When You Need This Checklist
I manage purchasing for a mid-sized construction firm—about 300 people across two job sites. We handle roadwork, site prep, and general contracting. When I first took over equipment procurement in 2020, I assumed picking between a Dynapac compactor, a plate compactor, or a garbage truck was just about reading specs. Simple, right?
Turns out, that assumption cost us a $4,000 overtime charge on a project where we rented the wrong machine. This checklist is for anyone who buys equipment for construction teams where the operators know what they want but you, as the admin buyer, need to make sure the purchase actually fits the job, the budget, and the schedule.
Here are the 5 steps I use now. Follow these, and you’ll avoid the most common (and expensive) mistakes.
Step 1: Define the Application, Not Just the Machine
Operators will often come to you and say, "I need a Dynapac roller." Or, "Get me a plate compactor." But what they actually mean is, "I need to compact this specific material in this specific space."
Your first job is to translate their request into the application. Write down the following:
- Material type: Soil, asphalt, gravel, or refuse?
- Area size: Is it a 50-foot stretch of road or a 10×10 foot trench?
- Depth of compaction: Are we talking 6 inches or 2 feet?
- Proximity to structures: Can a large roller get close to a building foundation or edge?
The first time I skipped this, I ordered a large Dynapac vibratory roller for a job that was mostly narrow utility trenches. It was too wide to fit. The crew spent two hours hand-tamping—which, honestly, I should have known better. What I mean is, the machine isn't the requirement; the compaction goal is.
Step 2: Match the Machine to the Application
Once you have the application, matching the machine becomes clearer. Here's my quick decision tree, which, after 5 years of procurement, I've found to be 90% reliable:
For Large, Open-Area Compaction (Roads, Parking Lots)
Best fit: Dynapac road rollers (smooth drum or padfoot). If you're doing miles of roadway or large asphalt patches, a ride-on Dynapac is your best bet. They're fast, provide high compaction force, and are incredibly durable. If I remember correctly, our last large asphalt project used a Dynapac CC4200. It cost more to rent, but it finished in 4 days versus the 6 we'd budgeted for.
For Small, Tight-Area Compaction (Trenches, Edges, Backfill)
Best fit: Plate compactors (one-way or reversible). For trenches or tight corners, a plate compactor is what you need. A 500-600 lb reversible plate will handle most trench work. This is where I made my initial $4,000 mistake—I ordered a roller for a job that needed three walk-behind plates. The operators were polite about it, but I could tell they were frustrated.
For Waste Management or Site Cleanup
Best fit: Garbage trucks (roll-off or front-loader). This is the one that feels out of place on a list with compactors, but here's the thing: you can't compact refuse effectively if you can't move it. For construction sites, a dedicated garbage truck for debris removal is part of the workflow. If you're managing a site that generates significant waste (demo debris, packaging, etc.), the logistics of hauling it away with a pickup truck is a sinkhole of labor hours. A roll-off garbage truck service (or renting a bin) is often cheaper than paying crew overtime.
Step 3: Check the Logistics—Can You Actually Use It?
This is the step most admin buyers forget. You've picked the machine. Great. But can you get it to the site? On time?
- Transport: A large Dynapac roller needs a low-boy trailer. Do you own one? Will you have to rent one? That adds $500-$1000 to the cost.
- Operator training: Who's running it? Do they have the certification? We had a situation where an operator claimed he could run a specific model of compactor, but when it arrived, he'd only ever used a different brand. We lost half a day.
- Fuel/power: Diesel rollers need on-site refueling. Electric plates need a generator. Cords? Make a list.
I once ordered a 3-ton garbage truck roll-off service for a site in a city center without verifying access. The truck was too long to turn into the alley. That was an expensive and embarrassing call to dispatch.
Step 4: Compare Total Cost of Operation (TCO), Not Just Rental Price
Operators will tell you the rental price. Your job is to look at the total cost:
- Rental cost: Obvious. But don't forget insurance and damage waivers.
- Transport cost: As mentioned, this can be a shocker.
- Fuel/consumables: A plate compactor runs on gas or diesel. A Dynapac roller might burn through 5-10 gallons per shift.
- Labor cost: A smaller plate compactor might take twice as long as a roller to cover the same area. If crew time is $75/hour, the cheaper rental might actually cost you more in the end.
- Disposal cost: If you're using a garbage truck for debris, what's the dump fee? (which, honestly, varies wildly by location—like $40/ton vs $120/ton).
I have mixed feelings about always buying the cheapest option. On one hand, the budget is the budget. On the other hand, a cheaper rental that takes twice as long can make you look bad to your project manager. Per FTC guidelines (ftc.gov), be careful with claims like “most economical” on a quote—verify with data.
Step 5: Secure the Deal with a Fallback Plan
Once you've chosen the equipment, get the price locked in. But here's the pro move: ask the rental vendor for a backup recommendation.
Sometimes the Dynapac you need is already out on rent. If they say, "We have a similar model from another brand," ask for details. A 5-ton roller with 70-inch drum width might be interchangeable; an 8-ton roller with a 84-inch drum is not.
If I remember correctly, we once needed a specific Dynapac plate compactor for a foundation project. The vendor didn't have it, but they offered a Bomag model with identical specs. I called my lead operator, he gave it a thumbs up, and we saved a day of searching. Building that relationship with the rental desk saved us.
Common Mistakes to Avoid
- Assuming all compactors are interchangeable: A Dynapac roller for asphalt is NOT the same as a padfoot version for clay. Different drums, different compaction force.
- Forgetting about the garbage truck: I cannot tell you how many projects have been delayed because the site fills up with debris and there's no removal plan. A garbage truck service with a roll-off bin should be in your procurement checklist for any job generating waste.
- Skipping the site visit: You can't spec this from your desk. Walk the site or get a photo. I ask for photos of the edges and corners. That's where the plate compactor lives.
- Trusting a verbal promise: Get the rental delivery date in writing. Under federal law (18 U.S. Code § 1708), that's for mail, but for contracts, a signed confirmation is your only real protection.
Prices as of May 2024; verify current rates with your local vendor.
