Flexible and composite roads (S6)
Micro trenching (S6.6) Backfilling and reinstatement
Backfilling and reinstatement
S6.6.13 Once the duct/cable and locating strips have been installed, the trench must be reinstated in two or three courses, as follows.
Course 1 (conditional only – see below) – granular bedding material
Course 2 – indicator infill material
Course 3 – surface infill material
S6.6.14 Where the depth of the micro trench after installation of the duct/cable is greater than the adjacent depth of bound materials, granular bedding material or indicator infill material must be used up to the base of the adjacent bound layers.
S6.6.15 The indicator and surface infill material must be used within the bound materials.
S6.6.16 The minimum combined thickness of courses 1, 2 and 3 above the apparatus is 175 mm for roads and 100 mm for footways, footpaths and cycle tracks.
S6.6.17 If the depth of the micro trench is fully within the bound layers after installation of the duct/cable, only indicator and surface infill material need to be used.
S6.6.18 Granular bedding is not permitted within the bound layers of the adjacent structure.