Features of membrane structural buildings

Membrane structural buildings have many features that enrich people’s lives and the environment by taking advantage of the lightweight and high strength of the materials.

Large-span liberating space can be realized.

Membrane materials are extremely lightweight compared to ordinary building materials. Taking advantage of its lightness, membrane structural buildings are pillarless and vast.

Bright space created by high light transparency

The use of white membrane materials keeps the room bright during the day and reduces lighting costs. At night, lighting creates a fantastic space.

Shortened construction period

Large-area membrane panels can be installed at once using the latest construction methods. Similarly, removal work can be easily performed.

Contributes to cost reduction

The lightweight materials used in the construction of the building enable it to reduce construction costs. White membrane materials also contribute to reduced lighting costs due to their high translucency.

Material that combines high strength and flexibility

Membrane materials that have passed strict strength tests can be used in a wide range of specifications while maintaining high strength and durability.

Suppresses temperature and blocks UV rays

The white membrane roof has a solar reflectance of more than 75%, which is equivalent to the high reflectance coatings typical of cool roofs. This results in a favorable thermal environment in the space covered by the membrane roof. It also significantly reduces UV rays, creating a safe space for those who are concerned about the effects of UV rays.

Resistant to wind and snow

Did you know that there are currently more than a dozen membrane-roofed floating bridges in operation around the Okinawa Islands in the rampant typhoon area? This is because the membrane is resistant to salt damage, durable, and its light weight is advantageous to the structure of the floating bridge body. Regarding durability against strong winds, membrane materials certified as building materials have high strength, and by designing in accordance with the Building Standard Law, membrane structure construction can be strong enough to withstand typhoons.

Attic surface temperature and sensory temperature by material

The surface temperature under the roof, mean radiant temperature (MRT), and the operative temperature (OT) experienced under the roof due to radiant heat were measured for three types of roofing materials: membrane, metal, and slate.
As a result, it was confirmed that membrane roofs have a lower sensory temperature by 1.5°C compared to metal roofs and by 3.5°C compared to slate roofs.
The maximum illumination is 16,000 lx, which is much brighter than that of metal and slate roofs.

Membrane roof

Air temperature: 35°C / Attic surface temperature: 40°C
Mean radiant temperature {MRT}: 37°C/feeling temperature {operative temperature OT}: 36°C
Maximum illumination: 16,000 lx

Metal roof

Air temperature: 35°C / Attic surface temperature: 49°C
Mean radiant temperature {MRT}: 40°C/feeling temperature {operative temperature OT}: 37.5°C
Maximum illumination: 4,700 lx

Slate roof

Air temperature: 37°C / Attic surface temperature: 55°C
Mean radiant temperature {MRT}: 42°C/feeling temperature {operative temperature OT}: 39.5°C
Maximum illumination: 2,400 lx

Also contributes to the reduction of the heat island effect

Membrane roofs have high solar reflectance, which increases the rate at which solar energy is reflected back into the sky and prevents heat absorption. This promotes mitigation of the urban heat island effect.

Reduction of CO₂ emissions

When the CO₂ emissions of membrane materials are calculated based on CO₂ emission units* and compared with the actual use of the material as a building material,
the CO₂ emissions per square meter of membrane material are approximately 3 kg-CO₂/m2 (for Type A membrane material), which is by far the smallest amount compared to other materials.
The secret lies in the membrane material’s overwhelming lightness as a building material, at approximately 1 kg per square meter.

Comparison in terms of CO₂ emissions per square meter of building material (kg-CO₂/㎡)

Calculation conditions

	Material name
	Aluminum honeycomb	Glass	Polycarbonate	Folded plate plated copper plate	Type A membrane material	Type C membrane material	Type B membrane material
Thickness (mm)	105	6.8	6	0.8	0.6	0.54	0.54
CO₂ emissions per unit of production ( kg-CO_2/kg )	9.25	2.27	5.08	1.12	3.14	2.39	1.96
Weight kg/㎡	28	18	7.2	12	1	0.82	0.65
CO₂ emissions per square meter ( kg-CO_2/㎡ )	259.06	40.91	36.58	13.38	3.14	1.96	1.27

CO₂ emission of polycarbonate per unit of production is based on “Chemical Economics Research Institute 1993.”

CO₂ emission of other materials per unit of production (production to distribution stage) is calculated by our company based on the “1995 Three Banks' Consolidated Review.”

Comparison in terms of CO₂ emissions per kg of building materials (kg-CO₂/kg)

Membrane materials weigh about 1 kg per square meter while other building materials weigh 7 to 28 kg per square meter. This will lead to a significant reduction in CO₂ emissions.

Earthquake resistant

Membrane materials are extremely lightweight compared to ordinary building materials. And lightness is very advantageous against earthquakes.
Since the seismic energy of an earthquake is proportional to the weight of the roof, the lightness of the membrane material significantly increases the earthquake resistance of the building.
In addition, flexibility, one of the characteristics of membrane materials, follows deformation during earthquakes, making it resistant to breakage and shattering. It can be said that this material is less likely to cause secondary disasters due to falling.

Metal roof

Prone to fall and collapse due to damage
Prone to secondary damage from falling objects

Membrane roof

Rupture is unlikely to lead to immediate fall
Less likely to cause secondary damage from falling objects

Four basic types of membrane materials for construction

Fluoropolymer/Glass fiber membrane material
(Type A membrane material)

A membrane material consisting of glass fiber coated with fluorocarbon resin Noncombustible material with durability expected to be more than 30 years With the advent of this membrane material, the premise that tents are temporary has been overturned, and membrane materials are now used in permanent buildings.

Details of fluoropolymer membrane materials

PVC/Glass fiber membrane material (Type B membrane material)

A membrane material consisting of glass fiber coated with PVC (polyvinyl chloride resin). The base fabric is made of glass fiber, which increases fire resistance and strength. Durability is about 15 years. It is a certified noncombustible material and can be used in construction for a variety of applications.

PVC/Synthetic fiber membrane material (Type C membrane material)

A membrane material consisting of synthetic fibers, such as polyester fibers, coated with PVC (polyvinyl chloride resin) Durability is about 15 years. Class 2 disaster prevention product It can also be used in Article 22 areas of the Building Standards Act depending on the application.

Film for membrane structure (ETFE film)

Film for membrane structure made of fluoropolymer ETFE molded into film form. There is no base fabric and high transparency like glass. Class 1 flame retardant product, whose durability is expected to be more than 20 years. In terms of fire resistance, it can currently be handled in the same manner as Type C membrane materials.

Details of ETFE Film

Three types of technologies for architectural membrane materials