Pasos en el desarrollo del análisis

Work should be inspected, before, during and after the activity. At the interface of building and services work this means:

• confirming a work area is suitable for BS to commence;

• the BS contractor inspecting the work during the activity and

• confirming to the builder that the work is complete and

• commencing another defined activity in the same area or

• releasing the area back to the builder for following trades;

• the work of trades as they follow that left by the BS contractor should be inspected to confirm the achievement of the interface, without damage.

The site manager should arrange spot check inspections of the first piece of work that is carried out by each new BS trade that is commenced on site. This has a twofold benefit; it notifies the BS contractor that you are serious about inspections and should ensure the achievement of specified standards from the beginning. We all know how much easier it is to lower a high standard than it is to raise a standard that is unacceptably low.

The initial spot check should start as the material arrives on site:

• Is the drainage material as spec?

• Is the sheet metal ducting of the right gauge?

• Is the steel piping the correct weight (medium or heavy), mild steel or galvanized?

• Is the cable on the drum the same as the drum markings?

That’s got the general M & E underway but it is just as important when

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the new specialists and subtraders arrive later in the job, to carry out the same check on the first activities of their work.

The site manager should arrange inspection for the access routes to be clear for the delivery of plant and equipment into the building. It is not uncommon for plant to arrive and find that access which was clear 24 hours earlier is now blocked by sand, ballast, a water barrel and concrete mixer. Do not release an area then through the activity of building work render the space unusable. Having reached agreement with the BS contractor that riser shafts are available for the installation of distribution systems you will hear soon enough if the temporary brick edgings at upper level have been removed and the shafts are being used as refuse shutes. It is your project and you, the site manager, should be inspecting that the BS contractor is working to his method statements’

safe working arrangements and not being put at risk by the unsafe practices of others.

Returning to the subject of interface inspections and in order to avoid conflict, arrange for inspections to take place as one contractor vacates a work area and is followed in by another. Certainly BS contractors have damaged the work of others; but in return they have suffered greatly. Under many subcontracts they are responsible for the protection of their works in areas that they are not working in, and the nature of their work makes it unprotectable, e.g. all the services above the false ceiling in an air conditioned, sprinkler protected office building are at risk as ceiling contractors fix primary and secondary grids. In turn, the ceiling contractor’s work becomes at risk as wiring is pulled through and final connections made from AC terminals to grilles and pre-wired light fittings plugged in. By making worthwhile inspections at these interfaces the site manager can aid the development of a ‘caring site’ culture.

7.4.8 DEFECTS

In an imperfect world defects will arise from a lack of understanding of what is required and a shortfall in inspection by the person doing the work. As that person moves along on the same piece of work or commences a new activity believing it to be compliant with requirements, he enters the domain of the inspector. But didn’t we define inspection as an examination that could also take place during an activity? We did, but during an activity the supervisor may issue a verbal instruction instigating immediate corrective action in order to avoid a recordable defect being noticed by others. This is a not uncommon cycle of combined supervision and inspection at the workface by the workforce’s management. It results in unrecorded rework by the BS contractor which the PC has difficulty in spotting

unless it is obvious, e.g. prefabricated boiler header pipework being observed in position one day and a few days later being ‘nowhere on site’, having being returned to the prefab shop. Observations of current incorrect construction may be recorded by the DT clerk-of-works and notified to the site manager. From this example we can see the importance of the site manager agreeing with the BS contractor that all defects are to be recorded whether they arise from inspections during or after completion of activities. Both parties must come to an agreement as to how work is to be inspected, defects recorded and cleared.

The site manager should ask for copies of all the BS contractor’s own recorded defects and reinspection or ‘defect cleared’ sheets and logs.

This information will repay valuable study from which the site manager must judge:

• Are the defects considered to be excessive?

• How long after the raising of a defect does it take for the clearance sheet to come through?

• Despite the defects and rework is the BS contractor still on programme?

If the answer to the last question is no, it raises questions about the impact on the following trades and risk of damage attendant upon the BS rework. Answers to these questions and his own views repay study time put in by the site manager and empower him to act. All of this valuable knowledge has come about by the site manager making sure he armed himself with the results of the BS contractor’s own inspections. It is those inspections that should be the most expert and regular. Possibly, and some may say not unreasonably, the BS contractor may be reluctant to provide details of his inspections because he has not carried out enough and/or the general level of workmanship is not up to standard.

In these situations the site manager becomes involved in an extractive process that is nevertheless worth pursuing. Now is the time for the site manager to look for leverage within the BS contractor’s QP and any agreements made with him for his QMS to be audited by the PC. The route to information on a reluctant BS contractor’s defect management status is through a reminder of the promises made through his QP, approved method statement and any right established by the PC to audit them. BS contractors may have ulterior motives and cut back on inspection hoping that others will tell them if their installation work is not up to standard. Although the PC may only be left with the DT/clerk-of-works and his own inspections of the BS contractor’s first work on site and at the interfaces with other trades mentioned earlier, he should avoid increasing his level of inspections. As a last resort where a BS contractor defaults on verifying compliant work in voids, then the PC may wish to notify the contractor that ‘arrangements will be made to

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have the work in voids verified before closure, the costs of which will be to BS contractor’s account’. Regrettably, we are deep into conflict of which difficulty over establishing compliant work may be but another manifestation of a poorly performing contractor. Every PC with a QMS will have a standard sheet for advising of a non-conformance. This sheet may be used for other purposes. Intended primarily for use in notifying work not complying with specified requirements it can also be used in association with BWIC and temporary works, e.g. electrics etc.

To maintain the benefits of a recognizable format the non-comformancies identified by the DT/clerk-of-works or any of the external inspectorate parties could be attached to this sheet.

The great emphasis of this section on inspection has been on compliance with specified requirements; but what about progress to time?

References

[1] Harding, Colin (1994) Time for architects to relinquish their leadership, Building, 11 February.

[2] Torrance, Jack (1987) The building site minefield’ Building services, February.

[3] NALM (1994) Principles of Planning and Programming a Lift Installation, with relevance to Escalators, London.

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