Squeegee rock is a specialized grade of fine crushed aggregate material used extensively in construction and landscaping. It is classified purely by the size of its particles, making it highly effective for applications requiring superior drainage and a stable base layer. The name “squeegee rock” is largely regional, and the aggregate may be known by other names depending on the supplier or local building code.
Defining Squeegee Rock
The defining characteristic of squeegee rock is its precise physical size specification, generally described as a 1/4-inch minus aggregate. This means the material has been screened so the largest pieces are approximately one-quarter of an inch in diameter, with a range of smaller particles included. In construction, this grade is sometimes referred to as crushed fines or 10mm minus, placing it between concrete sand and traditional pea gravel in terms of coarseness.
The material earns its distinctive name because of its proficiency in shedding water quickly and cleanly, much like a squeegee blade clears a surface. This effectiveness is tied to the consistency of its grading and the exclusion of excessively fine materials like silt or clay.
Essential Physical Properties
The utility of this aggregate stems from the combination of its small particle size and its angular, crushed texture. Unlike naturally rounded pea gravel, squeegee rock pieces are fractured, allowing them to interlock tightly when compacted. This interlocking mechanism creates a firm, stable base that resists shifting and lateral movement, even under load.
The material’s excellent permeability results from a washing process that removes most fine dust and powder. The remaining aggregate creates numerous, connected void spaces, allowing water to pass through freely without compacting into an impermeable layer. This non-compacting nature ensures the material maintains its porosity over time, facilitating rapid water movement.
Key Uses in Building and Design
Squeegee rock is the preferred material for several applications requiring high drainage and structural stability. One of its main uses is as a bedding material for underground utility pipes, such as sewer lines or drainage tiles. The small, clean aggregate cushions the pipes while preventing the accumulation of water, which could otherwise lead to corrosion or structural stress.
In landscaping, it is frequently used as the sub-base layer beneath permeable pavements, patios, and walkways. Its porosity allows rainwater to infiltrate the ground naturally, reducing surface runoff and mitigating erosion. The material is also utilized as a filler around building foundations and retaining walls to relieve hydrostatic pressure by providing an escape route for groundwater, protecting the structure from moisture damage.