External Works · 10 checks

Paving & Roadworks
QA inspection checklist

Paving and roadworks quality audit.

Every check below carries what good looks like, when it passes, the standard it comes from and the defects that usually fail it. That guidance is what turns a tick-box into an inspection.

Sub-base & Base

  1. 1.
    Sub-base material matches specification
    What to look forSub-base material per SHW Series 800 — typically Type 1 (well-graded crushed rock 0/63 mm) or Type 2 (granular 0/40). Delivery note specifies SHW class. Visual grading shows full range from fines to maximum size. No clay lumps, organic material, or contaminants.
    Acceptable whenPer SHW Clause 803 (Type 1) / 804 (Type 2): grading envelope per Table 8/3, plasticity index zero for Type 1, ≤ 6 for Type 2. Frost-susceptible test (BS 812-124) where required. CE/UKCA mark per BS EN 13242.
    StandardSHW Series 800. BS EN 13242:2002+A1:2007 — Aggregates for unbound and hydraulically bound materials. BS 812-124 — Frost heave test.
    Common defectsType 2 supplied where Type 1 specified — strength insufficientExcess fines — frost-susceptible, pumping under loadOversize > 63 mm — voids in compacted layerRecycled aggregate without conformity to SHW Clause 710No delivery tickets — traceability lost
  2. 2.
    Compaction test passed
    Record: CBR (%)
    What to look forCompaction tested by nuclear gauge, sand replacement, or plate bearing test. Result against design CBR / refusal density. Frequency per SHW or project spec — typically 1 test per 500 m² minimum. No pumping or rutting under construction traffic.
    Acceptable whenPer SHW Clause 803.7 — sub-base compacted by method spec (number of passes per Table 8/4) or end-product (density / CBR). Design CBR typical: 30% post-compaction for Type 1 sub-base. No visible movement under construction traffic.
    StandardSHW Clause 803. BS 1377-9:1990 — In-situ tests. DMRB CD 225 — Pavement design.
    Common defectsCompaction test failed but next layer placed anywaySpot test does not represent area — biased locationSub-base pumping under traffic — sign of trapped waterDensity below MDD — surface course will rut early in lifeTest frequency below spec
  3. 3.
    Levels and falls correct
    Record: Fall (1 in ?)
    What to look forLevels surveyed at multiple points across each section. Crossfall checked across road / path width with calibrated level. Falls drain to gullies / outfalls — no flat zones or back-falls. Vertical curves smooth — no sudden grade changes.
    Acceptable whenPer SHW Clause 702 / DMRB: surface tolerance ±10 mm of design level for road; ±15 mm for footway. Crossfall typically 2.5% (1:40) for road, 1:60-1:80 for footway. No back-fall away from gullies.
    StandardSHW Clause 702. DMRB CD 116 — Geometric design of carriageway. SHW Series 800 (sub-base levels).
    Common defectsLevel high — surface course laid thinner than designLevel low — extra surfacing required, cost over-runCrossfall inadequate — water ponds across roadBack-fall to gullies — water flows the wrong wayVertical kink at sub-base joint — telegraphs through surface course

Surface Course

  1. 4.
    Material type and thickness correct
    Record: Thickness (mm)
    What to look forSurfacing material per design — AC10/AC14 (asphalt concrete), SMA (stone mastic asphalt), HRA (hot rolled asphalt), or block paving. Mix designation on delivery ticket matches spec. Compacted thickness measured by depth gauge / cores. Layer brought up on top edge of previous layer.
    Acceptable whenPer SHW Clauses 911/912/942/943 — material type and grade per design, including binder grade and PSV (Polished Stone Value). Compacted thickness ±10 mm of design (binder course) / ±5 mm (surface course). Cores taken at 1 per 1000 m² typical.
    StandardSHW Series 900 — Bituminous bound materials. BS EN 13108-1 (AC) / -5 (SMA) / -4 (HRA). DMRB CD 226 — Pavement materials.
    Common defectsAC10 surface where AC14 specified — surface texture / durability differentPSV too low — surface polishes, skid resistance failsSurface course thinner than spec — durability halvedWrong binder grade (40/60 instead of 70/100) — cracking in coldNo delivery ticket retained — traceability gap
  2. 5.
    Joints properly formed and sealed
    What to look forLongitudinal joints between adjacent paver passes hot-vertical or stepped, sealed with bitumen joint paint. Transverse joints (day joints) cut back to vertical face. Joints rolled with edge of roller. No "fanning" or visible step at joint.
    Acceptable whenPer SHW Clauses 902 / 903: joint vertical and tightly bonded; bond coat (typically PMB tack) applied to vertical face before adjacent lay. Joint level no more than ±3 mm step. SMA joints sealed with bitumen / proprietary tape (Pavejoint).
    StandardSHW Clauses 902 / 942. NRSWA SROH for utility reinstatement joints.
    Common defectsCold joint — adjacent passes failed to bond, longitudinal crack within 1 winterStep at joint — lazy raking, water entersNo tack to vertical faceTransverse joint not cut back vertical — feathered edge ravelsJoint not rolled — surface texture different from field
  3. 6.
    Surface regularity within tolerance
    Record: Deviation (mm)
    What to look forSurface regularity checked with 3 m straightedge or rolling straightedge. Measured at multiple positions in each direction. No rocking edges, no birdbaths > 5 mm. Long-wave regularity verified for adopted highway with rolling straightedge.
    Acceptable whenPer SHW Clause 702.5 / 921: 3 m straightedge tolerance ±3 mm (carriageway), ±6 mm (footway and access road). Rolling straightedge for high-speed roads. No abrupt changes that cause vehicle bounce.
    StandardSHW Clause 702. SHW Clause 921. BS 1230 — straightedge. DMRB CD 226.
    Common defectsBirdbaths from poor compaction temperatureLong-wave undulation — paver auger uneven feedStep at gullies / manholes — ironwork not set true to surface3 m straight edge rocks > 6 mm — non-compliant
  4. 7.
    Core samples taken (if required)
    What to look forCores cut at locations agreed with engineer (typically 1 per 1000 m²). Core measured for compacted thickness and assessed for compaction (air voids). Lab tested for binder content and grading per spec. Holes reinstated immediately with hot mix.
    Acceptable whenPer SHW Clauses 929 / 930: core compaction expressed as PRD (% of refusal density) — typically ≥ 93% for surface course. Air voids 4-7% target. Binder content within ±0.3% of mix design. Core hole reinstatement same mix.
    StandardSHW Series 900. BS EN 12697-6 (PRD). BS EN 12697-39 (binder content).
    Common defectsCores not taken — compaction unverifiedCores below 93% PRD — premature failure likelyCore hole reinstated with cold patch — water ingress, weaknessAir voids > 8% — water entry, oxidationCores taken only from easy areas — skewed sample

