#7 limestone, also known as #7 stone, washed limestone, clean crushed limestone, or limestone drainage stone, is a clean, angular aggregate commonly used for drainage, construction, and landscaping projects. It typically consists of medium-sized limestone pieces approximately 1/2 inch to 3/4 inch in size, although exact gradation may vary by quarry and local specification.
Because the stone is washed and contains little to no dust or fines, it leaves open spaces between the particles that allow water to flow through efficiently. Its crushed, angular edges help the limestone interlock and stay in place more effectively than smooth, rounded gravel, providing a dependable combination of drainage, stability, and durability.
#7 limestone is popular because its manageable size makes it easy to install around pipes, foundations, retaining walls, and other structures. It is large enough to maintain consistent water flow but small enough to spread evenly and fit into narrower drainage trenches. Its clean appearance also makes it suitable for visible landscape and hardscape applications where both performance and appearance matter.
Common Applications of #7 Limestone
- Retaining wall backfill
- Pipe bedding and utility trenches
- Perimeter foundation drainage
- French drains and drainage systems
- Septic and leach-field stone
- Drainage beneath patios and concrete slabs
- Decorative landscape beds
- Hardscape accents and erosion-control areas










