K-5 for Base and Drainage
K-5 sand represents the highest tier of soil permeability classification, engineered for rapid-flow septic systems and heavy-duty drainage applications. With an ultra-fast percolation rate exceeding 20 inches per hour, it’s the top choice for projects demanding maximum water evacuation speed. This aggregate material is available for bulk pickup or delivery.
Why Choose K-5 Sand
K-5 sand is valued for its maximum void space and ultra-clean composition. With a percolation rate greater than 20 inches per hour (less than 3 minutes per inch), water moves through it immediately with virtually zero risk of internal compaction or hydraulic resistance.
This drainage sand is thoroughly washed to remove fine silts, clays, and debris. It’s the preferred aggregate choice for high-impact stormwater mitigation, massive retention basin under-drains, and complex commercial foundation drainage where rapid water evacuation is mandatory.
Material Type: Heavily screened drainage sand.
Percolation Rate: Approximately 6 to 20 inches per hour (3 to 10 minutes per inch).
Fines Content: Very low silt and clay content for maximum, long-lasting permeability.
Drainage Characteristics: Rapid drawdown with excellent structural pore retention.
Compaction: Resists compaction under mild, long-term soil pressure, preserving infiltration capacity.
K-5 sand is commonly used across a range of extreme-flow drainage and specialized septic applications.
Septic Systems: Pressure-dosed distribution networks, sand filter configurations, and hydraulic receiving layers for pre-treated effluent.
Stormwater Management: High-impact stormwater mitigation and retention basin under-drains.
Construction: Commercial foundation drainage requiring rapid water evacuation.
Drainage: Extreme-flow drainage systems where standard sand grades cannot keep pace.
Utility Projects: Heavy-duty drainage layers for large-scale infrastructure work.
Common Uses
• Pressure-dosed septic distribution networks
• Sand filter systems
• Stormwater retention basin under-drains
• Commercial foundation drainage
• High-impact stormwater mitigation
• Hydraulic receiving layers for pre-treated effluent
• Utility trench backfill
What is K-5 sand used for?
K-5 sand is commonly used for pressure-dosed septic systems, sand filters, stormwater retention basins, and commercial foundation drainage where rapid water evacuation is required.
What is the percolation rate of K-5 sand?
K-5 sand has a percolation rate greater than 20 inches per hour, equating to less than 3 minutes per inch.
Can K-5 sand be used in a standard septic drain field?
K-5 sand is rarely used as a standalone treatment bed in standard gravity-fed systems, since water moves through too quickly for adequate pathogen treatment. It's best paired with engineered systems like pressure-dosed networks or sand filters.
How is K-5 sand different from K-4 sand?
K-5 sand drains even faster than K-4 sand, exceeding 20 inches per hour compared to K-4's 6 to 20 inches per hour range. This makes K-5 suited for more extreme-flow applications but requires specialized system design for septic use.
Is K-5 sand the same as mason sand?
In some regional markets, "K-5" is used to describe ultra-clean washed mason sand. Always verify with your supplier that you're getting the coarse drainage aggregate rather than a finer masonry mix.
Does K-5 sand compact well?
K-5 sand is highly resistant to compaction due to its uniform coarse particles and lack of fines, maintaining maximum void space and drainage performance over time.
Is K-5 sand suitable for stormwater management?
Yes. Its ultra-fast percolation rate makes it ideal for stormwater retention basin under-drains and other high-impact stormwater mitigation projects.
