A permit application for a house near Columbus lists a ground snow load of 20 psf, and after the usual roof conversion factors that number works out to roughly 14 psf sitting on an ordinary sloped, heated roof, not on bare ground. That converted figure, not the ground one, is what a truss drawing gets stamped to. Check with your own county building department before assuming the Columbus number applies to your address, because snow load in Ohio shifts with elevation, lake effect and local drift patterns.
What is the ground snow load in Ohio?
The design ground snow load at Columbus is 20 psf under ASCE 7-16, the edition that IRC/IBC 2021 makes applicable in most states and the one behind the current Ohio permit process. That figure is a load measured on open, level ground, not on a rafter. Wind exposure, roof slope and how much heat escapes into the attic all change that number before it becomes a design load on an actual roof. For an ordinary heated house with a sloped roof, the code’s conversion factors bring the Columbus ground figure down to roughly 14 psf of roof snow load, the figure a truss engineer actually designs to.
This number is not a curiosity. It is what goes on the permit application, what a plan reviewer checks against the submitted truss package, and what the truss manufacturer stamps its drawings to before lumber gets cut. A house built without meeting it is a house that has not been reviewed against the load Ohio’s building officials expect it to carry. The residential code Ohio enforces, based on the 2018 IRC, is where the ASCE 7 snow figures get folded into an actual permit requirement rather than staying a number on a national map.
A newer edition, ASCE 7-22, maps the same point in Columbus at 31 psf. That is not three times the snow. ASCE 7-22 states its figures on a strength-level basis, meant to be used with a 1.0 load factor, while ASCE 7-16’s 20 psf is a nominal value used with a 1.6 load factor. The two numbers describe different math, not a worsening winter, and jurisdictions beginning to adopt 7-22 are not saying Ohio’s existing roofs are suddenly undersized.
The 20 psf figure belongs to Columbus specifically. Snow load across Ohio shifts with local terrain, and the lake-effect snowbelt counties near Lake Erie see conditions the Columbus reference point does not capture. A homeowner outside central Ohio should ask their county building department for the ground snow load value that applies at their address rather than assume the capital city’s number travels with them.
How much snow can a roof hold in Ohio?
There is no single number for how much snow a roof can hold, because the answer depends on the roof’s shape, its condition, and what the snow itself has turned into. The 14 psf roof snow load derived from Columbus’s ASCE 7-16 ground figure describes an ordinary, evenly loaded sloped roof under uniform snow cover. Real winters do not load roofs evenly.
Where drift changes the math
Wind picks up snow from a long, open roof slope and drops it against anything that interrupts the flow: a parapet, a taller adjoining wing, the wall behind a dormer, or the valley where two roof planes meet. In those spots, the local load can run well above the uniform 14 psf figure the code assigns to the rest of the roof, because drift piles snow several times deeper than what fell evenly elsewhere. That is why roof failures cluster at valleys, behind chimneys and below abrupt roof-height changes rather than at the ridge of a plain gable.
Why depth alone tells you little
A foot of fresh, dry snow in January is a very different load than a foot of snow in March. Freshly fallen, light snow runs roughly 5 to 7 pounds per square foot for each foot of depth. Once that snow settles, gets rained on, or partially melts and refreezes, the same depth can weigh two to three times as much. A layer of ice on top of compacted snow adds more weight still, in a much thinner layer than the snow it sits on. That is the reasoning to use instead of a rule of thumb about inches. Two feet of light powder and eight inches of saturated, refrozen slush can carry a similar load, and only the second one is likely to be a real problem.
Signs to watch, and what to do
- Interior doors that suddenly stick or won’t latch
- New cracks or a popping sound in ceiling drywall
- A visibly sagging ridge line or a roof plane that looks wavy from the ground
- Sagging or creaking that gets worse after rain falls on top of existing snow
Any of those is a reason to act, and the safe response is to remove snow from the ground with a roof rake rather than climb onto a loaded roof, which adds a person’s weight to a structure that may already be near its limit. If the roof shows real distress, a licensed engineer or the local building department is the right call, not a guess based on how many inches are up there.
What wind speed must a roof withstand in Ohio?
The basic design wind speed at Columbus is 108 mph under ASCE 7-16, and that number needs its fine print read before it means anything. It is a 3-second gust measured at 33 feet above open, level ground, Exposure C, for Risk Category II, the category that covers ordinary houses. It is not a sustained wind speed, and it is not comparable to the wind speed a weather forecast quotes for a storm system moving through; it is one engineered against a specific, short-duration peak measured a defined way.
ASCE 7-22 maps the same point in Columbus at essentially the same figure, 108 mph, so unlike the snow load, the wind number does not shift meaningfully between the two editions here.
