Roof snow load by Wisconsin county
Wisconsin's Uniform Dwelling Code sets two roof snow load zones: Zone 1 is 40 psf (pounds per square foot) in the north, and Zone 2 is 30 psf in the south. Counties are assigned in SPS 321.02 and Figure 321.02.[1] If your county sits on the line between them, ask the county or municipal building inspector which zone your lot is in.
Of the 72 counties, 22 sit clearly in Zone 1 and 29 sit clearly in Zone 2. The other 21 fall on the zone line (checked October 2026).[1]
| Zone | Roof snow load | General region | Counties clear of the line |
|---|---|---|---|
| Zone 1 | 40 psf | North | 22 |
| Zone 2 | 30 psf | South | 29 |
| On the line | Ask the inspector | Between the zones | 21 |
Zone 1 counties clear of the line include Ashland, Bayfield, Douglas, Lincoln, Marathon, Oneida, Price, Sawyer and Vilas. Zone 2 counties clear of the line include Dane, Dodge, Kenosha, La Crosse, Milwaukee, Racine, Rock, Waukesha and Walworth.[1]
Counties on the zone line
These counties lie along the boundary: Adams, Brown, Buffalo, Clark, Door, Dunn, Eau Claire, Jackson, Juneau, Oconto, Outagame, Pepin, Pierce, Portage, Shawano, St. Croix, Trempealeau, Waupaca, Waushara, Winnebago and Wood. Jackson County is split by the line.[1]
The code's figure is a scanned map, so a lot near the line needs the inspector's answer. DSPS directs code questions to local code officials and advises homeowners near a boundary to confirm the design value with them.[6]
The full list is on the Wisconsin roof snow load by county table. The Uniform Dwelling Code guide explains who enforces it.
Snow load's effect on gutters and guards
Start with what the number is. The UDC commentary says roof snow loads are applied vertically over the roof area projected onto a horizontal plane, and that sloped-roof reductions may apply.[5] It is a design load for the roof structure.
Ask your local building inspector whether a gutter or guard has a load rating.
A 40 psf roof does not mean a 40 psf gutter. Ask your installer about hanger spacing, fascia condition, gutter pitch and how a guard handles sliding snow before anything goes up.
Pro tip
Ask the installer how the hangers attach and how the guard handles sliding snow, not just what the roof snow load number is.
Sliding snow and ice
Snow load is not only weight sitting in place. The UDC commentary explains that snow can slide onto lower roofs.[3] UW-Extension notes that snow and ice accumulation loads a roof, that denser snow weighs more at the same depth, and that snow sliding onto lower roofs can add significant load.[4]
Those are statements about roofs. Ask an installer how a particular gutter, hanger or guard holds up to a slide.
Still, the mechanism is easy to see at the eave. Snow that releases from a slick roof lands on whatever hangs below it. Metal roofs and the areas below them are worth raising with a pro, along with snow retention devices.
Heavier snow is also a reason to look at the whole edge system. Ask a pro to check:
- Fascia condition and how the hangers attach into solid wood
- Gutter pitch, outlet size and downspout capacity
- How a guard behaves under sliding snow, and whether it can be removed
- Valleys, long roof runs and spots below slick roofing
Snow load is not the same as ice dams
Ice dams are a different problem. They form when melting snow refreezes at the eave, and the cause is usually heat escaping through the roof, not the gutter.
Side by side
Snow load versus ice dams
Snow load
- Weight of snow on the roof
- Snow can slide onto lower roofs
Ice dams
- Melting snow refreezes at the eave
- Cause is usually heat escaping through the roof
A guard does not fix heat loss, insulation or ventilation. Fox Valley Gutters covers the mechanism in depth on its ice dam page, so it is not repeated here.
Clear gutters and downspouts before winter. A blocked downspout can freeze and leave melt water nowhere to go, and that is easier to deal with before the first hard freeze than after.
Gutter work and state licensing in Wisconsin
DSPS does not list a state license for gutters and downspouts. The DSPS A-Z Professions List names 233 credentials and has no entry for this trade (checked October 2026).[2] The building-related credentials it does list include Dwelling Contractor (DC), Dwelling Contractor Qualifier (DCQ), and the electrical, plumbing and HVAC credentials.[2]
That is an absence on a list, not a statute, and it covers gutter work only. Several caveats apply:
- A city can still require its own permit.[2]
- A contractor who pulls a building permit for a one- or two-family dwelling needs the DC and DCQ credentials (SPS 305.31).[2]
- Work that touches plumbing, electrical wiring or HVAC equipment needs those trades' credentials. Heat cable involves wiring, so ask whether it is covered.[2]
Ask the city whether your project needs a permit. Permit pages for cities such as Madison, Green Bay and Waukesha are a good place to start, and the permit data table links to more.
To check any credential a contractor claims, use the DSPS license lookup guide. The city or your building inspector has the final word on what applies at your address.
Gutter pros: where to look in Wisconsin
For gutter installation, guards and ice dam help, start with Fox Valley Gutters, the sister directory for this trade. This site lists no businesses and grades none, so use the directory to compare options and then verify what a contractor tells you.
Bring a short list of questions to the estimate:
- Which snow zone is my lot in, and has the inspector confirmed it?
- How are the hangers spaced and attached, and is the fascia sound?
- How does the guard handle snow sliding off the roof?
- Is this meant to stop ice dams, or only to keep out leaves?
- Do you hold the credentials for any permit, wiring or heat cable involved?
If the roof itself is part of the problem, see roofing in Wisconsin for snow load, permits and licenses.
Quick answers
What is the roof snow load in Wisconsin?
Zone 1 in the north is 40 psf and Zone 2 in the south is 30 psf. Counties on the line need the building inspector's answer.
Does a 40 psf roof mean a 40 psf gutter?
No. The number is a design load for the roof structure, so ask the installer about hangers, fascia, pitch and guards.
Does gutter work need a state license in Wisconsin?
DSPS lists no state license for gutters and downspouts, but a city can still require a permit, and wiring such as heat cable may need its own credentials.
Sources
- Wisconsin Legislature. "Wisconsin Uniform Dwelling Code, SPS 321.02 (roof snow load) and Figure 321.02." https://docs.legis.wisconsin.gov/document/administrativecode/SPS%20321.02. Accessed October 17, 2026.
- Wisconsin Department of Safety and Professional Services. "DSPS A-Z Professions List." https://dsps.wi.gov/a-z-professions-list/. Accessed October 17, 2026.
- Wisconsin Department of Safety and Professional Services. "Chapter SPS 321 Subchapter I — Scope 321.02 Load Paths." https://dsps.wi.gov/MediaFileLocation/bkmk4r0t/sps-321-commentary.pdf. Accessed October 17, 2026.
- University of Wisconsin–Extension, Lincoln County. "Snow Loads on Farm Buildings." https://lincoln.extension.wisc.edu/2018/04/16/snow-loads-on-farm-buildings/. Accessed October 17, 2026.
- Wisconsin Department of Safety and Professional Services. "Snow Load and Roof Design Commentary." https://dsps.wi.gov/MediaFileLocation/bkmk4r0t/sps-321-commentary.pdf. Accessed October 17, 2026.
- Wisconsin Department of Safety and Professional Services. "Uniform Dwelling Code Administration and Enforcement." https://dsps.wi.gov/Pages/Programs/UDC/Default.aspx. Accessed October 17, 2026.