Fifteen pounds per square foot of ground snow at Wichita is the load that starts every truss calculation in the region, and on an ordinary sloped house roof it comes down to roughly ten psf once slope and heat are factored in. That number, not a bigger one from a newer map, is what belongs on the permit application right now. Before you sign off on a re-roof or a new build, ask your county or city building department which code edition they have adopted, since Kansas sets no single statewide rule and the answer changes what your truss drawings and your ice barrier requirement actually say.
What is the ground snow load in Kansas?
The design ground snow load mapped at Wichita is 15 psf under ASCE 7-16, the edition that IRC/IBC 2021 makes applicable in most states. That figure is what a permit application cites, what a plan reviewer checks against, and what a truss manufacturer builds its drawings around before a single rafter goes up.
Ground load versus roof load
Fifteen psf is not what actually sits on the shingles. It is the load the code assumes accumulates on open, level ground before wind scours it, heat from the house melts part of it, and the roof’s own slope sheds the rest. Run those factors through the code’s conversion and an ordinary heated house with a sloped roof ends up carrying roughly 10 psf of actual roof snow load, not 15. That gap between ground and roof is the single most common point of confusion on this subject, and it is worth remembering every time a different number shows up somewhere else.
A newer edition, ASCE 7-22, maps the same point at 23 psf. That is not three times more snow falling on Wichita. It is a strength-level figure meant to be used with a 1.0 load factor, where the 7-16 figure is nominal and paired with a 1.6 factor. The two numbers answer different engineering questions, and a jump from one to the other says nothing about whether an existing roof is now undersized.
Wichita is the reference point behind both figures. Elevation and local weather patterns shift the real number across the state, so a roof in the Flint Hills or in a river valley in the northeast is not designed to the same load as one in south-central Kansas. Whatever the true figure at a given address, the design value is a life-safety number. It belongs on a plan review, and confirming it is a job for a licensed engineer or the local building department, not for a general guide.
How much snow can a roof hold in Kansas?
There is no single depth of snow a roof in Kansas can or cannot hold. It depends on the roof’s design load, its slope, and what the snow itself has turned into by the time it is sitting up there.
Why drift matters more than the forecast
Start from the ground figure. At Wichita, the design ground snow load of 15 psf converts to roughly 10 psf on an ordinary sloped roof. That is the number for a plain, unobstructed roof plane. It is not the number against a parapet, below a dormer, in a valley between two roof sections, or on a lower roof next to a taller one. Wind moves snow off the high, exposed parts of a roof and drops it in the low, sheltered ones, and drifted snow load can run well above the open-field figure the code starts from. Most roof failures under snow happen at these drift points, not across the plain field of the roof.
The other variable is what the snow itself weighs. Fresh, light snow runs roughly 5 to 7 pounds per square foot for every foot of depth. Once it settles, gets rained on, or partially melts and refreezes, that same depth can weigh two to three times as much. A layer of ice on top of compacted snow adds more again. That is why a foot of snow sitting on a roof in January is a different load than a foot that fell in March and has had a week of freeze-thaw working on it. Depth alone tells you almost nothing without knowing what has happened to the snow since it landed.
Watch for signs that a roof is carrying more than it should:
- Interior doors that suddenly stick or won’t latch
- New cracks in ceiling drywall, especially near the center of a span
- A ridge line that looks like it is bowing or sagging from the ground
- Popping or cracking sounds from the attic under load
If any of those show up, clear snow from the ground with a roof rake rather than climbing onto a loaded roof, and call a licensed engineer or the local building department if the roof shows signs of structural distress. Readers dealing with far heavier design loads, like the ground snow figures used in the Prince Edward Island’s roof snow load and wind rules guide, face drift on a different scale entirely, but the mechanism doing the damage is the same one at work on a Kansas roof.
What wind speed must a roof withstand in Kansas?
The basic design wind speed mapped at Wichita is 110 mph under ASCE 7-16, for Risk Category II buildings, which covers ordinary houses. That number is a 3-second gust measured at 33 feet in open, Exposure C terrain, not a sustained wind and not what a weather forecast means when it reports a wind speed. Comparing it directly to a hurricane’s headline number, which is usually a sustained speed, makes the code figure look weaker than it is. The two are measuring different things entirely.
What the gust speed governs
ASCE 7-22 maps the same point at the same 110 mph, so the two editions agree here and there is no shift to track between them at Wichita. That figure drives several things at once: the wind rating a shingle needs, the nailing pattern a roofer follows, how the sheathing gets fastened to the rafters, and the uplift connections tying the roof structure down to the walls. Edges, rakes and ridge lines are where uplift concentrates in a wind event, which is why those areas get tighter fastening schedules and extra clips or straps on a properly built roof, and why they are usually the first parts of a roof to show damage after a storm.
