Steel road plates are the temporary deck that lets traffic cross an open trench overnight. The sizes hired most often are 5 by 10 feet and 8 by 12 feet, an inch thick, and an inch of steel weighs roughly forty pounds a square foot, so the small plate is about a ton and the large one nearly two. They are hired by the week or the month rather than the day.
Size the plate to the trench, generously
A plate has to overlap solid ground on every side, not merely span the gap, because the edges of a fresh excavation break down under load. A foot of bearing each side is a common minimum and more is better on soft shoulders. That is why a three foot trench across a lane is usually covered with a five by ten rather than something cut to fit.
What one weighs, and how it arrives
At roughly forty pounds a square foot for inch plate, a five by ten runs near two thousand pounds and an eight by twelve close to four thousand. Nothing about that is a pickup job. Yards deliver on a truck with a knuckle boom crane and set each plate where it goes, then lift them again at collection, which is priced into the hire.
Holding it down once it is placed
A loose plate walks under traffic and becomes a hazard louder than the hole it covers. The usual methods are pinning it to the pavement, countersinking it into a milled recess, or ramping the edges with cold asphalt so vehicles do not slam the lip. Which one is required is set by the local permit rather than by the rental yard.
What hire costs
Plates are usually quoted per plate per week, commonly $50 to $150 depending on size and market, with monthly rates lower again and transport charged separately because of the crane truck. On a long utility job the delivery and collection often outweigh the plate hire itself, so it pays to take everything you need in one trip.
Questions people ask about steel road plates
How much does a steel road plate weigh?
About forty pounds per square foot at one inch thick, so a five by ten weighs around two thousand pounds and an eight by twelve nearly four thousand. Thicker plate is used for heavier loads or longer spans and scales up in weight from there.
How long can plates stay down?
As long as the permit allows, which in many cities is measured in days and requires the plate to be secured and the edges ramped. The rental itself is open ended and priced weekly, so the constraint comes from the road authority rather than the yard.
Do I need a permit to plate a trench?
On a public road, almost always, and the permit usually dictates plate thickness, how it is secured and what signage goes with it. Requirements vary city by city, so check with the road authority before the excavation starts rather than after the plate is down.
Can I collect road plates myself?
Not realistically. Each plate is one to two tons and has to be lifted precisely into place, which is why they are delivered by a crane truck and set by the driver. The lift is part of what you are paying for, at both ends of the hire.