A plate compactors is a construction equipment used to compress some types of soil and gravel for construction projects that require a stable subsurface. Plate compactors come in a number of designs with different accessories, though the major features are stable. The core of the machine is a heavy, flat plate that rests on the ground when the machine is off. The plate is driven or vibrated up and down with either gasoline or diesel engines.

Compaction of sand before the construction  road
credit: Pawel_Kisiolek/iStock/Getty Images
Plate compactors are used in construction.

Background

Why They Are Used

A plate compactors is used to compacts soil a small driveway or patio. If the disturbed soil is not properly compacted, it can create serious problems after the fact. For example, as the un-compacted soil shifts and settles from exposure to water, freezing and thawing cycles and pressure from above due to vehicles or foot traffic, it can lead to unstable and uneven surfaces.

How They Work

As the machine runs, the heavy plate on the bottom of the machine moves up and down quickly. The combination of rapid impacts, plate weight and impact force forces the soil underneath to compact or pack together more tightly. Plate compactors are at their best when they are used on granular soil types, such as those that have higher sand or gravel content. In some cases, it is beneficial to add some moisture to the soil prior to using the plate compactor. Two to four passes over the soil is generally sufficient to achieve proper compaction, but the compactor manufacturer or rental establishment should be able to provide some guidance on a case-by-case basis.