On this coast the first thing to check on a bundle of shingles is not the color. It is the wind class printed on the wrapper. Here is what each rating means, what the towns require, and the details that keep shingles down.
Asphalt shingles are the covering the local permit papers spend the most words on. The City of Charleston names a shingle rating on its roofing guideline, Folly Beach spells out the test results it wants, and Goose Creek has owners sign a shingle affidavit. The reason is simple: a shingle that lifts in a tropical storm peels the next row with it and opens the deck to rain.
This page goes through the shingle choice the way an inspector would: the wind rating the code ties to your design speed, what the City of Charleston, Folly Beach, Goose Creek and Summerville each ask for, the layers under the shingles, the nails and what salt air changes about them, the kinds of shingle on the market, why the seal strip matters, the dark streaks humidity brings, and what the historic boards will and will not accept.
Shingles are tested for wind two ways. ASTM D7158 sorts them into Class D, G or H; ASTM D3161 into Class A, D or F. Table R905.2.4.1 of the residential code South Carolina enforces says which classes may be used at which design wind speed:
| Ultimate design wind speed | Basic speed (Vasd) | ASTM D7158 | ASTM D3161 |
|---|---|---|---|
| 110 to 116 mph | 85 to 90 mph | D, G or H | A, D or F |
| 129 mph | 100 mph | G or H | A, D or F |
| 142 mph | 110 mph | G or H | F |
| 155 mph | 120 mph | G or H | F |
| 168 mph and up | 130 mph and up | H | F |
The table's footnote assumes a building no taller than 60 feet in Exposure B or C. FEMA's coastal fact sheet on shingles in high-wind regions is blunter about the tests: it says the D3161 fan test does not tell you enough, and points instead to UL 2390, whose classes carry the same letters as D7158: D for 90 mph, G for 120 mph and H for 150 mph. Its rule is to pick a class at or above the basic wind speed your code sets.
Design wind here runs from 133 to 150 mph depending on the address, and the towns put their shingle rules in writing:
The IBHS FORTIFIED Roof standard asks for the top ratings only: Class F or Class H. If two shingle lines are close in price, the higher class buys margin for very little. The hurricane roof protection page covers FORTIFIED in more detail.
The code sets a floor under the shingles too. Section R905.2.2 keeps asphalt shingles off any roof flatter than 2:12, and between 2:12 and 4:12 they go over a doubled underlayment. Where wind design is required, the application table (R905.1.1(2)) asks for that doubled method at every pitch: a 19-inch starter strip of underlayment along the eave, then 36-inch sheets overlapping by 19 inches. Charleston County has the roofer sign a form saying which of the allowed methods went on; the roof replacement page walks through it.
The drawing below numbers the parts of the shingle roof we put on. Two of them work differently here than the code minimum suggests. South Carolina rewrote the drip edge rule, and the state's version asks for drip edge on a shingle roof only when the shingle's own maker does (R905.2.8.5). We install it on every eave and rake regardless. And the City of Charleston's design table says no ice barrier is required, which is right for ice; we still put self-sealing membrane at the eaves and in the valleys, where wind-driven water finds a roof first.
Section R905.2.5 calls for galvanized steel, stainless steel, aluminum or copper roofing nails with at least a 12-gauge shank and a 3/8-inch head, long enough to go 3/4 inch into the deck or through it. Section R905.2.6 sets the count: whatever the shingle maker requires, and never fewer than four per strip shingle. Goose Creek's affidavit adds the maker's high-wind nailing pattern to that.
FEMA's coastal fact sheet goes further on three points:
Its installation drawing shows six nails per shingle, and six is what we use on every shingle roof, against a code minimum of four.
Three kinds of shingle show up on quotes here:
FEMA also says to use fiberglass-reinforced shingles in warm coastal climates, because organic-reinforced shingles tend to break down faster in heat and have limited fire resistance. On durability, the fact sheet warns that ratings are not standardized from one maker to the next, and that a longer manufacturer warranty, such as 30 years against 20, should come with a more durable shingle. Compare warranty terms line by line, not the headline number.