Columbus’s inland location means the figure used for this page carries no wind-borne debris designation, the flag that in hurricane-prone coastal counties forces impact-rated glazing or approved shutters on new construction. States with active hurricane exposure, like the coastal counties covered in the Georgia’s roof snow load and wind rules guide, carry that added glazing requirement and the added cost that comes with it. Ohio’s design wind figure, by contrast, is mainly a structural question rather than a glazing one.
What the 108 mph figure governs on an actual roof is the shingle’s wind rating, the nailing pattern used to install it, how the sheathing is fastened to the rafters or trusses, and the metal connectors, straps or clips that tie the roof structure down to the walls. Edges, rakes and ridges fail first in a wind event because that is where uplift pressure concentrates, which is why code-compliant installation pays particular attention to fastening in those zones rather than treating the whole roof field the same way.
Wind figures vary sharply with geography inside a single state’s borders, more so than snow load does in a place like Ohio. A reader just across the state line, in a market covered by the Pennsylvania’s roof snow load and wind rules guide, is working from an entirely different reference point, so figures should never be carried from one state page to another.
Does Ohio require an ice barrier under the shingles?
An ice barrier is a self-adhering waterproof membrane installed under the shingles, run from the edge of the eave up the roof slope far enough to pass the interior line of the exterior wall. Its job is not to stop snow from sitting on the roof. It is there to stop water from getting under the shingles when an ice dam backs meltwater up against the normal downhill flow, at the one part of the roof where shingles alone are not enough to keep that backed-up water out.
Why ice dams form here
Columbus’s coldest-month average low sits at 22.0°F, based on NOAA’s 1991-2020 climate normals, cold enough for a sustained snowpack to sit on a roof for days at a stretch. An ice dam does not need extreme cold to form. It needs a roof surface warm enough at the field to melt the snow directly above living space, and cold enough at the unheated eave overhang to refreeze that meltwater into a ridge of ice. The heat driving that melt comes from the attic below, whether from an under-insulated ceiling, an unsealed attic hatch, or a bathroom fan vented straight into the attic instead of outdoors. The membrane under the shingles is a backstop against water that already got that far. It does not stop the dam from forming in the first place. Only air sealing the attic floor and adding insulation address the actual cause, and a reader who installs the membrane alone has protected the deck without doing anything about the ice dam itself.
What Ohio’s code says
The code that governs this in Ohio is the Residential Code of Ohio for One-, Two-, and Three-Family Dwellings, 2019 edition, based on the 2018 International Residential Code, administered statewide by the Ohio Board of Building Standards. It is a uniform code: no city or county in Ohio may weaken it, though the permit itself is still issued and inspected locally. The 2019 Ohio code carries forward the base 2018 IRC’s eave protection requirement in areas with a history of ice forming along the eaves, a category the Columbus climate normals above put Ohio squarely inside. The specific extent of coverage required, and how it is verified on your project, is a question for your local building department at the time of permit, not something this page can settle for every roof in the state.
What roofing material suits Ohio best?
The honest answer depends on which of Columbus’s numbers matters most for a given roof: the 14 psf converted snow load, the 108 mph design wind speed, or the added dead weight a heavier covering puts on top of both. Ohio also splits across two IECC climate zones, with 64 of its 88 counties in zone 5A and 24 in zone 4A, which affects insulation choices more than it affects the roofing material itself, but it is worth knowing the state is not climatically uniform even without snow and wind in the picture.
Architectural asphalt shingles are rated for a wind speed by the manufacturer and hold that rating only if installed with the nailing pattern the rating assumes. The shingle’s printed rating and the installer’s actual nailing pattern are two different things, and a shingle rated for high wind, nailed to a lower standard, performs to the lower standard, not the one on the wrapper.
Standing-seam metal sheds snow far more readily than a shingle roof, which is an advantage on the roof itself and a hazard everywhere the snow lands. A metal roof over an entry, a walkway or a driveway needs that slide path accounted for at the design stage, whether with snow guards or by directing the roof plane away from where people walk, rather than discovered the first time a sheet of snow lets go over a front door.
Slate and concrete tile carry loads asphalt and metal do not. Both add substantial dead weight of their own, on top of whatever snow load the roof structure is already designed to carry, so a re-roof from a lighter material to either one is a structural question, not just a finish choice, and it is the kind of change a building department or engineer should sign off on before it happens.
| Material | Wind performance | Snow behavior | Added dead load |
|---|---|---|---|
| Architectural asphalt shingles | Rated by manufacturer, only as good as the nailing pattern used | Holds snow on the surface, sheds slowly | Low |
| Standing-seam metal | Strong when properly fastened at seams and edges | Sheds snow quickly, often in a single slide | Low to moderate |
| Slate or concrete tile | Heavy units resist uplift but fastening at edges still governs | Holds snow, sheds slowly | High, adds to the structure’s own snow load |
None of this replaces a look at the whole roofing system before choosing a covering. Whatever the material, the deck, the underlayment and the flashing details covered under general roofing practice matter as much to how the roof performs in Ohio’s winters as the surface material itself.