector's line (ask for the number when you pick up your permit). Inspections are usually scheduled within 1–2 business days of the call. Be present during inspections if possible so you can ask questions and understand any corrections needed.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current roof replacement permit requirements with the City of St. Marys Building Department before starting your project.