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Metal roofing in Sterling, VA: what the code says about putting panels over shingles
Loudoun County's permit pages never mention metal. The rules that do sit in the Virginia Residential Code, which Virginia's building regulations adopt for houses and townhouses. This page reads its roof recover section and its underlayment table for metal panels, says where each is silent, and lists what to ask the county and a roofer before any panel goes on a Sterling roof.
- Three listed conditions bar any recover over an old roof
- Standing seam panels: minimum slope 1/4 unit in 12
- State exemption stops at a 100 mph design wind speed
Figures from the 2021 Virginia Residential Code chapter 9 as published by UpCodes, 13VAC5-63-80 and Loudoun's permit page, all read on October 19, 2026.
Which office and which code book
Sterling has no town government, so Loudoun's Department of Building and Development is the one permit office. The state's Uniform Statewide Building Code adopts the 2021 International Residential Code, and its note says that book applies to detached one-family and two-family homes and townhouses. Larger buildings fall under a different volume of the code, which this page did not read, so an apartment or condominium building is a county question from the start. The wider Sterling picture, housing mix and weather record are on our Sterling guide.
The permit regulation also has a scope clause. It says the state code supersedes local ordinances for single-family construction that require specific building materials or finishes, and then lists what it does not supersede: rezoning conditions, special exceptions, variances, and land use requirements in airport or highway overlay districts, historic districts and floodplain rules.
The recover clause, step by step
Replacement (R908.3)
Removes every existing layer of covering down to the roof deck. The one exception lets an adhered ice barrier stay and take another layer on top.
Recover (R908.3.1)
Puts a new covering over the old one. It is allowed only under the listed conditions, and R908.3.1.1 then names three situations where it is not allowed at all.
A homeowner asking about metal over shingles is asking a recover question. The section reads as a sequence, and the order below follows its logic.
- Check the three bars first. A recover is not permitted where the old roof or covering is water soaked or so deteriorated it is not an adequate base, where the old covering is slate, clay, cement or asbestos-cement tile, or where the roof already has two or more applications of any covering.
- Confirm the manufacturer's approved instructions allow it. The first listed condition is that the new covering is installed under the covering manufacturer's approved instructions. The code does not say what those instructions contain.
- Ask whether the system is "complete and separate". The code names standing seam systems designed to carry roof loads straight to the building's structure without relying on the old roof for support.
- Ask about the structure. R908.2 says the roof structure must carry the new system plus the material and equipment loads met during installation. Neither source says who calculates that for a house.
"shall not require the removal of existing roof coverings"
2021 Virginia Residential Code, R908.3.1, on complete and separate roofing systemsThe sentence above sits in the list of conditions that permit a recover. The text read does not say whether it overrides the three bars in R908.3.1.1, and it does not say whether a panel fastened through old shingles to the deck counts as complete and separate. Those are questions for the county's plan reviewer, with the manufacturer's installation sheet in hand.
What the Metal Construction Association says
The Metal Construction Association's consumer page says metal roofs "can often be installed over an existing roof" and so avoid tear-off. Its retrofit page describes light-gauge sub-framing systems for existing flat, low-slope and metal roofs and lists commercial, industrial, education and retail buildings as the uses. Neither page mentions asphalt shingles or Virginia's code, and both are trade descriptions, not rules. The word "often" matters: the code's three bars decide the cases where it is not possible.
Does a recover need a permit?
State regulation 13VAC5-63-80 exempts replacing an unlimited amount of roof covering in groups R-3, R-4 and R-5, as long as the building is not in an area with a nominal design wind speed above 100 miles per hour, and exempts replacing 100 square feet or less in any group. The same list exempts replacing 256 square feet or less of decking in those groups, unless the decking had to be fire-retardant-treated or form a fire-rated wall termination. The word used is replacement. Whether a recover counts, and which wind speed applies to a Sterling address, are not answered by the county pages read here.
Underlayment under metal panels
Section R905.10.5 is one sentence: underlayment shall comply with R905.1.1. The detail lives in that section and its tables.
- Where wind design is not required
- Table R905.1.1(1) says, for metal panels, to follow the manufacturer's instructions. The wind design question is set by Figure R301.2.1.1 in the code.
- Where wind design is required
- The table asks for ASTM D226 Type II, or ASTM D4869 Type III or IV, under metal panels.
- Labels
- Products made to ASTM D226, D1970, D4869 and D6757 must carry a label showing compliance and, where it applies, the type.
- Self-adhering option
- A self-adhering polymer-modified bitumen underlayment labeled to ASTM D1970 is permitted if installed to both the underlayment maker's and the covering maker's instructions.
- Deck joint strip option
- A strip of that membrane at least 4 inches wide over all deck joints, plus an approved underlayment across the whole roof, is the other listed alternative.
