Street works · England
O4 — Reinstatement of Sub-base & Base in Non-bituminous Materials
Non-bituminous sub-base and base reinstatement: preparing the backfill layer beneath, the materials permitted at each level, and laying and compacting them to the SROH.
Who holds this certificate
Operatives reinstating sub-base and base layers.
What it covers
3 topics, 69 questions between them.
Preparing the Backfill Layer
14 questions · 1 with a diagram
Sub-base, Base Materials & Safe Working
30 questions · 4 with a diagram
Laying & Compaction
25 questions · 2 with a diagram
Find It in the SROH
Open-book questions are not really memory tests — they test whether you can find the right page quickly. These 10 drills give you a heading and ask which document and section it sits under, so looking things up under time pressure becomes automatic.
Try 3 drills freeThe theory test
O4 is assessed by a theory test of 20 multiple-choice questions in 45 minutes. You need 16 out of 20 to pass. The app draws a fresh mock from this certificate's own bank each time and marks it against that pass mark.
Format described as published at the time of writing — confirm it with your assessment centre before you sit the test.
Written against
Every O4 question cites one of these, and the explanation names the clause or paragraph so you can check it yourself.
- Specification for the Reinstatement of Openings in Highways (SROH)
- Safety at Street Works and Road Works (the Red Book)
- HSG47 — Avoiding danger from underground services
- Streetworks UK Volume 1
- DfT qualifications guidance
- New Roads and Street Works Act 1991
- The Street Works (Qualifications of Supervisors and Operatives) Regulations
NRSWA Street Works Revision is independent revision material. It is not affiliated with, endorsed by or approved by HAUC(UK), SWQR, any awarding organisation or the Department for Transport, and it does not award a qualification or a card.