MEDIA

Use of precast slabs takes months off construction time at Madeira Isles

Elematic SA’s precast hollow core concrete slabs have once again proved their worth when it comes to time-saving and efficiency on a building project. The Benoni-based manufacturer has supplied 30,500m2 of concrete slabs for Madeira Isles - a massive housing project in Danville, Pretoria – and has helped reduce the construction time by six months.

Madeira Isles is a 500-unit development covering a total of 40,700m2 of floor area. It is made up of 14 apartment blocks comprising four floors each. The apartments are divided into 56 three-bedroom units, 388 two-bedroom units and 56 single bedroom units. All units have been developed for the rental market. The project broke ground in November 2013 and is on track for completion at the end of April 2015.

Boutel Projects is the main contractor on the project and has been responsible for the contract as a whole on behalf of the client, ESS. Boutel has been in operation in its current form since 2013, but grew out of a large and well established plastering and tiling firm. By introducing experienced directors, management and staff, Boutel’s founder – Americo Pimentel - positioned the firm to be able to take on medium sized commercial construction projects with a view to building a reputable construction company.

When Boutel was appointed to built Madeira Isles, the original plan was to use traditional concrete slabs for the flooring. “We were concerned about the speed at which the project had to be done,” explains Pimentel. “For us to complete the project in the specified time period, we realised that we had to go the precast route - that was when we contacted ESA to get involved in the project negotiations.”

He adds that the biggest challenge the contractors were going to face on site was that two other trades needed to complete their work first, in order for the precast slabs to work as intended. “There was brickwork to be done and the steel structure had to be completed to support the precast concrete. The biggest challenge with both of these trades was to maintain accurate measurements on each floor and to keep the building square,” Pimentel continues. Because ESA’s slabs are manufactured at its factory off site and are produced to exact tolerances, there was little room for error on site.

Despite these challenges, work progressed as planned and six months of construction time have been shaved off the original expected completion date. “Using ESA’s products gave us substantial time savings, and the quality of the product is excellent,” says Pimentel. This is the second project that Boutel Projects has completed with ESA, and the working relationship has proved mutually fruitful.

Craig Webber, director at ESA, says that his company’s intention right from the outset has been to deliver a top-quality product and service to clients and to develop long-term working relationships. “We are proud to be able to take on a project of this magnitude and deliver benefits for our clients. We look forward to working on more projects with Boutel,” he says.

Elematic SA’s bigger factory meets growing demand

Sustained demand for precast hollow core concrete slabs saw Elematic South Africa (ESA) doubling its output capacity earlier this year, with the construction of a second manufacturing plant. The initial manufacturing facility comprised eight 120m long extruder beds. With the construction of a new factory which was completed early in 2015, another eight were added, bringing the total to 16 extruder beds. 

According to Craig Webber, director at ESA, the expansion was due to high demand for ESA’s products. “Property developers and building contractors have seen the benefits of using precast concrete floor slabs over the years and demand has been surging,” he says. “The product is becoming more widely used as it is well known to save time and money during the construction process. On top of that, we have always aimed to provide a good and reliable service to our customers.” This has not only secured the company word of mouth business, but many repeat clients as well. 

ESA has been manufacturing precast hollow-core concrete slabs at its manufacturing plant on Gauteng’s East Rand since 2007, using internationally respected precast technology. “The extrusion methods we use are well known in the industry to produce the best quality hollow core slabs,” Webber adds. Elematic itself is a well established international brand. It was established in Finland in 1959 and currently has a presence in over 100 countries on six continents worldwide. Added to this is the fact that Elematic South Africa’s production facility is ISO 9001 certified and all its products carry the SABS mark of quality. 

It is a testament to ESA’s high quality products and superior service that the company has continued to grow despite difficult economic circumstances. Recession struck South Africa just a year after the company started operating. Nevertheless, it has managed to grow its market share steadily, with demand being at an all-time high when the second factory opened. “Our intention from the outset was always to grow the market and we certainly believe we’ve done that. It is always healthy to have competition in the market,” Webber comments. 

