How Do Plate Compactors Work?
A plate compactor is a useful construction tool for compressing soil and gravel to a flat surface. Learn more about plate compactors and their purpose
11:39 28 June 2019
There are often many steps toward completing a job right and messing up even one of them can cause the whole thing to implode.
For jobs like compaction, you need to know your way around a plate compactor or the very ground beneath you might throw you off.
What is compaction? What is a plate compactor?
Today we're going to guide you through this simple but important process so you can be better prepared in your next construction set up.
What Is a Plate Compactor
What is a plate compactor? A plate compactor is a machine made for dealing with rough and uneven patches of dirt and gravel. When you are paving a driveway or laying a foundation for a building, a plate compactor readies the soil beneath.
Plate compactors come in a variety of sizes and designs. They can range from a hand pushed machine used by one person to a massive industrial machine that is either automated or driven.
While plate compactors can have a wide number of different accessories and details, the basics of the machine stay the same.
A plate compactor works by vibrating or driving a flat metal plate against the ground over and over. This flat plate helps to compress and smoothen out the rough and uneven dirt.
Plate compactors work best on granular soil, such as sand and gravel. If there are major rocks, it can cause damage to a standard plate compactor.
Some designs have special ways to deal with this, but more often you will need to remove the rock.
When Do You Need to Compact
The main purpose of compaction is to prepare an area of soil or gravel for building over. This becomes more important the more other materials you place over the dirt, such as concrete.
The reason you need this process is that uncompacted dirt can have some major side effects due to weather and environment shifts.
Uncompacted dirt can shift and resettles due to water exposure as well as freezing and thawing cycles. This resettling process can make the area no longer flat, and if can cause major damage to concrete it is underneath.
Plate compactors have uses for smoothing out your sub-base or asphalt during the paving process or repair job. They can be invaluable for ensuring that your job finishes neat and flat. Otherwise, you may have to redo it.
Plate compactors are also best for getting into hard to reach areas. While an industrial roller may be the better, more efficient machine when dealing with a massive field or such, the small places need a plate compactor.
The Different Designs of Plate Compactors
A plate compactor comes in a variety of designs, each with their own niche they can fill. The three major designs are the single-plate compactor, the reversible plate compactor, and the high-performance/heavy-duty plate compactor.
- Single-Plate Compactor
A single-plate compactor's defining trait is the low level and ease of use they operate at. They are best for surface level compaction and small jobs.
They are the most common and popular form of compactor as they cover all the simple jobs that the typical homeowner might use a compactor.
They do have a downside in that they only move in a forward motion. You will have to keep this in mind as you operate the machine.
- Reversible Plate Compactor
Reversible plate compactors cover similar modes and uses of the single-plate compactors. Their main difference comes from their ability to operate going both forward and in reverse.
As well, they are able to penetrate much deeper into the soil. If you are doing deep down compaction, this will help, but if you only need a smaller layer of compaction, this might be too much.
Due to their increased versatility, reversible plate compactors are often a bit more expensive.
- Heavy-Duty Plate Compactor
These are the most intense of the plate compactors. The Heavy-Duty plate compactors are large, durable, and can compact ground far deeper than the single-plate compactor.
If you are looking for the most powerful machine for compaction without getting an industrial-sized roller, then this compactor will work.
For smaller areas in need of compacting, some models of this design may be too big or awkward to use.
How Does Compaction Work
Figuring out the logistics of a compacting job can be tricky. There are several steps to the process.
- Preliminary Checks and Excavation
As you start a paving and compacting job, you need to map out and plan each area you are working with. Knowing the entire dimensions of the area you are working with means you have clear boundaries you don't need to go beyond.
Once you have your area, you will need to excavate the area. Rocks, buried debris, and other dense materials can have nasty side effects to plate compactors, so removing them is very necessary.
You should excavate about 8 to 12 inches deep, depending on the project. If you are doing a driveway or patio, then that should be acceptable.
- Determining Your Sub-Base
After excavation, you will need to prepare for your sub-base. Sub-bases are materials like limestone or sandstone that provide a much more stable surface than raw dirt for paving.
Once you have your sub-base ready to put down, use the plate compactor to smooth out the excavation dirt. Sub-base works better on a flat surface.
Add about 4 to 8 inches of sub-base. Professionals call these sections lifts. Too much lift and it may be hard to compact but too little and it may get broken up and mixed with the dirt from compaction.
You will need to moisten the sub-base as well. Some plate compactors can do this with water tank accessories.
Be careful of the amount of moisture added. Too much can make the sub-base fall apart. Too little can make it hard to compact.
If you have excavated the full 12 inches, you may want 2 or more layers of sub-base, with each layer coated by a thin layer of compacted dirt. Remember to compact each layer before going to the next layer.
Once you have all your layers compacted, a 1-inch layer of sand bedding goes right over the top layer of sub-base. This will connect the sub-base to your paving and give the paving a softer surface to settle on.
Set the paving material over the area you want paved. You will need about 2 or 3 passes with a plate compactor to set the pavers.
- Final Compaction
Once the initial passes over the pavers is complete, you may want to inspect it for debris or signs of cracking.
A final compaction run, often about 2 or 3 passes, will help pressure any sand or unsolidified paving material into place for proper sealing.
Finding the Right Compactor for You
Now that you know the what, hows, and whys, now you need to find the right tool for the job. Here are a few things to consider when looking for a plate or Ground compactor for sale.
You also should consider what kind of uses you will have for your plate compactor. If you need it for a single job and nothing else, you might consider a rental plan.
- Style, Size, and Usability
Out of the 3 major designs talked about, the most common one you may find is the single-plate compactor. For most jobs, a single-plate compactor will be all that you may need.
Beyond the actual design, look at the shape and size of the plate compactor. Remember, this is something you will need to operate, so think about the position of the grips and how awkward the shape could be while moving it.
- Other Equipment and Materials
Paving a driveway takes more than a plate compactor. If you remember through the compaction process, there were many steps you will need to follow.
Excavation tools will be of great use to start the process.
While a shovel picks up dirt fine, you will need more substantial tools if you are looking to carve out a driveway in an afternoon. Not to mention removing large rocks as you come across them.
You will also need the materials for both the sub-bases and the paving itself.
There are tools that can help make the paving process smooth and easy, saving you a lot of headaches.
There are many parts and pieces that come with a plate compactor. If you are looking to buy one to own, you will need to understand how it works and what pieces will need replacing down the line.
From air filters to tank upgrades to hose replacements, all of these items will need proper consideration. When in doubt, get in touch with a hardware professional for more information.
A Job Well Done
Plate compactors are a versatile and important piece of construction equipment. Plate compactors help bridge the gap between needing a professional and making a big construction job a Do-It-Yourself.
When you are ready to get a compacting job done right, this guide will help you best understand what you need to do and what needs looking over.