The mystery of the missing rebar

index12Gem Engserv provides services of preparation of BBS, rebar shop drawings and rebar estimation. We often get some interesting and challenging assignments. The challenges include complicated structures, frequent changes in the designs, incomplete information on the drawings and extremely tight delivery schedules. All that is part of the business and we are ready to meet these challenges.

A few months ago, we were approached by a Contractor who posed a different kind of challenge. The Contractor was close to completing construction of RCC portion of a group of high rise towers. We don’t know what triggered it, but the project team suddenly realised that more than a few hundred metric tonnes of rebar were missing from their books. The quantity of rebar billed to the Owner and the quantity available in stock & scrap did not tally with the quantity received by them from the owner. Since the quantity of the missing rebar was significant and the final bill for the work was to be raised soon, the alarm caused by the potential loss was accentuated by urgency of finding the missing rebar.

The Contractor must have investigated and eliminated the possibility of any fraud before approaching us, and must have realised that the missing rebar was likely due to incorrect billing! The quantity of missing rebar shocked us as much as it must have surprised them. The task assigned to us was to independently re-construct the BBS, compare it with their on-account bills and get the difference approved by the client.

To our and  the Contractor’s satisfaction we succeeded in the assignment and helped the Contractor retrieve a large portion of the so called ‘missing rebar’, which was actually not missing but was consumed in construction yet not billed!

To our surprise, this was not a one off case, and over the next few months, we carried out similar assignments for a few more Contractors. In addition, we missed doing some assignments for a few other potential customers who found other resources to carry out similar exercise.

This made us ponder over the state of affair prevailing in the industry with regard to rebar billing. In the course of our interaction with our clients, we realized that the job of preparing the bills / BBS is typically entrusted to a site Engineer [sometimes designated as BBS Engineer]. Such an arrangement suffers from the following disadvantages:

  • The site Engineers are not trained in rebar detailing, which has an impact on the correctness and accuracy of the BBS. An accurate BBS requires study of GFC drawings, pour sequence, code of detailing, technical specifications and commercial conditions of the contract. Engineers are generally not trained to have a holistic appreciation of all these aspects.
  • The quantum of work is too high for one or two BBS engineers to handle. This causes errors and omissions. Changes in BBS engineer, due to transfers and resignation, compounds the problem.
  • The Engineers
  • who review and approve the BBS do not have any incentive to point out if the BBS claims lesser quantity than what the contractor is legitimately entitled to.
  • There is great pressure on the Engineer to prepare the BBS since the progress of work and cash flow (billing) depends on his output.
  • Unless there a strong inventory control and periodic reconciliation of rebar is taken up, gap in the rebar quantity is not detected unless it assumes a large proportion of the rebar quantity.

We are sure that many readers would have come across similar situations in their career. To prevent occurrence of such problems, we suggest the following preventive actions:

  • The job of preparation of BBS should be entrusted to Engineers who are trained for it. There are many specialist agencies like us who provide this service.
  • All field Engineers should be trained in the basic principles of rebar detailing and rebar management. This is required not only from commercial considerations of accurate billing, but also to ensure that the design intent is correctly translated in the RCC construction.
  • Preparation of BBS should be done in advance of the pours except in emergencies. This will allow for a thorough review and provide opportunity for clash detection and optimization.
  • Certification of BBS from client prior to concreting will resolve many problems like wastage of rebar due to wrong detailing, omissions etc. thus resulting in better control of rebar consumption.
  • There should be a centralised rebar yard [even if there are multiple bar bending sub-contractors] and all BBS should be combined to carry out rebar optimization.
  • Serious thought should be given to use of pre ‘cut and bent’ rebar.
  • Timely reconciliation of rebar should be carried out including checking rebar inventory and rebar in WIP.

These efforts are sure to take the mystery out of missing rebar!

Shashank Vaidya


GEM Engserv Pvt. Ltd.