Green Bay averages about 55 inches of snow a year, and the average January night drops to around 11°F. Your driveway gets plowed, shoveled, salted, driven on with slush-packed wheel wells, and buried under the pile at the end of the drive until April.
Concrete doesn't need babying through all that. It needs a few habits that keep water and salt from doing their slow damage. For the science of why freezing water breaks concrete apart, see freeze-thaw concrete damage. This page is the routine.
A Green Bay Winter, by the Numbers
| Month | Normal high | Normal low | Normal snow | What it means for your concrete |
|---|---|---|---|---|
| November | 43.5°F | 28.9°F | 3.1" | Nights average below freezing. Outdoor caulking and sealing are mostly done. |
| December | 31.1°F | 18.0°F | 13.1" | Ground freezes in. Wisconsin's frozen-road period starts around December 22 on average. |
| January | 25.5°F | 11.1°F | 14.3" | The average night is colder than rock salt works. |
| February | 29.0°F | 13.2°F | 12.0" | Same cold, plus sunny afternoons that melt roof snow and refreeze it at night. |
| March | 40.4°F | 23.9°F | 8.1" | Above freezing by day, below at night, with salt already soaked in. |
1991–2020 normals for Green Bay, from the Wisconsin State Climatology Office.
Rock salt is the wrong tool for a lot of January nights. And March can be harder on concrete than January, because it crosses freezing over and over with brine already in the surface.
Before the First Snow: The Pre-Winter Checklist
Green Bay's normal low dips below 40°F in October, and most caulk and sealer labels list 40°F as their minimum. The outdoor jobs here have a deadline.
| Job | Get it done by | Why it matters |
|---|---|---|
| Caulk open joints and the gap along the house | Early October, dry day, 40°F+ | Open joints are a straight path for meltwater under the slab. See best concrete crack caulk. |
| Seal with a penetrating silane or siloxane sealer | Late August to early October, inside the label's range | Cuts how much brine soaks in. See why seal concrete. |
| Lift any slab that has sunk | Before the ground freezes | A low spot becomes an ice patch and funnels melt underneath all winter. See concrete lifting in winter. |
| Extend downspouts and aim the sump line away from concrete | Before the first snow | Thaws send roof melt across walks to refreeze. See how to extend downspouts. |
| Set plow stakes | Before the ground freezes, while they'll push in | Nobody can see a concrete edge under a foot of snow. |
| Buy ice melt and a bag of sand; put garage mats down | Before the first storm | You'll read labels at home instead of grabbing what's left at the store. |
Ice Melt Compared
Read the ingredient list, not the front of the bag. "Safe for concrete" and "pet friendly" are marketing claims.
These ratings are pavement temperatures, not air temperatures. Wisconsin's DOT notes that sun can push pavement surfaces into the 50s on days when the air is in the 20s and 30s. A shaded north-side walk can run colder than your thermometer.
| Product | Works down to (pavement) | Effect on concrete | Pets | Lawn and plants | Our take |
|---|---|---|---|---|---|
| Rock salt (sodium chloride) | About 15°F | No chemical attack like the next two, but brine makes freeze-thaw scaling worse | A few licks are usually minor; eating a lot is dangerous | Rough on lawns; sodium builds up and damages soil structure | Fine on mature, sound concrete, lightly, above 15°F |
| Calcium chloride | About -20°F | Can form calcium oxychloride in the cement paste, which expands and cracks concrete even above freezing, especially in joints | Among the harshest irritants on paws and mouths | Somewhat less harmful than rock salt | Deep-cold days only. Spot-treat and rinse it out of joints. |
| Magnesium chloride | About -10°F (ratings vary) | Same oxychloride risk, and magnesium can weaken the paste. Testing ties it to more scaling than rock salt. | Mostly stomach upset if eaten | Less harmful than rock salt, not harmless | Often sold as the gentler choice. On concrete, it isn't. |
| Potassium chloride | About 25°F | Less studied; it's still a chloride, so treat it like one | A strong irritant if eaten | Easier on plants than rock salt | Does almost nothing in a Green Bay January |
| CMA (calcium magnesium acetate) | About 20°F | Easy on metal, but engineering sources report its magnesium can scale concrete more than chlorides. Many blends add chlorides. | Calcium salts are among the more irritating if eaten | Little effect | Pricey, mild days only. Good near prized plantings. |
| Sand or grit | Doesn't melt | None | The safest choice | Little effect; sweep it up in spring | The answer for new concrete and for days too cold for your melt |
Never use ammonium nitrate or ammonium sulfate on concrete. Both are fertilizer ingredients that attack concrete, so check the label and sweep spilled lawn fertilizer off the driveway too. Many "pet friendly" melts are urea-based, which works only to about 25°F.
For what years of salt do to a slab's surface, see why concrete flakes.
How Much Is Enough
Less than you think. Wisconsin's Salt Wise campaign uses a simple yardstick: one coffee mug of salt covers about a 20-foot driveway or roughly 10 sidewalk squares. Scatter it with space between the grains. A white crust is wasted salt, and it doesn't make the walk any safer.
A worked example for a typical house:
- Front walk and stoop: 4 feet wide, 30 feet long, in 5-foot squares. That's 6 squares, a bit over half a mug.
- 40-foot driveway: about 2 mugs for the whole thing. Most days you only need the path to the door and the spot where tires stop at the garage. Not half a bag.
- Below 15°F: skip the rock salt. Sand for grip, plus a light handful of calcium chloride on the one spot that must be clear, like the stoop.