A shingle's wind rating assumes its adhesive strip has bonded to the shingle below. Until it does, each tab is held only by its nails. FEMA's fact sheet says to inspect the roof after the shingles have had enough sunshine to activate the sealant and to confirm the tabs have sealed, and to use interlocking shingles if a product has no seal strip at all.
Its enhanced details target the places wind gets under a roof first:
If a roof goes on just before a storm and the strips have not sealed, those tabs are the first to go. That is a good reason to look at your roof again a few weeks after a replacement, and we send finished photos so you have a baseline.
Those dark stripes running down a slope are usually alive. ARMA, the shingle industry's trade group, points to an alga called Gloeocapsa magma as the main culprit among several, and says it does best where roofs sit in warm, humid weather, which describes most summers here. Its bulletin treats the stripes as discoloration.
What to do about it:
Curling, cracking, bare spots and lifted tabs are what tell you a roof is near its end, not the color; see roof inspection for what we look at.
Shingles are where the historic boards here disagree most with each other:
It depends on the address. The City of Charleston asks for Type H shingles unless something else is specified, Folly Beach wants Class H or Class F for its 150 mph rating, and Goose Creek accepts Class G or H, or Class F. The code table ties each class to a design wind speed.
They come from two different tests. Class F is the top class of ASTM D3161, a fan test; Class H is the top class of ASTM D7158, an uplift test. The code accepts either at the highest wind speeds, and FEMA puts more weight on the uplift method.
The code accepts galvanized, stainless, aluminum or copper roofing nails. FEMA's coastal guidance recommends stainless steel nails for buildings within 3,000 feet of saltwater, so near the harbor, the beach or a tidal creek, measure the distance before you choose.
The streaks are usually algae, which thrives in warm, humid weather. The roofing manufacturers' association suggests a bleach and water solution mixed to the shingle maker's directions, and warns against power washers, brushes and brooms on the roof.
It depends on the town. Charleston's Board of Architectural Review counts asphalt as inappropriate on historic buildings, though staff approve shingle-for-shingle replacements. McClellanville accepts asphalt on every building, and Summerville prefers heavyweight architectural shingles. Check the town page before you choose.
Only if the maker of your shingles requires it; South Carolina replaced the model code's rule with that one. Read the installation instructions for the shingle on your quote. We install drip edge at every eave and rake on the roofs we replace.
Roof shingles across greater Charleston, from the sea islands and beach towns to Summerville, Goose Creek and Moncks Corner. Each city has its own page with the permit rule and code edition that apply there:
Sources: 2021 International Residential Code as adopted in South Carolina, Chapter 9: Table R905.1.1(2), R905.2.2, Table R905.2.4.1, R905.2.5, R905.2.6, R905.2.8.5 (UpCodes) · FEMA, Home Builder's Guide to Coastal Construction, Technical Fact Sheet 7.3, Asphalt Shingle Roofing for High Wind Regions (copy posted by the City of Goose Creek) · City of Goose Creek, Asphalt Shingle Roofing / Re-Roofing Affidavit · City of Charleston, roof permit guideline (Type H shingles) · City of Charleston design criteria table (150 mph, ice barrier: no) · City of Folly Beach, 2026 permit packet (Class H or Class F) · Town of Summerville, Building Code Requirements (shingle table) · IBHS FORTIFIED, FORTIFIED Roof · Asphalt Roofing Manufacturers Association, Algae Discoloration of Roofs · City of Charleston, Board of Architectural Review · Town of Summerville, Historic District Design Guidelines · Town of McClellanville, Historic District Design Review Manual · Town of Mount Pleasant, Old Village Historic District Guidelines · Town of Rockville, Design Review Board · Town of Sullivan's Island, Historic District Design Guidelines, Chapter 4. Codes, programs and prices change; confirm the current rule with your city before you rely on it.
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