Two facts shape the recover case. R905.10.1 says metal panels go on solid or spaced sheathing, unless the product is designed for spaced supports, and the underlayment sections are written around a deck. The chapter does not say where an underlayment layer goes when panels are laid over an existing roof covering, or whether the old shingles can serve. Second, the ice barrier section lists metal roof shingles but not metal roof panels, and applies only where the locality's design table designates a history of ice at the eaves.
| Code item | What it sets | Ask about |
|---|---|---|
| R905.10.2 slope | 3 in 12 for lapped seams without sealant; one half in 12 with applied lap sealant; one quarter in 12 for standing seam | Your measured pitch against the profile |
| R908.1 exception | Reroofing need not meet the one quarter in 12 floor where the roof has positive drainage | Whether your roof drains positively |
| R905.10.3 materials | Named standards by metal, for example ASTM A653 G90 galvanized steel; aluminum roll-formed panels at 0.024 inch minimum | The product data sheet's standard and coating |
| R905.10.4 fasteners | Galvanized for steel roofs when manufacturer's instructions are absent; stainless acceptable | The fastener type on the written scope |
Source: 2021 Virginia Residential Code chapter 9 (UpCodes copy, October 19, 2026; the ICC copy refused automated access).
What neither source settles
Loudoun's pages
The permit list names additions, decks, renovations and similar work. It does not name roofs, metal or recovers. The Permitting page tells applicants to contact their homeowner or property owner association. A county page that stays quiet is not a ruling on your scope.
Fire classification
Section R902.1 requires Class A, B or C roofing where the law designates it or where the roof edge is less than 3 feet from a lot line, tested to ASTM E108 or UL 790. It lists metal sheets and shingles on noncombustible decks as Class A. For a townhouse roof near a property line, the assembly's listing is worth asking for.
Questions before a panel order
- Is the existing roof one layer, dry, and sound enough to count as an adequate base?
- Which section of the manufacturer's approved instructions allows installation over an existing covering?
- Does the county treat a recover as covered by the state exemption, and for which wind speed?
- Where does the underlayment go, and which ASTM type or label does the scope name?
- Who checks the roof structure under R908.2, and is it in writing?
- What does the association require, and does the approval come before the order?
Roofers of Arlington installs, repairs and replaces roofs, including flat and metal systems. Book a phone consultation to talk through a Sterling metal roof: we would ask your address, the building type, the pitch if known, what covers the roof now and what is visible from the ground. Compare coverings on materials, see roof replacement and services, or return to the Sterling guide. Arlington's own rules differ, as the Arlington hub shows.
Code and county pages read, with dates
All pages opened October 19, 2026.
- Virginia Residential Code 2021, chapter 9 Roof Assemblies (UpCodes copy)
- 13VAC5-63-10, 13VAC5-63-20 and 13VAC5-63-80, Virginia Uniform Statewide Building Code
- Metal Construction Association: Types of Metal Roofing and Retrofit
- Loudoun County: Permitting and Residential and Commercial Construction Permits
Questions people ask
Can a metal roof go over existing shingles in Virginia?
The 2021 Virginia Residential Code lets a new covering go over an old one only where its list of conditions is met, and it bars a recover where the old roof is water soaked, is tile or slate, or already has two or more coverings. It names standing seam systems that do not rely on the old roof for support as not needing removal. Confirm your system with Loudoun Building and Development.
Does Loudoun County list metal roofs on its permit pages?
No. The residential permit list on the county's Residential and Commercial Construction Permits page names additions, decks and similar work, and does not name roofs or any roof material. Ask the county, on 703-777-0220, which path applies to your scope.
What is the minimum slope for a standing seam roof in the code?
The Virginia Residential Code sets a floor of one quarter unit vertical in 12 horizontal for standing seam systems. Lapped, nonsoldered seam panels need 3 in 12, or one half in 12 with applied lap sealant. A reroof over a roof with positive drainage is excused from the one quarter in 12 floor.
What underlayment does the code require under metal panels?
Section R905.10.5 sends metal panels to the general underlayment section. Its table says to follow the manufacturer's instructions where wind design is not required, and ASTM D226 Type II or ASTM D4869 Type III or IV where it is. Which case applies to a Sterling address is a county question.
Is a metal panel roof a Class A roof?
The code's fire classification section says Class A assemblies include metal sheets and shingles installed on noncombustible decks. It does not name wood decks in that sentence, so ask for the tested classification of the whole assembly, which the section ties to ASTM E108 or UL 790 testing.
Does the state permit exemption cover a metal re-roof?
The state exemption covers replacing an unlimited amount of roof covering in groups R-3, R-4 and R-5 unless the design wind speed is above 100 mph. It does not say whether a recover counts as replacement, and Loudoun's pages are silent, so get the answer in writing before work starts.
Does the state code override a Sterling association on roof materials?
The state regulation supersedes certain local ordinances that require specific materials in single-family construction. Its text speaks of local ordinances and says nothing about association covenants, so read your recorded declaration and ask the association; for legal questions, ask an attorney.
Do metal roof panels need an ice barrier in the code?
The ice barrier section lists metal roof shingles but not metal roof panels, and applies only where the locality's design table designates a history of ice at the eaves. The sources read here do not show Loudoun's designation, so ask the county.
Talk through your roof with Roofers of Arlington
Share the address, what you are seeing on the roof and the decision you need to make. We will tell you what to expect before anything is scheduled.