Wichita is the reference city behind the 110 mph figure, and wind speed on the ASCE map moves with location the same way snow load does, so a different part of the state can carry a different design value. Like snow load, this is a life-safety figure that belongs on a plan review. Confirm the exact value and any local wind provisions with the building department that issues the permit, not from a statewide assumption, since Kansas has no single residential code setting one answer for the whole state.
Does Kansas require an ice barrier under the shingles?
An ice barrier is a self-adhering waterproof membrane installed under the shingles, run up from the eave edge past the interior line of the exterior wall. Its job is not to stop snow. It is to stop meltwater, backed up behind an ice dam, from finding a seam and reaching the roof deck.
What actually causes an ice dam
Ice dams form when heat escaping from a heated attic melts the underside of the snowpack. That meltwater runs down the roof until it reaches the cold overhang past the exterior wall, where there is no warmth coming through from below, and refreezes there. The ice builds into a dam, and water backs up behind it under the shingles. NOAA’s 1991-2020 climate normals put the coldest month’s average daily minimum at Wichita at 22.5°F, cold enough for meltwater to refreeze reliably at the eave once it forms, and the region’s design snow loads mean there is usually snow on the roof to melt in the first place. Both conditions have to be present for a dam to form, and around Wichita they usually are during winter.
A membrane at the eave protects the deck from the water an ice dam produces. It does not stop the dam from forming. Only air sealing the attic floor and adding enough insulation stop the heat loss that melts the snow in the first place. A roof with a membrane sitting over a leaky, under-insulated attic still grows ice dams every winter. It just keeps the water out of the ceiling while it does.
Kansas has no statewide residential building code. No state agency administers one, and adoption of any code at all, including whether it contains an ice barrier provision, is decided entirely at the city or county level. The state only enforces a construction code on state-owned buildings and applies its fire prevention code uniformly across Kansas. That means whether an ice barrier is required on your project depends on which code, if any, your specific city or county has adopted. Ask the permitting office directly rather than assuming a national default, since a jurisdiction two counties over can have adopted something entirely different, or nothing at all. Kentucky readers working through a similar question can see how a state with its own statewide code answers it in Kentucky’s roof snow load and wind rules, which makes a useful contrast to how Kansas leaves the decision local.
What roofing material suits Kansas best?
The combination that matters here is Wichita’s 15 psf ground snow load, its 110 mph basic design wind speed, and a climate split across IECC zone 4A in 88 of the state’s 105 counties and zone 5A in the remaining 17. That mix rules out a single best material and points instead to what each option changes under those specific loads.
Before comparing materials, general roofing basics like decking, flashing and ventilation are covered in our Roofing guide, which this page assumes you have already worked through.
Comparing the main categories under Kansas loads
| Material | Wind performance | Snow behavior | Added dead weight |
|---|---|---|---|
| Architectural asphalt shingles | Wind rating printed on the wrapper, but depends entirely on correct nailing to that rating | Holds snow in place rather than shedding it | Low |
| Standing-seam metal | Performs well when panels and clips are installed to the manufacturer’s wind zone | Sheds snow and ice off the slope in sheets | Low |
| Slate or concrete tile | Heavy tiles resist uplift on their own weight, but fastening still matters at edges | Holds snow similarly to shingles | High, added directly to the snow load the structure already carries |
Standing-seam metal’s snow-shedding is a design decision as much as a material property. A slope that sheds cleanly can dump a slab of snow and ice onto a doorway, a walkway or a driveway below, so where that edge discharges has to be planned, usually with a snow guard system or a roof line aimed away from foot traffic.
Slate and concrete tile carry their own weight on top of whatever snow load the roof already has to support. That added dead weight has to be accounted for in the structural design from the start, not added after the fact once the tile has already gone on the roof.
Fastening and underlayment matter more than the material itself wherever wind is the governing load. A shingle rated for a high wind speed, nailed with the wrong pattern or spacing, performs to the standard of the nailing, not the rating on the package. The same is true of clip spacing on a standing-seam roof and of tile fastening at hips and ridges, where uplift concentrates most.
Wichita’s figures are the reference point for all three comparisons above. A roof in a windier corridor or under a heavier local snow load carries different numbers, so confirm both design values with the local building department before choosing between these categories on a specific project.