Dangerous in the event of an earthquake! Why should you retrofit to earthquake resistant ceiling and what is the need for it?

Ceilings in buildings play a variety of important roles, such as regulating temperature and humidity, improving acoustics, and enhancing design. On the other hand, ceilings, especially those with a “suspended ceiling” structure, are a sensitive area that must be considered in terms of seismic risk, such as the risk of falling ceilings in the event of a disaster. Since the Great East Japan Earthquake, the government has set new earthquake resistance standards for ceilings, and the earthquake resistance of ceilings is increasingly being demanded. Now that there is an urgent need for seismic retrofitting of existing ceilings, we will review the necessity and options.

Dangerous when an earthquake strikes! What are suspended ceilings and specified ceilings with fall hazards?

In response to the string of damage caused by falling ceilings in the Great East Japan Earthquake, the government has designated suspended ceilings that meet certain conditions as “specified ceilings” and has decreed that specified ceilings must meet newly established seismic resistance standards. The government has mandated that newly constructed ceilings must be retrofitted, as well as existing ceilings. Building owners and those responsible for construction must understand the definition of specified ceilings to avoid any possible hazards.

Definition of specific ceiling

「脱落によって重大な危害を生ずるおそれがある天井」のことで、次のすべてに該当するものが特定天井です。

• Suspended ceilings (straight ceilings do not qualify as specified ceilings)
• Ceiling height: over 6m
• Area: over 200 m2
• Mass: Over 2kg/m2
• Installed in places where people use on a daily basis

 

These ceilings are often applicable to large facilities such as gymnasiums and airports. Please refer to this article for more information on specific ceilings. The basics of “specified ceilings” are thoroughly explained, and what routes architects should take.

Specific ceilings need to be retrofitted.

If the ceiling of a building has a suspended ceiling and falls under the above specified ceiling, it is necessary to review the structure or renovate the existing ceiling in order to avoid falling ceilings and other hazards.

To confirm compliance with the newly established earthquake resistance standards, the earthquake resistance of the ceiling is checked using a verification method known as the “route” established by the government.

 

The seven main methods of retrofitting existing ceilings and examples of retrofitting in accordance with the new safety standards are described in the following article.

‘ Summary of Types of Membrane Ceilings Utilized in Facilities ‘

As described in the case study, Taiyo Kogyo recommends “membrane ceilings” as a new option to dramatically increase earthquake resistance and safety when retrofitting specific ceilings.

Membrane ceiling" as an alternative to earthquake-resistant 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 light, soft, and strong, and does not require hanging materials, allowing for the design of large spaces without being limited by room area or ceiling height. Reinforcing the earthquake resistance of existing suspended ceilings requires large-scale construction using many materials, such as installing new grape shelves and braces. While this method may reduce the risk of a ceiling falling, it does not limit the damage in the event of a fall. This is where membrane ceilings, which replace existing ceiling materials with membranes, become an effective option. Here are some of the features of membrane ceilings, which excel in both functionality and seismic safety.

 

For more information on membrane ceilings, please see this page. What is a Membrane Ceiling? It is the ceiling of the future, rich in design and environmentally friendly.