The minimum thickness of bituminous surfacing required by S1.7.1 for reinstating immediate works is 40 mm. A greater thickness may be required in areas subject to frequent or heavy traffic if further remedial works are to be avoided during the 10 days permitted duration of immediate works. A temporary reinstatement may be used to fill an excavation before the apparatus is installed. The use of temporary reinstatement allows trafficking:
- Before the bound layers are fully excavated and when the old backfill, surround and apparatus are in place; or
- Where there is a delay in placing the bound layers of a permanent reinstatement.
Temporary reinstatements may be used:
- For delays encountered during emergency or planned works (e.g. waiting for specialist staff or equipment to arrive)
- On weekdays if work is limited to weekends
- At weekends and public holidays if work is restricted to weekdays
- For special events (e.g. parades, market days) when road plates are not appropriate.
The main factors to be considered for temporary reinstatements are trench volume, depth and shoring, materials availability, effect on apparatus, placement and compaction, removal and storage, asphalt specification and layer thickness.