Your new driveway met salt in its first winter and started flaking

Decide this before the pour, not after the first snowfall: nothing salty touches the new concrete, and you tell everyone who plows, shovels or parks on it. That one decision protects more of your money than any product on a store shelf. Ask the contractor to put the first-winter rules in the written scope, and read them back before you sign.

Most owners think salt damage needs a shaker in your hand. It does not. The trade group NRMCA says cars carry road salt onto driveways and garage slabs, and that magnesium-based road treatments ride in on tires too.

So the slab that takes a heavy dose can be the garage floor, where slush melts off a parked car and sits. The apron at the street gets the same treatment from every vehicle that crosses it. Look at where your tires drip, and expect that strip to wear first.

You can cut the load. When the weather allows, hose the dried salt and slush off the driveway and the garage floor, and clear puddles that sit on the surface. NRMCA warns that poor drainage, which lets salty water pool, raises the severity of the exposure and can cause scaling.

New concrete holds a lot of water. Until it dries and gains strength, that water can freeze inside the surface and flake it off in thin sheets. The flaking is called scaling, and it often starts as small patches that later merge.

Salt makes the flaking worse. NRMCA warns that heavy de-icer use raises the chance of scaling. You do not need the chemistry. You need to know that the first winter is when the surface is weakest and the exposure is harshest.

Ask your contractor one plain question: what is the plan for the first winter, and where is it written? If the answer is a shrug, the repair is being set up to fail the way the old slab did.

Two numbers get mixed up, and the mix-up leads to bad advice. They measure different things, so keep them apart.

• Protection period. ACI 306R-16 gives 2 days for normal-set concrete that carries no load and is not exposed, 3 days when it is exposed, and 6 days when it carries partial load and is exposed. This is the time to keep cold weather off the slab.
• Curing. NRMCA says curing should continue for a sufficient period, typically 3 to 7 days. This is the time to keep the slab from drying out too fast.

Cold weather, by that standard, means the air temperature has fallen or is expected to fall to 40F or below during the protection period. It is not the temperature at the moment of the pour. Ask which day count the contractor uses and what the plan is for a cold night inside it.

The same standard cautions against water curing in cold weather, because it can leave the surface saturated when the protection comes off. If your pour lands in a cold stretch, ask how the slab will be covered and when the covers come off.

NRMCA states a plain rule: avoid de-icing chemicals in the first winter, and use moderate amounts after that. For new concrete it says to use clean sand for traction instead. Sand does not melt ice, but it keeps you on your feet and costs the slab nothing.

Tell your household and anyone who clears your snow. A bag of rock salt from a helpful neighbor can undo a good pour. A short note on the garage door does the job.

NRMCA also names the products to leave out entirely. Ammonium sulfate, ammonium nitrate and magnesium-based salts are harsh on concrete and should stay off. Read the bag before you buy anything labeled as a driveway melter. If you are unsure, skip it and shovel.

After that first winter, NRMCA says to use de-icing chemicals in moderate amounts. New York State's Department of Environmental Conservation says 12 ounces of rock salt is enough to melt snow and ice on a 20 foot driveway, and that rock salt will not work below 15F.

Shovel first. DEC points out that clearing what you can reduces the salt you need. That is better for the slab and for the water that runs off your property. Pick up the shovel before the spreader.

NRMCA recommends a breathable silane or siloxane sealer made for concrete slabs, put down after the concrete is reasonably dry. It names late summer, with a few dry days before application, as the ideal time.

A sealer is something to discuss, not a product to accept without reading. Ask the contractor whether it belongs in the scope, which product, and when it goes on. Ask whether it changes the date you can first use de-icer. A sealer does not replace air-entrained concrete, and it does not excuse a pour in the wrong month.

Syracuse is cold early. NOAA normals show it averaging 13.9 nights at or below 40F in October and 24.2 in November. The year as a whole records 186.3 days with a minimum at or below 40F, which is the cold-weather trigger in the ACI standard.

A pour in late fall can see three cold nights inside its protection period. A pour in summer gets weeks of strength before the first frost. If you have a choice of dates, ask the contractor to explain the choice in terms of those nights. If the slab has to go in late, ask what covers and heat will be used.

The mix matters as much as the month. NRMCA says concrete that will be wet, frozen and salted should be air-entrained, and NRMCA recommends 6 percent air for slabs made with three-quarter or one inch stone. The Residential Code of New York State asks for 5 to 7 percent air in the severe case. Put the air content in writing.

Use this as a short list when you read a quote. Every line should be answered in writing, not on a phone call.

1. The mix: air-entrained, with the air content and strength named.
2. The pour date and a fallback date if a cold night is forecast.
3. How the slab is covered, and for how many days.
4. What you must not put on the slab, and for how long.
5. Whether a sealer is included, which product, and when it goes on.
6. Who removes the covers and walks the slab with you afterward.

Strength figures differ by source, from 3,500 psi in the New York residential code to 4,000 psi from NRMCA. You do not have to settle that argument. Ask which figure the quote uses and why.

Thin flaking on a slab that is otherwise sound is mostly cosmetic. NRMCA says minor scaling may not need repair, and that a slab with heavy, spreading scaling may not be repairable at all. A repair surface is only as strong as the concrete underneath it.

So ask for an honest look before anyone offers a resurfacing coat. Ask whether the old surface will be removed down to sound concrete, and whether the new material will match in color. Repair material will not match the original, and a contractor who says otherwise is selling.

When you are ready, send us the slab and what it is doing. We help you work out what to ask for, then introduce you to an independent contractor in the Syracuse area. You decide what comes next, and your contract is with the contractor.