Bamboo Structural Systems : Post And Beam
Post and beam construction is a common structural system used in many conventional and traditional buildings. Traditional post and beam systems allow for the creation of expansive and flexible interior spaces.
In conventional architecture post and beam structures are built using materials like stone, timber, and RCC. This makes them rigid but restricts building designs to 90 degree framed members.
Because of bamboo’s lightweight and flexible nature, it provides some interesting opportunities and variations on the traditional post and beam construction.
In this article we share the 3 main types of post and beam construction that are used in bamboo architecture:
- Vertical posts and Horizontal beams/ trusses
- Fan/ Spray posts and Curvilinear beams
- Central Tower posts and Ring beams
1. Vertical Posts and Horizontal Beams/ Trusses
Inspired by traditional timber framing, vertical posts and horizontal beam construction follows the same principles as those used to build traditional wooden houses. The structure is supported by three main elements: vertical posts, horizontal beams, and cross-bracings to triangulate the structure for stability. In bamboo architecture round bamboo poles are used for the structural elements. The roof structure is then supported with trusses.
The Green School classroom pictured below which was built during a Bamboo U Immersion in Bali is one example of this system.
This structure is a 14M long and 6M wide G+1 building. Dendrocalamus asper poles were used for all the structural members. This structure is supported by 5 mainframes each consisting of 2 main posts, 2 main beams (also supporting the intermediate floor), and a kingpost truss to support the sloped roofing. 32 cross bracings were added here to support the main structure and 8 diagonal struts to support the roof structure. All the bamboo mainframes were built on the ground using a template system and lifted manually into place with a pulley and ropes, very much inspired by traditional barn raising.
2. Fan / Spray Posts and Curvilinear Beams
This structural technique combines round bamboo poles and processed bamboo elements to create curvilinear, organic-shaped roof structures. In this system the structure is supported by three main elements: inclined posts, curvilinear beams, and cross-bracings to triangulate the structure for stability. Round bamboo poles are used as posts, processed bamboo (splits, lidi, and/or rup rup ) are used as beams, and depending on the design of the building the material used for cross bracing varies. This system is a signature of IBUKU’s designs.
Below you can see pictures of different typologies of fan or spray post and curvilinear beams from Sharma springs, Green village (left) and Green Camp’s activity space (right).
Sai joined the Bamboo U team in March 2020 as Research & Development Manager. He is also a natural builder and an architect from India. He has managed many mud and bamboo projects over the years.
August 19th, 2022
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