Sub-base / Laying Course

Type
Description

Roadstone offers a full range of laying materials to ensure you have what you need to complete your project.

Sub-base

Materials available loose or in 1 tonne bags

Typically a sub-base of compacted Clause 804 or similar, between 150mm and 300mm deep will be sufficient for most applications, depending on soil type, depth of build-up required
and loading that will be applied to the finished surface.

For footpaths around dwellings, material conforming to Annex E of SR21:2004+A1:2007 “guidance on the use of I.S. EN 13242:2002 – Aggregates for Unbound and Hydraulically Bound
Materials for use in Civil Engineering Work and Road Construction (incorporating amendment 1:2007 --- (4/40mm coarse aggregate, or suitable Clause 804 material).

The sub-base should be compacted using a vibrator or roller to within 10/15mm of level required. (40mm + depth of paving unit below finished level).

Falls should be built into the sub-base and the area should be free draining. A saturated sub-base and laying course is one of the main causes of failure and rutting.

Before spreading the laying paving grit sand, the area should be inspected and no area of the finished level of the base course should be more than the depth of the block +40mm, especially around manholes, kerbing and other obstacles.

Laying Course

Paving Grit

Materials available loose or in 1 tonne bags

The laying course should be a washed course grit sand complying with the requirements of Tables D1 & D2 of annex D of BS 7533 Part 3.

This should be 40mm in thickness after final compaction.

Pay particular attention to the setting of the bedding course, as the finished surface of the paving will mirror this layer. Ensure correct falls are maintained. Use screeding rails to ensure a correct surface level.

This can be laid either partial pre-compaction or compacted after laying.

Do not walk on surface after screeding / laying sand.

Mortar sand

Materials available loose or in 1 tonne bags

If laying Natural Stone products they must be laid on a bed of mortar.

Cement

Materials available in 25Kg bags