Street Furniture & Markings

  1. 8.
    Kerbs aligned and level
    What to look forKerb line straight when sighted along run; smooth radii at curves. Top of kerb level / matches design profile. Kerbs bedded on concrete with full backing haunch. Joints consistent (3-5 mm typical) and pointed. Transition kerbs at dropped crossings.
    Acceptable whenPer SHW Clause 1101: alignment ±3 mm in 3 m run for straights; smooth tangent at curves. Top level ±6 mm of design. Bedding mortar / concrete C20/25 per Clause 1102. Backing haunch 100 mm minimum.
    StandardSHW Series 1100 — Kerbs, footways, paved areas. BS EN 1340 — Concrete kerbs. BS 7263-1 (precast).
    Common defectsWavy kerb line — fitter not using string lineTop of kerb steps at jointsNo backing haunch — kerb tilts under trafficJoint > 10 mm — looks rough, weeds growDropped crossing transitions abrupt
  2. 9.
    Drainage gullies clear and at correct level
    What to look forGully gratings set 3-6 mm below adjacent road surface so water enters readily. Frame bedded in mortar, no rocking. Gully chamber clear of debris. Connection to drain run has design fall. Anti-siphon trap (if specified) intact.
    Acceptable whenPer SHW Clause 511 / DMRB CD 526: gully top 5 mm below carriageway; level checked with straightedge across gully and adjacent surface. Capacity sized for catchment per Highways DMRB / Sewers for Adoption.
    StandardBS EN 124 — Gully tops and frames. SHW Clause 511. DMRB CD 526 — Spacing of road gullies. Sewers for Adoption 7th Ed.
    Common defectsGully proud of surface — water passes by, pondingGully flush with surface — water does not enter readilyFrame loose / rocks — fail under trafficGully blocked with construction debrisGully spacing too far — ponding between
  3. 10.
    Line markings and signage correct
    What to look forRoad markings per TSRGD (Traffic Signs Regulations and General Directions). Line widths and lengths match design. Thermoplastic well bonded — no lifting at edges. Retroreflectivity tested at sample points. Signs to TSRGD type and reflectivity class.
    Acceptable whenPer TSRGD 2016 and SHW Clause 1212: line width and pattern per drawing; retroreflectivity ≥ 100 mcd/m²/lux (Class B) typical; thermoplastic to BS EN 1871. Signs to BS 873 / Class RA1 or RA2 per location.
    StandardTSRGD 2016 — Traffic Signs Regulations. SHW Clauses 1212 / 1213. BS EN 1436 — Road marking materials performance.
    Common defectsLine widths wrong — non-compliant under TSRGDThermoplastic lifting — substrate not primedSignage RA1 used where RA2 demanded — visible at lower distanceMarkings on poor surface — premature lossCat eyes (where required) missing or wrong colour

Questions people ask

What is a paving & roadworks QA inspection for?

To record that the work was checked against the specification before it was covered up or handed over: a pass or fail against each item, a measurement where one matters, and a photo where it failed. It is the evidence a client's quantity surveyor or clerk of works asks for, and the thing that settles the argument at final account.

What standards does this checklist check against?

Each item names its reference. On this checklist that includes SHW Series 800. BS EN 13242:2002+A1:2007, SHW Clause 803. BS 1377-9:1990, SHW Clause 702. DMRB CD 116, SHW Series 900, SHW Clauses 902 / 942. NRSWA SROH for utility reinstatement joints., SHW Clause 702. SHW Clause 921. BS 1230. The contract specification and the approved drawings always take precedence over a general standard; where they say something stricter, inspect to that.

Who signs a QA inspection off?

The person who carried out the check, named and dated, and where the contract calls for it the client's representative as a witness. The signature records that the check was done and what was found. It is not a warranty of the work.

How many items are on it, and do I have to use them all?

10 checks across 3 sections. Delete what does not apply to the job and add anything the specification asks for that is not here. A checklist that has plainly been thought about carries more weight than a long one nobody read.

Is this useful for a subcontractor as well as a main contractor?

More so. The subcontractor is the one who gets asked to come back and open something up. A signed inspection sheet with photos at the time is the cheapest insurance on a construction site.

Run this inspection on a phone

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