Saturday, 10 December 2016

Avoiding Re-works and Wastage During Construction -Engr. Osaz' Enobakhare

It is not unusual to see re-works on construction sites all over often occasioned by poor interpretation of working drawings, workers not working to engineer’s or builder’s instruction(s) or paying inadequate attention, faulty directives, false construction, site accidents, force majeure, alterations to designs/specifications, malicious or free damage, inconsistent use of materials, poor use of skills, misapplication, mistakes/errors, misappropriation, government/regulator’s actions, mal-handling, etc. 

Generally, re-work is a term used to describe all repeated items of work carried out usually to correct a defect or to allow for an alteration or modification to a section of work during construction. For instance if a block wall in the kitchen area of a residential building under construction was not properly set, any work done to correct the defect observed is referred to as re-work or if the tiles original meant to be installed in the living room was used in the toilet, any attempt to correct the situation is considered a re-work. The re-work itself could involve demolition or some form of breakage, loosening, reconstruction, re-positioning of the affected element or component of the structure, etc.

However for most re-works, there is an almost equal and negative re-cost.

Re-works always arise so they remain an indelible part of the construction process. But the frequency and size of re-works could be reduced to the barest minimum if deliberate efforts are made to forestall them. From common knowledge, wastages and re-works often account for roughly 5% of the entire construction project cost and could be more depending on its magnitude and frequency throughout the project life cycle.  

The cost implications of re-works and wastages resulting from re-works or other construction processes are substantial and significant. If treated with loose gloves, they can affect the project cost and time badly, sometimes leading to abandonment of the project. In extreme cases, re-works may involve demolishing a better part of the structure which may put the contractor at a huge loss.

To avoid re-works and wastage, it is important to;
-          Ensure that all working drawings (I.e. survey plan, site plan, site layout, architectural drawings, structural design/drawings, mechanical/HVAC/plumbing drawings, electrical/lighting drawings, etc), specifications, schedules (i.e. material schedule, plant/equipment schedule, labour schedules, etc.), quantities and estimates for a project are properly studied and reconciled before starting work on site. 

      Any discrepancies observed in the process should be identified and fixed immediately or else such errors may be transferred to the ground. A simple re-design which would have cost close to nothing and can be completed within a short time may later result in a re-work which would eat deep into the project fund and time if left unattended to.

-          The interpretation of the drawings, specifications, timelines etc should be made to all key members of the project team including professionals, suppliers, sub-contractors, fore-men and sometimes gang leaders in such a way that everyone comprehends the nature and extent of the work to be done before commencement of work.

-          There should be effective communication between workers and the project management team throughout the project life cycle. Poor communication corrupt good works.

-          A strong message against deliberate re-works and wastages should be passed across to all site workers and tied to their wages so that they can apply more caution at work.

-          All working drawing should be read together during construction. No one drawing or specification should be read in isolation of the other.

-          Construction permits should be secured on time to avoid preventable actions (demolition) by relevant government agencies. 

-          Only construction materials that meet specifications for the work should be allowed to be offloaded and stored on site. All materials entering the site should be properly checked so as to avoid re-works influenced by the use of sub-standard materials.

-          Unskilled workers (labour) should not be allowed to carry out works meant for skilled workers. Similarly, avoid the use of non-trade tested artisans for works meant for trade-tested persons.

-           Site supervisors should ensure that they keep an eye on activities on site as it progresses from stage to stage and give very clear and specific instructions and directives to the workers at all times. They should also pay attention to details; ensuring that only the right tools and equipments are used for work and only the adequate quantity of materials needed to complete an item of work is provided or released from the store to curb wastages and theft.

-          Site disputes should be managed properly such that it does not degenerate into a situation that can provoke any act of malicious damage to work already done.

With all these and many more, wastage and re-works would be reduced drastically on sites and project cost and time would be saved.

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