Cool weather slows concrete down. That is good for strength in the long run, but it means waiting times in Anchorage are often longer than the numbers you read for warmer places.
How long does concrete take to cure?
Concrete reaches most of its design strength in about 28 days at mild temperatures. It is hard to the touch within a day. When days are in the 50s and nights in the 40s, as in an Anchorage May or September, strength builds more slowly and every waiting time stretches. Keeping the slab damp or covered for the first week helps it get there.
How long before I can walk on new concrete?
You can walk on new concrete after about 24 to 48 hours in summer. Give it an extra day in cool weather. Keep dogs, bikes and anything with a narrow wheel off for a few days, since they mark the surface.
How long before I can drive on new concrete?
Wait at least 7 days before you drive on new concrete with a car, and closer to 10 if the weather has been cool. Keep heavy pickups, motorhomes, trailers and delivery trucks off for about a month. Do not turn the steering wheel while standing still for the first few weeks.
How long does it take to pour a driveway?
To pour a driveway takes one day. The whole job is usually three to five working days: tear-out and excavation, gravel and compaction, forms and steel, then the pour and finishing. A deep dig to get rid of frost-prone soil adds a day or more, and rain can shift the pour date.
Can concrete be poured in the rain?
Not in steady rain. Concrete can be poured in the rain only if it is light and the crew can cover the slab, and even then the finish is at risk. August and September are the wettest months here, so late-season pours are scheduled with a backup day. A base that is soaked and soft has to dry or be reworked first.
Is it too hot to pour concrete in summer?
It is almost never too hot to pour concrete in Anchorage. Summer highs are usually in the 60s and low 70s, which is close to ideal. The summer risk here is different: long hours of sun, low humidity and wind dry the surface quickly. We dampen the base, finish promptly and start curing straight away.
Can concrete be poured in cold or freezing weather?
It can, with care and added cost. Concrete must not freeze before it has gained early strength, and it must never be placed on frozen ground. Cold-weather pours use heated water in the mix, insulated blankets and sometimes a heated tent. For driveways and patios we normally advise waiting for the season. Building foundations are the work most often done with winter protection.
What is the best time of year to pour concrete in Anchorage?
The best time of year is late May through August. The ground has thawed and dried out after breakup, nights stay above freezing, and the slab has time to cure and be sealed before the first frost. Early September can work. Later than that, the slab goes into winter young and unsealed, which raises the risk of surface flaking.
Can I use salt or deicer on new concrete?
No deicer in the first winter. Salt and other deicers keep the surface wet and add freeze cycles, and young concrete cannot take it. Use sand or fine gravel for grip, which is what most Anchorage owners do anyway. After the first year, use deicer sparingly and avoid products with ammonium nitrate or ammonium sulfate, which attack concrete. Remember that cars carry road deicer into the garage.
What should I do in the first week?
- Keep the slab damp or leave the curing cover in place as we instruct.
- Keep sprinklers, leaves and tarps from leaving marks on the surface.
- Stay off with vehicles for the full waiting time.
- If frost is forecast, cover the slab with insulating blankets overnight.
- Call us if you see anything that worries you.
The only real price is one written after we have seen the site. Call (907) 331-4363 or text us a photo of the area to set up a free on-site estimate.