It's 2 p.m. in late July. The air is 94°F, the mix coming off the screed is close to 300, and the black lot around it has been soaking up sun since 7. The screed operator has been standing over the heat for six hours. The new laborer you hired Monday is quiet, pale and has stopped sweating as much as everybody else.
Nobody on a paving crew works a hotter spot in town. Heat illness on a lot isn't bad luck. It's predictable, and so is most of what prevents it.
How to keep a paving crew safe in summer heat
Keep a paving crew safe in summer heat with four things: enough cold water on the lot for everyone to drink every 15 to 20 minutes, shade close to the work, real breaks that rotate people off the screed and the rakes, and a start time that gets the heaviest work done before the afternoon peak. Ease new and returning crew members into the heat over their first week, and teach everyone the signs of heat stroke, because it can kill someone in an afternoon.
Bring more water than you think
OSHA's heat guidance for outdoor work is to drink about one cup, 8 ounces, every 15 to 20 minutes during moderate work in the heat, even when you're not thirsty. That's 24 to 32 ounces an hour. Paving is not moderate work.
Do the arithmetic for your own crew. Say you run six people on a 10-hour day and plan for 32 ounces an hour each.
- Per person: 32 ounces × 10 hours = 320 ounces, which is 2.5 gallons
- For the crew: 2.5 gallons × 6 = 15 gallons
That's two big coolers, full, with ice, and a plan to refill them. A single five-gallon jug on the tailgate runs out before lunch.
Put the water where the work is, not at the truck at the far end of the lot. If getting a drink means a two-minute walk past the roller, people skip it. On long sweating days, have electrolyte drinks on hand too. Water replaces the fluid, but a full day of heavy sweating also costs salt.
Shade that's actually close
Shade doesn't have to be fancy. A pop-up canopy staked next to the work, moved as the paving moves, does the job. So does the cab of a truck with the air conditioning running. What matters is that it's close enough to use during a two-minute pause between trucks.
A few things that help on a paving crew specifically:
- Canopies on rollers. Roller operators sit in direct sun all day. If your rollers have canopies, keep them on.
- The right long sleeves. The crew needs long sleeves and long pants around hot mix, because asphalt burns. That doesn't mean heavy cotton. Light-colored, breathable work shirts keep the burn protection without cooking the person inside.
- Cooling towels and ice. Cheap, and they work. A cold towel on the neck during a break brings a raker's temperature down faster than standing in the shade alone.
Breaks that fit around the paver
The objection to breaks on a paving crew is always the same: the paver can't stop. The mix is cooling, the trucks are lined up, and the mat has to be rolled in its window.
The answer is rotation, not stopping. Use the gaps between trucks, and have one person who can step into any spot for 10 minutes. The screed operator steps off, the spare takes the screed controls or the rake, and the screed operator drinks and cools off in the shade. Then the next person. On a crew of six that's a full rotation every hour or so without the paver waiting on anybody.
Settle who rotates where in the morning, the same way you settle who does what on the crew. Watch the hottest positions most closely: the screed, the rakers working the edges next to fresh mix, and the person running a hand tamper or plate compactor.
One pay note that trips people up. Under federal wage law, short rest breaks, typically 5 to 20 minutes, are paid work time. A meal period can be unpaid only when the person is fully relieved of work, and it's typically 30 minutes or more. Don't dock a water break, and don't ask anyone to skip one to keep the paver moving. Some states have their own meal and rest break rules, so check yours.
Start early and finish before the worst of it
The easiest heat control you have is the clock. Most days, the hottest part is mid to late afternoon. A crew that starts at 6 a.m. and is off the lot by 2:30 p.m. misses a lot of it.
Before you move the start time:
- Talk to the plant. Ask how early they'll load out in July. Some plants open earlier in summer for exactly this.
- Check the town. Residential areas often have noise ordinances limiting how early equipment can run. Call the city before you pave a subdivision at 6 a.m.
- Ask the customer. Retail and office lots often prefer early work anyway, because the lot is empty before 9. A property manager may welcome a 5 a.m. start on a commercial lot.
For big commercial lots in the hottest weeks, night paving is worth a conversation. It needs lighting and traffic control, and the plant has to run at night, but it takes the heat off the crew and the lot off the tenants' business hours. Whatever start time you pick, a hot week still loses hours, so leave slack in the month the same way you leave room for rain days.
Ease people into the heat
New people are the ones at risk. OSHA points out that a large share of heat deaths happen in a worker's first few days on the job, before the body adapts.
The acclimatization schedule OSHA and NIOSH describe is a good starting point:
- New to the heat: no more than 20 percent of the usual time in the heat on day one, and add no more than 20 percent a day after that.
- Experienced, but coming back after a week or more away: about 50 percent on day one, 60 percent on day two, 80 percent on day three and full days from day four.
On a paving crew that means the new laborer spends part of the first days on lighter or shaded work: traffic control, spotting trucks, the tack sprayer early in the day. It also means a heat wave that arrives suddenly in June hits the whole crew like they're new, so ease back the first two hot days.
Pair every new person with someone experienced who's told to watch them. New people don't say they feel bad. They keep working to prove themselves.
Know the signs, and what to do
Talk about this at the morning safety talk on the first hot day, not after someone goes down.
Heat exhaustion: heavy sweating, headache, nausea, dizziness, weakness, irritability, thirst. Get the person off the lot into shade or an air-conditioned cab, give them water, loosen clothing, cool them with cold towels. Don't send them back to work that day. If they don't improve quickly, or they get worse, treat it as heat stroke.
Heat stroke: confusion, slurred speech, acting strangely, fainting, seizures, a very high body temperature. The skin may be hot and dry or still sweating. This is a medical emergency. Call 911. Cool them right away with water, ice and wet towels while you wait, and stay with them.
The laborer in the opening, quiet and pale and sweating less than the others, needed to come off the lot an hour earlier.
Check the rules where you work
OSHA expects employers to protect workers from recognized hazards, and heat is one. Its heat illness guidance and the OSHA-NIOSH Heat Safety Tool app are good places to start, and OSHA has been working on a federal heat rule, so check where that stands. California, Washington, Oregon and several other states have their own outdoor heat rules with specific requirements for water, shade and breaks. If you work in one of them, those rules are what an inspector will hold you to. OSHA and safety for paving crews covers the rest of what applies on a paving lot.
Questions contractors ask
How much water does a paving crew need in the heat?
Plan on about 24 to 32 ounces per person per hour, following OSHA's guidance of a cup every 15 to 20 minutes. For six people on a 10-hour day at 32 ounces an hour, that's 15 gallons.
Are water and rest breaks paid?
Under federal law, short breaks of about 5 to 20 minutes are paid work time. Meal periods can be unpaid only when the worker is fully relieved of duty. Some states add their own requirements.
How do you give breaks without stopping the paver?
Rotate people off one at a time during the gaps between trucks, with a spare crew member stepping into each position. The paver keeps moving and everyone gets time in the shade.
What temperature is too hot to pave?
There isn't one federal number. Watch the heat index rather than the air temperature, follow your state's heat rule if it has one, and shift the start time earlier as the heat index climbs.
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