“SMart BEAM Floor Framing System” Obtains Technical Evaluation
- First Adopted Property is Constructed in Hokkaido, Japan -

December 8, 2011

  • Tatsumi Corporation
  • Sumitomo Metal Industries, Ltd.

Tatsumi Corporation (Head office in Sanjo-shi, Niigata Prefecture; President - Shinichiro Yamaguchi; Tatsumi), in cooperation with Sumitomo Metal Industries, Ltd. (Head office in Chuoh-ku, Osaka Prefecture; President - Hiroshi Tomono; Sumitomo Metals), obtained a technical evaluation (BCJ technical evaluation-LW0024-01) from the Building Center of Japan*1 for the SMart BEAM floor framing system, a new method that supports the second floor of wooden houses, in July 2011. Construction of the first property to adopt this system has just been completed in Obihiro City, Hokkaido, Japan.

Wooden houses are constructed by using a method where the building is supported by pillars, beams, and diagonal braces. In most cases, laminated lumber (material made of several pieces of lumber bonded together) is used as the beam material. When a joint part of a pillar and a beam is connected by metal, it is called a metal joint. Tatsumi’s “TEC-ONE metal jointⓇ” is long proven and reliable, and has been highly received by customers.

“The SMart BEAM floor framing system” is a method that uses both laminated lumber beam and Sumitomo Metals’ SMart BEAM Ⓡ(SMB), a lightweight welded beam for general structures. It has the following three features.

(1) Its cross-section is strong and this enables a reduction in beam depth.
If a building cannot be constructed close to the north border of the property because of the North-side oblique line regulation to ensure sunshine to the adjacent property on the north side, the use of the SMB enables a reduction in the beam depth (the measurement from the top to the bottom of the beam) and lowers the height of the eaves proportionately, resulting in the effective use of the north side of the property.

 

(2) No creep behavior
Lumber is susceptible to long-term creep. Lumber-beam floors tend to experience creep, causing deflections in opening and closing of doors, for example. As the SMB is made of steel material, this means virtually no creep behavior. It is also ideal for the Skeleton Infill system houses*2, which are anticipated to become the future trend-setter, and the long-span floor framing systems needed for a large-space living room.

(3) Same construction performance as metal joints that use laminated lumber
SMB-TEC metal and TEC-ONE metal are compatible with the same bolt hole diameter and have similar construction performance. Thus, SMB-TEC metal can be used together with widely used TEC-ONE metal.

Thanks to the Building Center of Japan’s general evaluation, designers or engineers no longer need to conduct structure testing to prove safety of the connecting area of the “SMart BEAM floor framing system” for individual case. At the same time, its earthquake-resistance performance has been proven to satisfy the criteria set by the Housing Quality Assurance Act.

Tatsumi and Sumitomo Metals will actively propose the SMart BEAM method to building contractors nationwide, given the acquisition of its evaluation and its first construction case.

 
SMart BEAM Floor Framing System (image)
 
First property that adopted SMart BEAM Floor Framing System

 

Notes
*1: The Building Center of Japan is an organization designated by the Minister of Land, Infrastructure, Transport, and Tourism. It carries out evaluation, approval and certification of newly-developed building technologies and materials.


*2:Skeleton Infill system houses separate the building frame (skeleton) made of pillars and beams from the interior parts and equipment such as wiring and pipe fittings (infill.) As the skeleton has a longer service life than the infill, their separation facilitates reforms or repair of pipe fittings, etc.


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