Using Dry-Cementized Construction and Re-Use Techniques For Mass Building Construction To Save Cost and Time -Osaz' ENOBAKHARE

Dry-Cementized construction and Re-use Techniques
can be used to save cost on large projects

A term of contract for a project may require a contractor to construct a large number of buildings (say 50-100 units) within a short period of time (e.g. 2-3 months). Often than not in such cases even when the conditions are well spelt out, most local contractors readily accept the job without necessarily designing a workable blue-print on how to complete the project within the stipulated period of time, hence few days to the expiration of the deadline, they are still staggering at 30-40% completion.

Project planning is very crucial to the successful delivery of any project but planning a project in isolation of the technique to carry out the actual work itself is effort in futility because it is the work on ground that matters more than the print on paper or soft notes.

For construction projects where pre-fab or pro-fab construction techniques are considered expensive, a smart combination of dry-cementized construction and re-use method could be adopted. 

Most buildings in this part of the world are made from brick and concrete hence a good case for the use of dry-cementized construction. In using this method, the volume or type of cement used in the mix for the concrete elements and components within the structure are increased so that they dry or harden very quickly such as will enable the speedy removal of the formwork. For instance a structural design specification of a minimum concrete mix of 1:2:4 (i.e. 1 part of cement to 2 parts of fine aggregates or sharp sand and 4 parts of coarse aggregates or granite) can be constructed at 1:1½:3 (i.e. 1 part of cement to 1½ parts of fine aggregates to 3 parts of coarse aggregates) which is a more stiffer mix. The idea is to increase the cement content in the mix par aggregates so as to dry quickly while still maintaining the required strength. Alternatively rather than use ordinary Portland cement which is the most common and readily available, rapid hardening cement could be used as a suitable alternative while the original mix is maintained.

 Where the common timber/wooden formwork is to be used, the inner surfaces of the timber is lined with water-proof material (e.g. polythene covering) that does not react with the concrete so as to reduce the rotting of the wood; making it suitable for re-use. Practically, a good wood can be re-used for up to 10 times or for 10 buildings. The carpenter fabricates the formwork in such a way that it can be removed and transferred with ease.  This way the cost of extra volumes of cement used will be compensated by the re-use of the timber formwork.

It is very important to note that when adopting this method, a controlled proportion of water is used; a little less than the usual volumes. In the end, the concrete will set faster and the formwork is ready for detaching in about 24 hours for non-suspended elements (e.g. columns) and about 7 days for suspended elements (e.g. upper floors) – saving roughly 48 hours and 14 days for non-suspended and suspended elements respectively.  

How Instant Messaging and Mobile Banking Help Save Project Cost and Time - Osaz' Enobakhare

Seamless money transfers and instant messaging
promotes construction speed

Finance is an integral part of any construction project so is communication. In fact there would be no construction project in the first place if money and people are not involved. Therefore smooth, constant and healthy interaction between all stakeholders in a project is very important as well as prompt and adequate disbursement/distribution of project funds to areas needed. Advancement in technology has made communication and payments a lot easier yet many local contractors have not keyed into it.

In the past, communication on site was done basically through public address systems, phone calls and SMS which are pretty expensive up to the extent that the walkie-talkie became a highly-cherished engineer’s work tool; artisans who normally couldn’t afford them had to rely on second-hand instructions or information or often had to move out of their work stations in order to gain access to a telephone to pull a call through to their supervisors especially on large sites. 

But today the story is different; with instant messengers like Whatsapp, Viber, Wechat, Yahoo, etc on simple smart phones and tabs everyone on site can communicate seamlessly at very low cost. 

By ensuring that having an instant messenger on your mobile phone is a pre-requisite for site employment, a project manager can save up to 70% of the total cost of communication through e-messengers.

Flexible payments to suppliers and workers through mobile/internet banking channels are in vogue now. Modern day contractors/supervisors now make payments for supplies through their phones or tablets and the receipt of payment is transmitted through the same medium. For instance, using an instant messenger like Whatsapp, once a nominated supplier has delivered the required materials to site, he or she simply sends a multimedia message (i.e. texts plus images) of the materials on delivery via Whatsapp notifying the contractor of the supply. In a split second the contractor receives it on his mobile device wherever he or she is at the time and replies promptly. 

On the same device, he or she opens his mobile banking app and transfers the money for the item directly to the bank account of the supplier. Immediately the transfer is completed, he receives a confirmation SMS from his or her bank and a response from the supplier via the same medium. The supplier then prepares an original e-receipt of payment or alternatively fills out the paper-type manually (crossing out the customer’s signature column/space indicating that the customer is not available to append a signature), scans it or snaps it with the phone and forwards it to the contractor. 

The receipt can be stored immediately in an e-file on the mobile device or printed out and stored manually. In practice, all these processes takes less than 30 minutes depending on the network’s data signal strength; only a few Megabyte of data is consumed and some hundreds of Naira is deducted for the bank transaction for an inter-bank transfer; a transaction that would normally take hours and sometimes days in time past.

It is now safer to conduct business within the e-environment. Traditional methods of issuing cheques or paying cash are increasingly risky, time-wasting and make accounting laborious. In more organized sites, all site workers get their wages as at when due directly in their bank accounts through mobile banking and a pay slip is automatically generated and sent to them via instant messengers. All requests, complaints or issues related to the payment by any worker is transmitted via the same medium at once and the employer can respond promptly. This process completely wipes out the usual queues at cash offices and discourages manipulations and site robbery/theft.

The system is very flexible and makes project funds much easier to organize, distribute and track or trace. Project accounting becomes a lot easier for SMEs, MSMEs and Large scale organizations because if all payments throughout the life cycle of a project was made through a particular medium, accounting data can be extracted directly from the transaction history automatically generated by the app and subsequently transferred to the balance sheet. Discrepancies and misappropriations can be easily detected since each transaction details containing relevant information like transaction volume, date, time, account name and number, and remarks/notes are stored automatically. Using the duo of instant messengers and mobile banking apps in an organized manner saves project delivery time, reduces overhead and logistics costs and increases profit.

Avoiding Re-works and Wastage During Construction -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.