Mario Kleff sets a new standard for Thailand with the longest cellular beam currently used in residential construction

Construction News

Mario Kleff sets a new standard for Thailand with the longest cellular beam currently used in residential construction

Successfully installed a 48.00 meter long cellular beam between the columns to support a tensioned high strength concrete slab 0.35 meter thick, on a housing project in Pattaya

Majestic Residence on Phra Tamnak Hill in Pattaya hit the headlines over the summer of 2021 when architect Mario Kleff demolished two villas and started building a new one, utilising the finest in German engineering.


The construction company Wandeegroup Asia, under the direction of CEO Mario Kleff, began work in June of this year. The Substructure work, consisting of 100+ piles and large concrete foundations were laid first, allowing the new villa to be safely and firmly set on the rock. 100 tons of steel and 700 m3 of high-strength concrete mix were used for the construction work on the foundation, swimming pool and basement.

What followed would impress some of the world’s greatest engineers, as large steel girders were prepared for the two upper floors, sitting on a 48-meter-long steel girder – 48 meters is the distance between the two pillars, representing the width of the property. On top of it is a heavily post-tensioned concrete slab with a thickness of over 35 cm.

In residential buildings, like villas and bungalows, steel girders or steel beams with a length of 6 to 12 meters are commonly used. Girders over 20 meters are rarely found even in heavy structures, such as car parks or public buildings. So for this local project to include an almost 50-metre long steel girder, it speaks wonders for the future of villa construction and engineering in Thailand.

We spoke to Mr Kleff about the project, and he had this to say, “Apart from the fact that the Wandeegroup is constantly pushing the boundaries in Thailand construction, the wide and column-free windows that this villa possesses really is a unique engineering feat for Thailand.


“There are various ways of creating column-free spaces, but the integration of wide-span cellular beams and post-tensioned concrete slabs were the most suitable for this project. However, 48 meters from column to column is unprecedented in Pattaya.

“We have structures built outside of Thailand with spans of over 30 meters and have designed buildings with spans of 40 meters, but 48 meters is the first structure under construction.”

When The Thaiger started reporting on this project in Pattaya, no one would have expected such a design. Now it becomes clear why Mario Kleff is to become a registered trademark for architectural design in Thailand and beyond.

Buildings with such an approach can be categorised as architectural art. We’ll be sure to follow up on this project and report the final


Information we received from Mario Kleff:

The villa is approx. 2,500 m2 of usable space, 550 m2 of which is in the basement. It consists of both high-strength steel mixes for beams and ultra-high-strength concrete mixes for columns and slabs. Such concrete is used in modern bridges and high-rise constructions.

The villa was designed by the architect Mario Kleff and his assistant architect Waraporn Na-Lampang, including civil engineering and structural engineering. Since Mario is not a licensed architect in Thailand, leading engineers like Dr. Songkiat Matupayont, Prapat Boonlualoah and Sadudee Boonlualoah joined the project to review the design and agree on the construction process.

Mario Kleff and Dr. Songkiat Matupayont, the managing director of CASE Co., Ltd., worked together on other projects with wide-span cellular beams and wide span concrete structures since 2008. Songkiat is a specialist in steel and concrete. Span Systems International LTD under the direction of Prapat and Sadudee Boonlualoah delivered a tensioning solution to span the floor slabs up to 48.00 meters sitting on just one steel girder. The combination of post-tensioned concrete and cellular beam was introduced to Thailand on Park Royal 2, a development of Heights Holdings.

When completed, this villa will set a new standard in residential construction in Thailand. Mario Kleff, Managing Director of Wandeegroup Asia Co., Ltd., who focused on high quality structures, has made headlines in the design and construction sector with extreme designs for villas and residential towers in the Chonburi region for the past 15 years. The company is known for pushing the boundaries of civil engineering.

In addition to an outstanding technical solution, this project is characterized by large and wide window panes and an enormous overhang on the upper floor. A free-hanging slab is poured about 20 meters on each side from the center of the structure. Mario designed large steel box girders to support the roof plate. Such a design can be found, for example, on a highway bridge in Bangkok. The construction technique to support the lower ceiling panels is the first to be built in Thailand.