7mm Scoria is a lightweight volcanic rock aggregate made from naturally vesicular (porous) lava rock, screened to an approximate 7mm nominal size.
7mm Aggregate
7mm Aggregate, commonly known as ¼ minus, is a small, uniform crushed rock product designed for applications where a finer, smoother finish is required without sacrificing strength and stability. Produced by crushing hard rock down to an approximate 7mm nominal size, this aggregate consists of sharp, angular particles that interlock well while still allowing for drainage.
Additional Information
Additional information
The material typically appears in natural grey tones—light to mid-grey with occasional darker flecks—and presents a tighter, finer texture than 20mm aggregate. Its small size makes it an excellent choice for high-finish concrete, detailed landscaping work, and compact drainage layers where a more refined look and smoother surface profile are desired.
Key characteristics:
- Approx. 7mm angular crushed rock (¼ minus)
- Small, uniform particles for a smooth, refined finish
- Provides strength, stability, and good interlock
- Suitable for concrete, landscaping, and drainage applications
Usage
7mm Aggregate is widely used by concreters, landscapers, and civil contractors in both structural and aesthetic roles:
Concrete Production
- Used as a fine coarse aggregate in concrete mixes where a smoother surface is beneficial, such as exposed aggregate or detailed formwork.
- Helps produce dense, strong concrete with a refined finish compared to mixes using only larger aggregate.
Landscaping & Surface Finishes
- Ideal for paths, garden borders, and decorative surfaces where a tighter, more uniform stone texture is preferred.
- Can be used in between-steppers areas, decorative strips, and around features for a neat, architectural look.
Drainage & Bedding
- Suitable for shallow drainage applications, bedding around pipes, and as a finer drainage layer where larger stone would be visually or practically unsuitable.
- The small, angular particles provide good interlock and load distribution while still allowing water to pass through.
Under-Slab & Base Layers (Blends)
- Can be blended with other materials as part of a base or bedding layer below pavers, slabs, or concrete where a smooth, compactable crushed rock is needed.
Application Tips:
- When used as a base or bedding, place and compact in thin layers for maximum stability and even support.
- For concrete mixes, follow the engineer’s or supplier’s recommended mix design to achieve the required strength and finish.
- In visible landscaping applications, rake to a consistent level and thickness to maintain an even appearance.
20mm Scoria is a lightweight volcanic rock aggregate screened to an approximate 20mm nominal size.
20mm Aggregate is a crushed rock product engineered for strength, durability, and versatility across a wide range of civil, building, and landscaping...
