Sub-base material is produced by crushing either limestone or granite rock.
The sub base is designed to evenly spread the load on traffic bearing areas such as pavements and roads. Made up of a load-bearing layer of aggregate, the sub base is laid on the sub-grade layer below. It is the main load-bearing layer in the construction of roads and pavements. The type of sub base is extremely important for the longevity and quality of the highway. The sub base distributes weight over a wide area, thus reducing settling of the surface. It’s the interlocking nature of the sub base particles that distribute the weight in multiple directions instead of directly downwards. When the top surface needs to be replaced, a good quality sub base may not need to be replaced at the same time. Often the top surface can be stripped and replaced without needing to reinstall the sub base, providing it is still in good enough condition. This of course can save a lot of time and money.
A sub base layer works by distributing weight over an area. The interlocking capability of certain types of aggregates means that, even with a relatively thin sub base layer, the ability to carry heavy loads can be improved.
Soils and Stone supply high-quality sub-base limestone and granite aggregate including Type 1 SHW Clause 803 (formerly MOT Type 1) and Type 3 Open Graded SHW Clause 805. Read on to see our full product range.
Soils and Stone supply Type 1 quarried primary aggregate to the Highway Agency’s Specification. Type 1 is a granular, well-graded material sized from 63mm to dust, but with most of the material sized at 31.5mm to dust.
Available both as a limestone or a granite, Type 1 SHW Clause 803 (formerly MOT Type 1) is widely used as a sub-base in the construction of roads, car parks and pathways. The mixture of stone and fines compacts to ensure minimal voids and provides a strong and durable sub-base.
Type 3 Open Graded SHW Clause 805 Sub Base is a pure crushed stone, ranging in size from 40mm down to dust, but with a reduced (not zero) fines content.
Available both as a granite or limestone, Type 3 Sub Base is widely used as a sub-base material for projects where a lower fine content is required for improved drainage. These include sports pitches, equestrian centres, driveway/hard standings and roads.
Soils and Stone supply Type 3 Open Graded SHW Clause 805 Sub Base quarried primary aggregate to comply with Highways Agency Clause 805 (SHW Clause 805).
Available as either granite or limestone, this is a crushed stone with no fines that ranges in size from 40mm–75mm. When compacted, it provides a hard-wearing and well-drained sub-base for use in roads, paths, drainage ditches, sport pitches, etc.
Available as either a granite or limestone, our 50mmm clean stone is screened to remove the fine content. When compacted it provides a hard-wearing and well-drained sub-base for use in roads, paths, drainage ditches, sport pitches, etc.
Scalpings are typically used as a medium-quality backfill to structures or as a sub-base material for access paths, car parks and driveways. The can be used as an alternative to Type 1 SHW Clause 803 (formerly MOT Type 1) for light-use applications or where a lower load bearing capacity is acceptable.