Design wind speed by town
Appendix AY assigns each of Connecticut's 169 municipalities an ultimate design wind speed. The statewide spread runs from 115 mph in the northwest hills to 129 mph at the southeastern shoreline.
| Ultimate design wind | Municipalities | Examples |
|---|---|---|
| 115 mph | 21 towns | Barkhamsted; Canaan; Colebrook; Cornwall; Goshen; Hartland; Kent; Litchfield; Morris; New Fairfield; New Hartford; New Milford; Norfolk; North Canaan; Salisbury; Sharon; … |
| 120 mph | 96 towns | Andover; Ansonia; Ashford; Avon; Beacon Falls; Berlin; Bethany; Bethel; Bethlehem; Bloomfield; Bolton; Bridgeport; Bridgewater; Bristol; Brookfield; Burlington; Canton; C… |
| 125 mph | 43 towns | Bozrah; Branford; Brooklyn; Canterbury; Chaplin; Chester; Clinton; Colchester; Columbia; Deep River; East Haddam; East Hampton; East Haven; Essex; Franklin; Griswold; Gui… |
| 126 mph | 4 towns | East Lyme; Ledyard; Old Lyme; Old Saybrook… |
| 127 mph | 3 towns | New London; North Stonington; Waterford… |
| 128 mph | 1 towns | Groton… |
| 129 mph | 1 towns | Stonington… |
Ground snow load by town
Ground snow load runs from 30 psf across most of the state to 40 psf in the northwest corner and part of the northeast.
| Ground snow load | Municipalities |
|---|---|
| 30 psf | 107 towns |
| 35 psf | 44 towns |
| 40 psf | 18 towns |
Ice barrier — required statewide
Two Connecticut amendments matter on almost every job. The first is statewide ice barrier, R905.1.2: from the lowest edge of the roof to a point 24 inches or more inside the exterior wall line, measured on the slope. On a shallow pitch that is a surprising amount of membrane. The second is R905.1.1, the sealed roof deck rule, which has an exception for lumber sheathing of less than 3 inches nominal width — common on older housing stock here.
Nailing: four is code, six is warranty
Four is code, six is warranty. Connecticut's minimum is four nails per shingle; the shingle manufacturers want six before they will stand behind a wind claim. We use six. What we will not do is tell you the state requires it, because it does not.
Where the code contradicts itself
In 10 southeastern towns — East Lyme, Groton, Ledyard, New London, North Stonington, Old Lyme, Old Saybrook, Stonington, Voluntown, Waterford — the residential appendix and the commercial appendix give different ultimate design wind speeds. The residential table lands between 125 and 129 mph; the commercial table reads 130. A house is designed under the residential table, but the conflict is real. On work in those towns we confirm the governing figure with the building department in writing before ordering material.
Shoreline towns
24 Connecticut municipalities front the water. Salt air attacks fasteners, drip edge, valley metal and flashing before it touches the shingle field, which is why component specifications there differ from inland work.
A note on the 2026 code
Connecticut's next code cycle is expected to take effect in the autumn. When it lands, the appendix is renumbered and some hurricane-region, wind and snow entries change. These pages are built from one table, so they are re-pulled and rebuilt together rather than edited town by town.
Get a straight answer on your roof
Free inspection, a written scope, and a 25-year workmanship warranty.
Common questions
Does Connecticut require ice barrier on every roof?
Yes. Code section R905.1.2 requires it statewide, from the lowest edge of the roof to at least 24 inches inside the exterior wall line, measured along the slope.
How many nails per shingle does Connecticut require?
Four is the code minimum. Shingle manufacturers require six to keep their wind warranty in force. Six is a manufacturer requirement, not a code requirement.
Does the sealed roof deck rule apply to my house?
Only inside the hurricane-prone region, and R905.1.1 carries an exception: it does not apply over lumber sheathing of less than 3 inches nominal width, which is common on pre-1950 Connecticut houses.
Why do two code tables give my town different wind speeds?
In ten southeastern Connecticut towns the residential and commercial appendices disagree. The residential figure governs a house, but the conflict is real and worth confirming with the building department in writing.
Source: Appendix AY, 2022 Connecticut State Building Code, as published by the Connecticut Department of Administrative Services.