Melt only has to break the ice's grip so the shovel can finish the job. Shovel the slush off once it lets go.
Get the Snow Off Before It Turns to Ice
Fresh snow comes off easily. Snow that's been driven on, walked on, or rained on packs into ice bonded to the surface, and then you need melt, time, and more work.
- Shovel during long storms, not just after.
- Clear the apron and tire paths before you drive out. Tires pack snow into ice faster than anything.
- Never chip ice off concrete with a steel chopper or a spade. It takes the surface with it.
Plastic vs. steel blades: A plastic blade is gentle, and right for anything sealed, stamped, or coated. A steel-edged blade cuts hard-pack but scrapes the surface and chips slab edges and caulk beads, so keep it flat and don't stab at joints. A rubber-edged pusher handles slush and the garage floor. On a snowblower, set the skid shoes so the scraper bar skims instead of digs.
If your shovel or blower catches the same edge every time, one slab has likely sunk below its neighbor. That's a lifting problem, not a technique problem.
Plow Stakes and Plow Contractors
A driveway's edge is its weakest part, and the plow can't see it under snow. A blade that drops off the edge chips the slab. One that catches a raised joint at the apron can snap a corner off.
Stake the edges in October or early November, before the ground freezes: each apron corner, both sides of the drive, and anything that sticks up, like a raised slab edge.
If you hire a plow contractor, tell them before the first storm:
- Where the concrete ends, including any raised edge or sunken slab.
- Where the snow goes: on the lawn, downhill from the house. Not on the walk, against the garage, or on the AC pad.
- What melt they use. No ammonium products ever, and nothing at all on concrete poured this year.
- Go easy at the apron and garage door, where lips catch blades. Ask whether their plow can run a rubber or urethane cutting edge.
Where the Snow Goes
A snow pile's weight isn't the problem. Its meltwater is. A pile on concrete melts across it for weeks, soaks the joints, and refreezes every night.
| Spot | OK? | Why |
|---|---|---|
| Lawn, downhill from slabs and the house | Yes | Melt soaks in away from concrete |
| A walk, patio, or the apron | No | Weeks of meltwater over and into the slab |
| Against the foundation or garage wall | No | Melt soaks the loose backfill along the house, where a lot of sinking slabs start |
| The AC pad or downspout outlets | No | Blocks drainage and buries equipment |
| The street or alley | No, in Green Bay | The city prohibits moving snow from private property onto streets and alleys |
Green Bay also requires sidewalks cleared within 24 hours after snow stops falling. Other municipalities set their own rules.
Downspouts and Splash-Zone Ice
On sunny February afternoons, roof snow melts and runs out the downspouts onto frozen ground. It crosses the walk, refreezes overnight, and becomes the ice patch you salt every morning.
- Keep outlets clear. An extension frozen into a snow pile backs water up, and the overflow spills next to the foundation.
- Route melt to the lawn, not across a walk. A hinged or flexible extension can point a different way in winter. Buried lines that don't drain empty freeze solid (more here).
- Sand the splash zone instead of salting it twice a day.
The Garage: Where Salt Does the Most Damage
Every time you pull in, salty slush falls off the wheel wells and lands in the same two strips where your tires park. In an unheated garage, that puddle thaws and refreezes for months, soaking a little deeper each time.
- Squeegee it out the door after each storm, before it soaks in.
- Use containment mats with a raised lip under each vehicle, and empty them on mild days.
- Keep the floor drain clear, if you have one.
- Rinse on an above-freezing day and squeegee the floor dry. Skip the pressure washer in a cold garage.
Our garage floor cleaning guide covers removing salt residue, and a garage floor coating keeps brine out of the concrete altogether.
The First-Winter Rule for New Concrete
Concrete poured this year gets no deicer of any kind this winter. Concrete industry guidance says to keep deicers off new concrete for its first year. Use sand and shovel more often.
- Fall pours usually can't be sealed before winter. Sealer labels want the concrete cured first, often 28 days, and by then nights are dropping below the 40°F most labels require. Seal next late summer.
- Tell your plow contractor it's new: no salt.
- Use a plastic shovel, and put mats down if the garage floor is new.
City salt spray will still reach the sidewalk by the street, so rinse it on a mild day. More in why new concrete cracks.
The Mid-Winter Thaw Checklist
When the forecast shows a day or two above freezing, use it.
- [ ] Push slush and standing water off before it refreezes tonight.
- [ ] Open frozen downspout outlets and aim extensions at the lawn.
- [ ] Rinse salt off the apron, walks, and garage floor at midday, toward the lawn rather than the street drain, and only if it'll dry or get squeegeed before dark.
- [ ] Pull snow piles back from the house and slab edges so melt has a path away.
- [ ] Sweep up leftover salt and sand, and check the sump outlet for ice.
- [ ] Photograph any ice patch that forms in the same spot every time. That's a low slab, and the photo helps with a spring quote.
- [ ] Note any slab that rose, but don't judge it yet. See frost heave vs. settling.
Don't caulk, seal, or pressure wash on a 45°F January afternoon. The joints are cold and wet, and the frost hasn't left them.
What Winter Care Can't Fix
You don't need us to shovel smarter, buy the right melt, or point a downspout at the lawn. But good habits won't fix:
- A sunken slab. It holds a puddle that freezes every night and sends melt under the slab next to it. That's a lifting job.
- Flaking that has already happened. Better habits slow it down. They don't bring the surface back.
- Joints left open going into winter. By January it's too cold to caulk them.
Spot one? We don't lift on frozen ground, but we quote from photos all year and can schedule you for after the thaw.