ESA supplies hollow core concrete slabs to customers throughout South Africa and beyond its borders. Slabs are available in thicknesses of 120mm, 150mm, 200mm and 250mm. In order to ensure that the production line experiences minimal delays, it is important to have as reliable a supply of raw materials as possible. To ensure a long term reliable supply of aggregate, Elematic’s holding company acquired Atoll Mining, a dolomite quarry situated about 500 metres from the company’s main factory.
Apart from ensuring a reliable aggregate supply, additional benefits are the high quality and consistency of the aggregates supplied by Atoll. “The quality of the ‘classified sand’ produced by Atoll using air separation technology from the USA is of particular importance for Elematic in the manufacturing process. The classified sand has a very defined and controlled ‘cut point’ due to the sand being classified in a dry process. The use of this dry classified sand dramatically reduces the water demand in the batching plant and produces a very constant high strength concrete,” explains Webber. 

Hollow core concrete slabs continue to grow in popularity as construction timelines are pressurised and contractors require reliable solutions. Customers can be assured that all ESA’s products are manufactured in a controlled environment, to the highest standards and finishes. The products also have a degree of environmental friendliness – their acoustic and thermal properties are better than those of a solid slab, and conform to the new, more stringent requirements in the building regulations for these properties. The slabs can also be recycled. 

ESA has built up a solid reputation and a large customer base over the years. The company has a long track record of successfully completed projects, some of the most prestigious of which include the Gautrain Station parkade at Rosebank, the parkade for the new registration hall at the UNISA campus in Pretoria, and the 50,000m2 Stella Park shopping centre in the south of Johannesburg. 

Poor soil conditions and tricky site no problem for ESA’s slabs

A combination of difficult soil conditions and an environmentally sensitive site have presented tricky challenges for the design and construction team working on Country Life Estate – a new retirement estate currently under construction in Benoni, Gauteng. The use of hollow core precast concrete slabs manufactured by Elematic South Africa (ESA) has made a difference in both respects.

Initial geotechnical surveys did not reveal the high water table and challenging soil conditions on site. It was only after taking occupation of the site to begin work that the construction team discovered that straightforward strip foundations and cast-in-situ floor slabs would not be an option. A new engineer was quickly appointed on the job and the design revised – this time to include piled foundations and suspended ground beams for all 300 free-standing units and the service centre with its 200 apartments and frail care unit.

ESA, which specialises in manufacturing precast hollow-core concrete slabs, is supplying a substantial quantity of the slabs which are being used to construct the suspended ground floor slabs in all structures and almost all of the suspended slabs in the service centre. The slabs, which are manufactured at ESA’s newly-expanded factory not far from the site, are able to be delivered and installed quickly and easily - saving the construction team time which would normally be required for curing in a cast-in-situ scenario.

Driks van der Westhuizen, construction managing consultant for Central Developments (which is developing and building Country Life Estate), says that the discovery of the difficult soil conditions threatened to derail the construction programme and dramatically increase costs. Having worked with ESA on previous projects, he knew that the quality of the slabs, the speed of delivery and installation and the ease of communication with ESA’s team would all ease the process.

In addition to these benefits, using a product that is manufactured off site has had further importance with regard to easing some of the difficulties associated with working on an ecologically sensitive site. Approximately half of the 26ha site consists of a wetland. The Department of Environmental Affairs has strict regulations aimed at minimising the impact of construction activities on the site. Benoni is known to be home to some unique fauna and flora – a site just a few kilometres down the road is one of only three known breeding sites for the African bullfrog.“

We are keeping large, heavy vehicles off the site (resulting in a lot of double handling of materials) and limiting the mixing of concrete and mortar, which may not be mixed on the soil,” explains Van der Westhuizen. In this respect, using ESA’s slabs has also been beneficial since the products arrive on site ready to be installed with the minimum of complications.

ESA doubled its manufacturing capacity with a massive expansion at its ISO certified factory. “This expanded capacity has meant that we have been able to meet Central Developments’ demand on site without complications and delays,” says ESA’s director, Craig Webber. He is pleased that ESA’s slabs are helping his client to keep construction on track, and that they provided a simple solution for helping to meet the environmental requirements, too.

