Summary of types of ceilings utilized in the facility

新しい施設を建築するとき、既存施設を改修するとき、どのような天井を選ぶかによって、施設の機能性や安全性は大きく異なります。

天井は意匠性・見た目を左右するだけでなく、施設の防音性や湿度・温度、安全性にも影響します。そこで主な天井の種類と、改修の事例を紹介します。

Ceiling type of facility

天井の種類は大きく分けて２種類あります。「直天井」と「吊り天井」です。

「直天井」とは、建築物の屋根裏にあたる部分がそのまま天井になる構造を指します

「吊り天井」とは、屋根裏にあたる部分から金属のボルトなどで格子状の枠組みを吊り下げ、その表面に石膏などの天井ボードを取り付けて仕上げたものを指します。

特に体育館などの大型の施設の多くには、「吊り天井」が採用されています。天井裏に空間ができて、照明や空調、水回りなどの設備スペースを確保することが可能で、機能性やメンテナンス性に優れるためです。

一方、安全性には懸念が残る場合があります。東日本大震災の際に天井ボードが落下するなどの被害が相次いだため、大型の施設の吊り天井については、2014年に政府が耐震性について新たな基準を設け、「特定天井」として一定の安全性が求められるようになりました。

Example of earthquake resistance and retrofitting of suspended ceilings

When building a new facility, as well as for existing facilities, those with “specified ceilings” must be renovated to meet the new standards set by the government to ensure earthquake resistance.

Please refer to this article for more information on “specified ceilings.

The article ” Thorough Explanation of the Basics of “Specified Ceilings” and What Routes Should Architects Take?

 

The Japan Building Disaster Prevention Association has published examples of facilities with suspended ceilings that have been renovated in accordance with these new standards, some of which are introduced below.

7 types of facility ceiling retrofit methods

First, there are seven main types of methods for retrofitting suspended ceilings

go straight to the ceiling

This method involves removing the ceiling and using the building’s attic as the ceiling.

 

Direct ceiling and visual consideration by means of membranes, etc.

As above, this method involves removing the ceiling and then visually covering it with a membrane or similar material.

 

New earthquake-resistant ceiling

Instead of retrofitting existing ceilings, all ceilings are removed and new ceilings that meet earthquake resistance standards are installed.

 

Ceiling integrated with the building

This method involves removing the existing ceiling and installing a new ceiling that is integrated with the facility, not a suspended ceiling, while maintaining the space behind the ceiling.

 

Existing reinforced and retrofitted with earthquake resistant ceiling

This method increases earthquake resistance by installing grape shelves and new bracing on existing suspended ceilings.

 

Fall prevention measures

This is a method of preventing ceiling materials from falling in the event of a ceiling fall by, for example, stretching a net under the existing ceiling.

 

New lightweight flexible ceiling

This method replaces the ceiling material with a lightweight, soft material such as a membrane.

Case Study of Tokyo Jogakkan Memorial Auditorium

*Source: ” Japan Building Disaster Prevention Association: Case Studies of Seismic Retrofitting of Ceilings.

Case Study of Miraikan, the National Museum of Emerging Science and Innovation

*Source: ” Japan Building Disaster Prevention Association: Case Studies of Seismic Retrofitting of Ceilings.

Example of Gifu University Cafeteria

*Improved ceiling sound absorption to improve indoor reverberation time.

Frequency [Hz]	Reverberation time [sec]
	Before	After remodeling	Difference
250	2.2	1.4	-0.8
500	2.6	1.3	-1.3
1000	2.8	1.2	-1.6
2000	2.7	1.2	-1.5

Among the many different methods of refurbishing ceilings, Taiyo Kogyo especially recommends refurbishing ceilings using membrane ceilings. Here are some of the advantages of membrane ceilings.

Membrane ceilings" for facility construction and seismic retrofitting of ceilings

Membrane ceilings are a highly safe ceiling structure that does not fall under the category of specified ceilings, even in large spaces. It is lightweight, soft, and strong, and does not require hanging materials, allowing the design of large spaces without being limited by room area or ceiling height.

Even in the same renovation project, a membrane ceiling can reduce damage in the unlikely event of a ceiling fall, can catch falling objects from the building, and has a high design quality that is superior in terms of design. In addition, it has been numerically proven to improve the sound absorption coefficient of the ceiling and the reverberation time indoors.

For seismic retrofit of ceilings, please consider the option of membrane ceilings.

 

For more information on membrane ceilings, please see this page.

What is a Membrane Ceiling? It is the ceiling of the future: safe, comfortable, design-rich, and environmentally friendly.