The three fronts of control
Quality control is organised on three complementary fronts, which the technical regulations develop for each material and unit. All three are programmed before works start rather than during them.
Product reception control: nothing enters the site unverified. For products with markings and conformity documentation, the check is documentary; for those the regulations subject to experimental control, concrete as the archetypal case, reception includes testing at regulated frequencies.
Execution control: units are checked during their realisation, setting-out, reinforcement before concreting, welds, waterproofing before covering, services before closing, with the operating rule presiding over the whole system: what will end up hidden is verified before being covered. Verification before covering is the cheapest check in the whole system.
And the control of the finished works: the final service tests, watertightness, pressure, functioning of services, verifying the result as a whole. Their results form part of the building logbook.
| Control front | What it verifies | Timing |
|---|---|---|
| Reception control | That products arrive compliant, with marking and documentation | As each material arrives |
| Execution control | Setting out, reinforcement, welds, waterproofing and services | Before the unit is concealed |
| Finished works control | Final service tests, watertightness, pressure and functioning | As each installation is completed |
Programme, actors and distribution of roles
The organising instrument is the quality control programme, which plans from the start what is controlled, with which tests, at what frequencies and with which acceptance criteria, particularising for the works the demands of the regulations and the design. Its direction belongs to the execution director, whom the LOE entrusts with verifying product reception, ordering tests and controlling execution, as developed in the article on works direction and execution direction.
The material execution of the control falls to the specialised agents the LOE itself recognises: the testing laboratories, providing technical assistance through tests and trials of materials and systems, and the quality control entities, verifying the quality of the design, the materials and the execution. Both operate under responsible declaration and accreditation regimes guaranteeing their competence and independence. In works with ten-year insurance, the technical control body is added, whose audit for the insurer is described in the article on the ten-year insurance.
The usual economic distribution deserves contractual attention: the cost of control is agreed, with formulas ranging from a percentage of the budget borne by the contractor to direct procurement by the developer, and the choice is not neutral, because whoever pays the laboratory conditions its perceived independence. The most protective practice for the developer is to reserve the procurement of the control or, at least, the designation of the laboratories.
The documentation: the control that remains in writing
Each act of control produces its document: delivery notes and conformity declarations from reception, laboratory test reports, execution inspection records, final test minutes. That corpus has two destinations. During the works, it feeds decisions: accept, reject, reinforce control where results warn. At closure, it is integrated into the quality control documentation accompanying the final certificate and ends in the building logbook, where it will be the available evidence the day a warranty is triggered.
The documentary golden rule is traceability: each result linked to its batch, its location in the works and its acceptance decision. A test archive without traceability is a collection of papers; with it, it is the building's verified biography.
Frequent errors
The first is starting the works without a control programme, improvising frequencies and tests when the units are already running. The programme is drafted with the design and contracted before setting out.
The second is trimming control as a savings item: its cost is a minor fraction of the budget and its absence multiplies the price of every defect discovered late. Each defect found late costs a multiple of the test that was skipped.
The third is covering without verifying under schedule pressure, the most expensive individual decision in the catalogue, because it turns routine checks into exploratory demolitions. The check is programmed into the works plan so it does not compete with the schedule.
The fourth is the disordered archive: tests that exist but cannot be found, results without batch or location, and a building logbook arriving incomplete exactly where it was worth most. Tests are filed with their batch and location on the day they arrive.
Note: the concrete control requirements per material and unit are those of the technical regulations applicable to each works; the frequencies and criteria cited must be particularised in each project's control programme.