Construction is progressing well, with Phase One having opened on 1 July 2015 and the remainder of the construction phases looking to be ready on or close to the original completion dates.

Innovative facade created with hollow core concrete slabs

Precast hollow core concrete slabs are not just ideal as a reliable and time-saving solution for building floor slabs, as a recent project shows. Slabs manufactured by Elematic South Africa (ESA) have been used in an innovative fashion to create a striking façade on The Odyssey, an upmarket apartment building in Morningside, Sandton.

Although the slabs supplied by ESA have also been used for all the suspended floor slabs on the approximately 3 000 square metre project, they have also been applied on the balcony cantilevers. In creating a visually interesting three-dimensional form, the slabs were used in a rather unconventional but very effective way. The result is a play of rectilinear elements in different planes.

Creating this same effect with the alternative method – cast-in-situ concrete – would have been considerably more complicated and time consuming. Carl Eckert, a partner at Messaris Wapenaar Cole Architects (the firm responsible for the design) explains that even though there were some challenges associated with ensuring that every element worked together structurally as well as visually, ESA’s in-house engineer and design team worked tirelessly with them to develop the most appropriate solution. ESA’s director, Craig Webber, was also regularly on hand to address any queries.

The project is being developed by Renprop – a well known residential property developer, and built by Delmar Construction. Conrad Swart from Delmar Construction comments that the company has worked with ESA since 2006, and has experienced consistently good service, delivery and product quality from the hollow core slab manufacturer – so much so that it now works almost exclusively with ESA. The Odyssey is yet another in the long list of projects completed together.The smooth collaboration between the various members of the professional and contracting teams has proven that unexpected and innovative solutions can be achieved when all parties commit to working collaboratively.

The resulting building is a striking, modern, luxury apartment complex which will be an asset to its neighbourhood. Located almost opposite Morningside Shopping Centre on Rivonia Road, it has a prime address, its first phase is now complete and the second phase is due to commence shortly. Phase One consists of 29 units, which range from approximately 100 square metres in size for a standard unit to over 300 square metres for a luxury penthouse unit. Phase Two will see the construction of a further 32 units.

Flexibility and value engineering combine with high quality products

Elematic South Africa’s high quality precast hollow core concrete slabs and top notch service on the Carlswald Luxury Apartments development in Midrand secured the company a good pipeline of work from the estate’s developer, Century Property Developments, going forward.

The Carlswald Luxury Apartments project was no small undertaking. The 470 units, configured in 86 blocks, were developed and built in a single phase by Century Property Developments between May 2015 and October 2016. The development also includes a variety of amenities such as a multi-purpose hall, club house, swimming pool, braai facilities, tennis court with pavilion, children’s play areas, outdoor gyms, a skate park, a bird hide and a Spark School for the children of residents.

Elematic South Africa (ESA) supplied all the precast hollow core concrete slabs for the project, supplying about 55,000m2 in total. Hendry Brand of Century Property Developments explains that precast hollow core slabs were selected primarily because of the speed they offer in comparison to cast-in-situ concrete slabs. Overall, the construction team was able to complete approximately 40 units a month on average – an achievement which would not have been possible without careful planning, co-ordination and team work.

In that respect, Brand is highly complimentary about the service Century Property Development received from ESA. “To begin with, there were a number of different designs that had to be catered for because of the various different apartment and block configurations. We used all the different thicknesses of concrete slabs available – sometimes we even used them all on a single floor,” he notes. He goes on to say that even before the project broke ground, the Century Property Developments team, including its in-house architects, sat with the ESA team to look at ways of optimising the structures for economies of scale, and to value engineer for cost-effectiveness.  “We worked well together because we both like precision, and we like to have things well planned out in advance,” he comments.

There was an ESA team on site almost constantly for the duration of the project, measuring up and installing the slabs, which were on the critical path for project completion. Brand reports that Century Property Developments has been very pleased with both the quality of the slabs and the service received from ESA. “In terms of price, quality, service and our working relationship, we really do get the whole package from ESA,” he says.“

We need a high quality product because we want longevity in our buildings, especially since they are for the rental market. At the same time, we also need to find ways of optimising our costs, which can escalate quickly on a project of this size,” he continues. ESA’s willingness to explore options with the client, whilst maintaining high attention to detail and not compromising on product quality, helped ensure the successful delivery of Carlswald Luxury Apartments.“

We make every effort to explore options and to value engineer each project with our clients,” notes Craig Webber, director at ESA. “We also try to improve continually on what we have done before.”

