Due to ease of assembly, the aluminium formwork allows a four to seven days cycle, which is much lower when compared to the 14 to 30 days cycle for the conventional timber method
Njange Maina @NjangeWaEunice
Real Estate Company Homex, last month built a three-bedroom house in Nyeri county in a record 10 days.
Arguably, 10 days is the shortest known time in Kenya for building a modern, three-bedroom house. For the Nyeri house, the architectural plan was first drawn before an aluminum formwork was mounted and filled with fast-curing concrete.
Once the main structure was in place, what remained was only roofing and dismounting the formworks. By the sixth day, over 70 per cent of construction works had been completed and furnishing ready to set in.
On the 11th day, Machakos governor Alfred Mutua handed the keys of a fully furnished three-bedroom modern house to the owners. The governor had earlier promised to build a modern house to an elderly couple in Nyeri.
The record construction time was made possible thanks to Kumkang Kind, a South Korean-based aluminium formwork company. The firm has been making inroads in Africa, especially Algeria and Kenya.
Formwork is a timber or metal mould, which holds raw concrete for pillars, lintel or slab during construction. Kumkang uses concrete entirely for the foundation, walls and slab. The firm uses metal technology whose formwork can build over 300 times.
Sam Muihia, the business development manager for Kumkang Kind Kenya, says the company saw an opportunity in East Africa and decided to give it a try. “Kenya’s construction industry is doing well and we saw it as an ideal centre for the regional market,” says Muihia.
After the recent ban on logging, which made timber products prices to skyrocket, metal formwork seems a better alternative and may pick up. The formwork is made of aluminium 6061 alloys that are hard enough to resist basic mechanical stress during routine construction and handling process.
Due to its low density, aluminium is a also much lighter than steel and id is hand-lifted as opposed to using a tower crane. Construction begins by assembling the aluminium formwork at a construction site.
Muihia says that prior to assembling the structure, oil is applied on the surfaces of the formwork to prevent the concrete from sticking to the planes of aluminium panels. Different bars are used for different sections of the site.
Normally, assembling the panels takes one day. For a multi-storey building, an entire floor is cast in a single pour of concrete. After the Formwork is assembled up to the slab level, fast curing concrete is poured into the mould. Once the concrete has dried, the formwork is dismounted and prepared for the next building — or the next floor.
The same formwork can be used to build over one building at an alternating sequence hence, allowing timely completion. Due to ease of assembly, the aluminium formwork allows a four-to-seven days cycle, which is much lower, compared to the 14 to 30 days cycle for the conventional timber method.
“After dismantling the panel, the frames leave a smooth surface that does not require plastering, reducing finishing costs,” says Muihia. The assembling of the panels doesn’t require specialised skills hence lowering cost of labour.
“Anyone who can understand an architectural drawing can assemble the formwork. We also train skilled and unskilled labourers to mould and dismantle the aluminum bars,” says Muihia.
For cost effectiveness, Muihia says a housing project has to have over 50 units to cover initial costs and earn some profits. This means the the formwork used by Homex to construct the Nyeri home project was used to repeatedly build several similar homes all over Kenya, reducing the cost of construction and most importantly the cost to the end user.
Kumkang was established in South Korea in 1978 and listed on the Korean stock exchange in 1989. In 2003 the company was awarded ISO 9001 certification. So far, it has earned over $1 billion (Sh100 billion) in exports.
To establish and start operations in Kenya, Kumkang had to get certification after passing all the safety tests. So far, Kumkang has completed over six local projects among them Kabete Palms (Lower Kabete) and Kitisuru Gardens.
However, establishing in Kenya has not all been a bed of roses for Kumkang. Muihia says that overreliance on retrogressive building technology (such as brick and mortar) has limited the construction sector from accepting new technologies. “The greatest task for now is creating an awareness; for instance, many people continue to use timber in formwork,” adds Muihia.
The local construction sector is also flooded with cheap imports mainly from China, most of which are counterfeits. Additionally, the perception among some Kenyans is that Chinese building accessories and fitting are fake “Some initially find it hard to distinguish between Korean and Chinese products,” Muihia laments.