Q&A: Top tips on using compactors

Compactors are a heavy-duty type of construction equipment used to create flat, hard and stable ground surfaces for construction. Compacting serves to compress soil, reduce the volume and prevent settlement. Compacting also increases soil density for improved load bearing capacity; and provides the necessary stability to prevent foundation erosion; cracks forming in slabs; and leaks or breaks in underground pipes. 

Here we introduce some popular types of compactors, and answer some frequently asked questions – to help you get the most out of your next compactor hire.

When is compaction necessary?

Soil must be compacted to provide stability before the construction of roads, pathways, building foundations and other structures. Proper soil compaction is also necessary when laying pipe underground, to:

• Maintain the correct elevation (or grade) of the pipe bed
• Evenly distribute loads from embedment and backfill above. 

Does soil need to be wet to be compacted?

Wetting soil can reduce the amount of dust produced during compaction. In some cases it can also improve the quality of the compaction by helping the soil particles slide together more easily, However this step isn’t always necessary. 

• Granular soils with little or no clay can be compacted wet or dry. 
• Soils containing clay do benefit from being wet before compaction. 

Can gravel be compacted?

Gravel can be compacted into lower layers of soil to allow for construction work above, or to keep the gravel in pathways and driveways firmly in place. For best results use a forward plate compactor and apply a fine mist before use to weigh down any dust.

Can compactors be used in small or confined spaces?

Tamping rammers are ideal for compacting soil and backfill in confined spaces – like trenches and deep excavations. The smaller plate size on tamping rammers creates a direct force for deeper and more focused compaction. Always brush up on your safe work practices before entering confined spaces.

Can compactors move in more than one direction?

Yes! Reversible plate compactors allow multi-directional movement (forwards and backwards). This feature is particularly useful when working on large areas, as well as working in trenches and other narrow workspaces where it is difficult to turn compactors around. 

What are the main types of compactors?

Plate compactors and rammers like these are widely used for small construction and landscaping tasks:

• Forward plate compactors – These are used for compacting thin layers such as road base and asphalt. 
• Reversible plate compactors – Used for compacting larger areas and also trenches with forward and reverse directional capabilities.
• Tamping rammers – Ideal for use in confined spaces such as trenches and deep excavations for compacting soil and backfill.