The estimate is the job
Everything that happens on a paving job gets decided in the estimate. The tons you order, the trucks you book, the crew days you plan and the price the customer signs all come from a sheet somebody filled out before anyone touched the lot. When a job loses money, it's usually not because the crew paved slow. It's because a number on the sheet was guessed instead of measured.
This is how to build a paving estimate from measured numbers. It's written for a parking lot, because that's most of the work, but a driveway or a street runs the same way with different quantities.
Step 1: Walk the lot and measure it
Get a net square footage you'd bet money on. Walk it with a wheel, or measure it from an aerial view and then walk it anyway. Break odd shapes into rectangles and triangles and add them up. Subtract what you won't pave: islands, concrete pads, dumpster enclosures, anything the customer wants left alone.
While you're out there, write down what the wheel can't tell you:
- Condition. Alligator cracking, ruts, birdbaths, raveling at the edges. These decide whether the job is an overlay, a mill and fill or a full-depth rebuild, and each one is a different estimate.
- Grade. Curbs, doors, drain structures, and where the lot meets concrete. If there's no room to come up, you're milling.
- Access. Can a tri-axle get in and turn around? Can the paver come off the lowboy at the entrance? Is there somewhere to stage?
- Base. Probe a couple of soft spots. Soft base is the change order everybody has seen, and the time to price it is now.
- Edges and structures. Linear feet of curb line, the number of manholes and valve boxes, catch basins that need adjusting.
This walk is where accurate estimates come from. Everything after it is arithmetic.
Step 2: Decide what you're selling
Before you figure anything, decide what the job is. A 2-inch overlay, a 2-inch mill and fill, and 3 inches over new base after full removal are three different jobs on the same lot, and the customer often doesn't know which one they need. That's your call to make and explain.
Write it in plain terms: lift thickness in inches, mix type, milling depth if any, tack, base repair as a unit price, striping. That becomes the proposal, and later it's what a change order gets measured against.
Step 3: Turn area and depth into tons
Hot mix is bought by the ton, so the estimate has to get there:
area (sq ft) × depth (in) ÷ 12 × unit weight (lb per cu ft) ÷ 2,000 = tons
Dividing by 12 turns inches into feet. Compacted hot mix is often figured at 145 pounds per cubic foot, but the mix design from your plant has the real number, and it might be 148. Ask.
For a 30,000 square foot lot at 2 inches: 30,000 × 2 ÷ 12 = 5,000 cubic feet. At 145 pounds, that's 725,000 pounds, or 362.5 tons.
Now add a waste factor. The formula assumes a flat surface at exactly 2 inches. Real lots have ruts that fill before the lift starts, edges that get raked heavy, and a bit of depth creep at the screed. A common rule of thumb is around 5 percent on a freshly milled surface and closer to 10 on an overlay of a rough lot. Your own plant tickets from past jobs are a better source than any rule of thumb, which is the best reason to keep them.
If the job has two lifts, binder and surface, figure each one separately. They're different mixes at different prices.
Step 4: Price the mix and the trucking
Call the plant for today's price per ton on the mix you specified. Prices move with the price of liquid asphalt and with the season, and the number from April isn't the number in August. If the job is weeks out, ask how long the plant's quote holds.
Then trucking, which you should work out rather than guess. Tons divided by payload gives loads. Loads times the round trip gives truck hours.
Say your tri-axles carry about 16 tons (check your own legal payload). The 362.5-ton job is 23 loads. If the plant is 40 minutes away and loading plus dumping takes 25 minutes, each round trip is 105 minutes, so that's about 40 truck hours. Move to a plant 15 minutes away and the round trip is 55 minutes, which comes to about 21 truck hours. The distance also decides how many trucks you need running to keep the paver from stopping.
Then the rest of the material: tack by the gallon, stone for base repair by the ton, crack sealant if it's in the job, paint for striping.
Step 5: Crew and equipment
Build labor from crew days. A paving crew might be a paver operator, a screed operator, two or three on the rakes and lutes, two roller operators and a foreman. Figure how many tons that crew places in a day on this kind of lot. Open lots go fast, and lots with a lot of hand work go slow. That gives you crew days. Multiply by the loaded hourly cost of each person, meaning wages plus payroll taxes, workers' comp and benefits.
Equipment goes in the same way: paver, two rollers, skid steer, and the lowboy to move it all. Use what the equipment costs you to own and run per hour, not a rental rate, unless you're actually renting.
Then add the days that aren't paving days: prep and cleaning, milling if you do your own, base repair, and moving the equipment in and out.
Step 6: Subs and pass-through costs
Milling, striping, trucking and sometimes concrete get subbed out. Get the sub's quote and mark it up. You're managing the sub, carrying the risk if they don't show, and often paying them before the customer pays you. Price that in.
Traffic control, permits and testing are pass-throughs when the job needs them. Put them on the sheet with a markup, or exclude them in writing.
Step 7: Overhead and margin
Every job has to carry its share of the shop, the trucks, the office and the insurance. The simplest way to set that share is from last year's books.
Say last year's overhead was $300,000 and the direct cost of all your jobs was $1.5 million. Overhead ran 20 cents on every dollar of direct cost. A job with $40,000 of direct cost has to bring in $8,000 toward overhead before it makes a dime. If you want $5,000 of profit on it, the price is $53,000.
Know the difference between markup and margin. That $53,000 job is a 32.5 percent markup on direct cost ($13,000 ÷ $40,000) but a 24.5 percent gross margin ($13,000 ÷ $53,000). Mix those two up and you'll price every job lower than you meant to.
Set the margin your own numbers say you need. Then divide the total by net square feet as a sanity check. If the unit price is far off what you usually charge for this kind of work, something's missing. Go find it.
Step 8: Write a proposal you can stand behind
The proposal is the estimate the customer can read. Put the quantities on it: square feet, lift thickness, tons, milling depth, stall count. Put unit prices on it for the unknowns: base repair per square foot, extra mix per ton, manhole adjustments each. And write the exclusions.
A proposal with quantities on it does two things. It shows the customer what they're paying for. And it makes the change order simple arithmetic when the mill finds soft base at 7 a.m.
After the job, check the estimate
Add up the plant tickets. Add up the crew hours. Compare both to the sheet. If the tickets say 400 tons and you estimated 362.5, you were about 10 percent heavy, and if you allowed 5, your waste factor for that kind of job is wrong. Next spring's estimates will be wrong the same way until you fix it.
Where Pavr fits
Pavr is job management software for paving, sealcoating, striping and concrete contractors. In Pavr you draw the lot on the satellite view or on the PDF plan, and the square footage goes straight onto the estimate. Start from the built-in asphalt services, add your plant price and crew rates, and the estimate shows your cost and margin before you send it.
The customer sees the quantities on the proposal and signs it on their phone from the email. If the plant raises its price after that, the proposal you sent doesn't move. Once the job runs, approved crew hours, the material off the daily log and sub invoices post against the lines you estimated, so next spring's waste factor comes from your own tickets. See how estimating works.
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