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Safety

The innovative technology used in the KES System protects clients’ lives and assets in natural disasters.

It is almost impossible to know when natural disasters such as earthquakes and typhoons will occur. The KES System uses the latest technology to protect clients’ lives and assets in such events. When the Hanshin Earthquake hit Kobe City in 1995, all houses built there with the KES system survived entirely: this was dramatic proof of the effectiveness of our technology.

Patented metal joints recognized worldwide.
The KES System gives buildings strength and flexibility

Traditional Japanese wood jointing techniques are legendry for their beauty and ingenuity, but the joints do have some structural disadvantages. The KES System uses a unique design of metal plates to reinforce timber joints, achieving both beauty and great strength. The system has been patented not only in Japan, but also in the United States of America and in Canada, and is recognized worldwide.

The metal plates of the KES System are designed to easily receive and locate timber beams, making secure joints, and simplifying the buildability of projects.

The KES System fully utilizes the strength of the timber,
creating durable timber structures

The `Tsugite’ and `Shiguchi’ joints of traditional Japanese timber buildings are made without bolts or plates, but the method involves the cutting away of parts of the structural section. This reduces the strength of the wood, especially when timber sizes are small, and it is considered to be one of the inherent shortcomings of traditional Japanese timber structures.

The metal plates of the KES System are integrated into the beams and columns without cutting away large sections of the timber. This creates frames that are far more rigid than traditional or conventional timber structures.

Strength to weight, timber is an ideal structural material - lighter
and more durable than steel and or concrete

Comparison of the material strengths of timber, concrete and steel (testing the same weight of each material) (unit:kgf/cm2)

▲Experiments conducted by the Japan Housing and Wood Technology Center, HOWTEC, documented in the book `Timber and Japanese houses’

The `Tsugite’ and `Shiguchi’ joints of traditional Japanese timber buildings are made without bolts or plates, but the method involves the cutting away of parts of the structural section. This reduces the strength of the wood, especially when timber sizes are small, and it is considered to be one of the inherent shortcomings of traditional Japanese timber structures.

The metal plates of the KES System are integrated into the beams and columns without cutting away large sections of the timber. This creates frames that are far more rigid than traditional or conventional timber structures.

Resistant to forces - designed to anticipate natural disasters

The `Tsugite’ and `Shiguchi’ joints of traditional Japanese timber buildings are made without bolts or plates, but the method involves the cutting away of parts of the structural section. This reduces the strength of the wood, especially when timber sizes are small, and it is considered to be one of the inherent shortcomings of traditional Japanese timber structures.

The metal plates of the KES System are integrated into the beams and columns without cutting away large sections of the timber. This creates frames that are far more rigid than traditional or conventional timber structures.

Predictable and Versatile - Glued Laminated Timber is an advanced timber product

The use of solid timber posts and beams requires very careful attention to its grading because the timber quality varies between different native forests and environments. Also, in modern construction, timber is frequently used before it is fully mature, for example, before it is fully dried. This causes cracks and bending. The KES system, with its recommend specification of glued laminated timber, is the solution to the problem. Glued laminated timber consists of selected grade timber plates which have had a good drying period. Its compressive strength is 1.5 times greater than that of natural solid timber.

Established material - glued laminated timber has more than 100 years of history

Records show the use of glued laminated timber in building construction as early as1860, in England. Such timber buildings have stood for more than 100 years, and still welcome people with the warmth of their character. The technology of making glued laminated timber has advanced considerably since then. Today’s glued laminated timber has dramatically improved strength and water resistance. It has become a superior alternative to concrete and steel, and has been increasingly used in the design of larger scale buildings, such as gymnasiums, municipal offices and schools.

*It is believed that the first building using glued laminated timber in Japan was the Forest Memorial Hall in Tokyo, built in 1951, in which the wood formed a semi-circular structural arch.

Stability in a major earthquake - houses built with the KES System survived the Hanshin earthquake.

When the Hanshin Earthquake occurred in 1995, among the 73 houses built with the KES System, all of which survived the disaster, this house for Mr. & Mrs. N survived without a scar. It is a three-story residence in the worst hit area of the Nada District of Kobe City. The KES System protected our clients’ lives and their property in this massive earthquake, which destroyed a nearby three-storey concrete apartment building. This proved the structural strength of the KES System when compared to other construction methods.

Plans of the house
for Mr. & Mrs. N

This is a very narrow house, 3.64m wide. According to calculations based on the Building Standard Law of Japan, the load-bearing walls of the lowest floor of a three-storey building of this size should resist 11.83t in the X Axis and 12.74t in the Y Axis. However, during the earthquake, in this house, each KES connector was able to resist the 10t force of the initially vertical earthquake. Laboratory results have shown that a KES load-bearing wall can resist 4.7 times more force than a load-bearing wall as required by the Building Standard Law of Japan.

Voluntary Housing Labeling System introduced in Japan

With the introduction of the Housing Quality Assurance Act, in August 2002, owners of houses are able to assess the performance of their largest asset. The "Housing Performance Evaluation System" (HPES) covers performance criteria beyond the minimal standards of the Japanese Building Standards - for instance, durability, resistance to earthquakes, and energy consumption.

Comparison of housing performance, by construction method

(Created by Shelter. The ratings are subject to specifications. The larger number indicates better performance)

Laboratory test proved the strength of the KES System

Laboratory test: comparing the strength of load-bearing walls

1. KES systemPmax=2226kgf

2. Traditional Japanese timber structurePmax=1061kgf

The illustration shows a laboratory test of the strength of load-bearing walls. Two KES System shear walls were compared with a conventional cross-braced Japanese house wall with a standard specification. The test criteria were based on JISA1414. Test samples were;

1.KES System 140

140mm square laminated timber column, 140x240mm laminated timber beam, JM connectors at top of the columns, SB Connectors at bottom of the columns, and 11.1mm OSB board for the shear wall.

2.KES System 120

120mm square laminated timber column, 120x240mm laminated timber beam, SJ connectors at top of the columns, SB Connectors at bottom of the columns, and 9.5mm OSB board for the shear wall.

3. Conventional Japanese timber structure (Standard Specification for a house)

120mm Square column, 120x240mm beam, cross bracing with BP-2 plates

The tests showed the conventional double-braced wall bearing a load of up to 1.06 ton force. However, at that load, the sill of the wall became broken. The KES System 120 bore a load of up to 2.2 tons force. The KES System 140 bore a load of up to 3.5tons force, and in both cases the KES shear walls retained their structural integrity.

KES System