This meeting of minds has resulted in a good working relationship with Century Property Developments, which has awarded ESA a number of other contracts subsequent to this one. “There are benefits to working with the same contractors and suppliers if we can,” comments Brand. “The ESA team know what questions to ask, they know how we work and they are extremely thorough. Like us, they take pride in their work. We also find that working with people we know means we don’t have to go through a process of trial and error with a new contractor for every project, because that can result in costly mistakes,” he adds.

The Carlswald Luxury Apartments development has certainly been a success, with only a few units left to let at the time of writing. With one-, two- and three-bedroom apartments available, ranging from 53m2 to 113m2, these luxury rental units in a secure lifestyle estate have become extremely popular. The project also saw the development of a good working relationship between Century Property Developments and ESA. With a number of new projects in the pipeline, both parties look forward to a mutually beneficial relationship in future.

Precast slabs from Elematic ideal for social housing

Delivering social housing projects for the public sector is different from delivering private sector projects, as deadlines are driven by political imperatives rather than programming. Construction products which can be installed quickly and accurately, like precast hollow core concrete floor slabs from Elematic South Africa (ESA), therefore make a great deal of sense when it comes to meeting those looming deadlines.

ESA is currently supplying some 10 000m2 of hollow core concrete slabs to City Deep Green, a social housing project that is currently underway in City Deep, Johannesburg. City Deep Green is being developed by the Johannesburg Social Housing Company, Joshco, and is one of several similar projects that are underway at the moment.

As Gauteng continues to expand and people come to the province in search of jobs, the need for decent accommodation keeps increasing. Many old hostels in and around the city have been converted into social housing to provide accommodation for families coming from other areas, but the shortage has still been dire. The City Deep area in particular has always been a central node for labour and there continues to be a shortage of housing there. As a result, Joshco has been developing properties owned by the City of Johannesburg in the area to create additional rental housing stock. Families earning less than a stipulated income per household then qualify for a subsidy to rent these homes, which will not be sold and will remain the property of Joshco as rental properties.

The Motheo Construction Group – an established BEE construction company, which generates some 90% of its turnover from government work - is the main contractor at City Deep Green. Completion of 328 units is set for May 2015. The project, which is situated on Greatermans Street in City Deep, has been constructed in phases as funding has become available from various donors. The current phase requires the delivery of 220 housing units by June 2014.

Units are being constructed in four storey, walk-up blocks and will be one and two-bedroom homes with basic finishes. Highly engineered raft foundations have been used because of the specific ground conditions on site. These have been followed by structural brickwork and then precast Elematic slabs on three levels. Finally, the structures will be topped by IBR roof sheeting.

John Whiteman of Motheo Construction Group explains that the project engineer specified precast hollow core concrete slabs as they are faster to erect than the traditional cast in-situ concrete floor slabs. “ESA was appointed on its known ability and its price. Quality and efficiency of erection are the deciding factors on a job such as this,” he says. He adds that the accuracy of the slabs and the finish are always good, saying that the slab soffits are neat and the v-joints fit together without gaps, resulting in a good quality, aesthetically pleasing finish.

ESA and Motheo have worked together on several projects before, and are also currently working together on another Joshco project in Soweto, so reliability and an open working relationship have been key to doing business.

ESA manufactures its hollow core concrete slabs at its ISO 9001 accredited facility on the East Rand. “Our in-house engineers ensure that the product specifications meet the correct requirements for each project and the slabs are manufactured accordingly. Dedicated installation teams transport the slabs to site and install them. Our SABS certification assures clients of the quality of our products,” says Craig Webber, director at ESA.Although labour complications, rain and year-end pressure at the end of 2013 combined to put a great deal of pressure on the team, the Motheo Construction Group and ESA agree that they have worked well to overcome these challenges as a team and to keep the project on track.