Wind-resistant and fire-retardant performance

Typhoons and torrential rainstorms repeatedly hit Japan every year. We guard residences against storms via designs that ensure the strength and waterproofing of buildings.
In addition, as a precaution against fires breaking out and spreading, due to neighborhoods with houses lined so close together, we use fireproof material to achieve high fire-retardant performance.

Fire-retardant and fire prevention

We offer a safe residence to stop fire spreading from the neighborhood or within the house.

External wall

SFC board external walls with fire prevention structure reassure you against a fire in the neighborhood

Eaves and external walls situated just 3m from a fire in a neighboring house may be exposed to temperatures of 840°C. When the SFC board, Heim's external wall material, is exposed to such temperature, the surface temperature of the board remains at around 80°C, which is much lower than the ignition temperature of wood (260°C). This ensures safe evacuation and minimizes the impact on valuable furniture.

Dula stone external wall with semi-fireproofing for 45 minutes

Ordinary painted outer wall
Durastone outer wall

As the material applied to and pigment painted on the Dula stone external wall are inorganic substances, those are unburnable. The photos show results of combustion tests with burner.

Fire prevention structure of Heim's external wall

Heim's external walls used for real housing are SFC boards, with glass wool attached to restrict the temperature. The surfaces of the walls facing the room, meanwhile, are plasterboards, which exude moisture when exposed to high temperature. These three materials compose the structure of the external walls, while we also offer semi-fire proofing external walls, using rock wool as the insulation*2.

  1. *1Only for semi-fire proofing specifications.
  2. *2Only for the fire guard portion.


Unburnable roof, seamless structure to prevent leaping flames

The Hyperdulatic roof is roofed with overlapped fireproofing long stainless steel, jointed without bolts, with no gaps through which fire can creep. The ceramic tiles and brooks also used for the sloped roof likewise represent fire retardant materials.

15-minute fire prevention structure to prevent fire from spreading from one room to another

In case a fire occurs in the house, it dose not spread to other portions

The 12.5mm reinforced plasterboards chemically react and emit moisture when they are exposed to heat. The inner walls of Heim demonstrated a clearance of 15 minutes fire retardant performance.

Inside Heim, the ceilings and walls are covered with reinforced plasterboards (12.5mm) or moisture-proof plasterboards (15.0mm). Ceilings, where the temperature rises fast in the initial stages of the fire, are doubly covered with reinforced plasterboards. Factory built Heim also has a very high air-tightness structure. Assuming the door is closed when you evacuate, it reduces the air supply and prevents fire from spreading to other rooms for 15 minutes.

Various kinds of fire alarms are installed according to the plan

Residential fires are sometimes found too late to be extinguished, meaning early identification is vital to prevent fire disaster. Various kinds of fire alarms are installed in living rooms, kitchens, staircases, and open ceiling in Heim, according to the plans and lifestyles. Also, we cooperate with Secom Company, one of the leading companies in Japan, specialized in the areas of fire prevention and security, which provides its security system

Wind and rain-resistant

Heim is designed to reduce damage from typhoons and rainstorms

External wall

The SFC external wall panels flexibly withstand wind force

In bending tests assuming wind pressure, SFC boards demonstrated flexibility five times higher than that of aerated lightweight concrete boards (ALC boards). SFC boards can also resist 1,600kg of wind pressure, which is equivalent to a wind force of 60m/sec exerted on a penthouse at the top of a three storey building.

What is the SFC board for the external wall?

The SFC board was originally developed by the Sekisui Company for use as an external wall material. It is manufactured by heating and compressing mixtures of wood fibers and thermosetting cements with a 2,000 ton pressing machines. The mixing ratio of the wood fiber is adjusted at surface, middle and reverse portions of the board, meaning it has both the hardness and strength of concrete and flexibility of wood.

Ceramic tiles and SFC boards: a combination of virtually impermeable materials.

Ceramic tiles are so reliable for waterproofing that they are commonly used for facilities such as bathroom. In particular, the tiles used for Heim's external walls have very low permeability. The tiles are also designed to resist acid and alkali, meaning the building is protected against depressive conditions such as acid rain. The SFC boards used as base sheets for the ceramic tiles are a high-density material, manufactured by heating and pressing 50mm thick raw material until it becomes 12~16mm thick, using a 2,000 ton pressing machine. As it has low permeability, namely 10 times lower than that of ALC board, it can be used for external walls, untilled or in any other way, except painting.

  • Water immersion tests by material
  • *The photographs show conditions during the first day of the test.
SFC board
Lightweight foam concrete
Mortar boards

Tests demonstrate the complete waterproofing

Based on previous experiences in meteorological observation, it is known that the stronger the wind, the lower the rainfall, and vice versa. A combination of wind and rain occurring once every half century would be equivalent to a wind velocity of 35m/sec x rainfall 60mm/h (average value for 10 minutes, wind velocity being converted to the velocity at the height of the house roof). Under these conditions, the amount of water hitting the vertical wall of the building corresponds to rainfall of 285mm/h. We artificially reproduced this situation for Heim and confirmed the impermeability of every joint and portions of the roofs and external walls.


Flat roof, a suitable design against strong wind

Japanese style roof tiles, with the ordinary fixing method, may become loose at 25~30m/sec wind and sometimes begin to fly away. However, Heim's flat roof is a suitable form to minimize the effects caused by strong wind blowing up and down as well as from earthquakes, thanks also to its lightweight nature.

Long and boltless folded plates, ensuring no water leakage

There are no structural gaps through which water can seep, since the boltless stainless steel plate roof materials overlap. As the roof material is long stainless steel plate, reducing the number of joints improves the waterproofing property.

We specially developed the material, design and fixing method for the Brook roof tile, which represents a safety measure against wind and rain,.

Double clip method

The brook roof tiles used for the sloped roof type in Heim are a mixture of cement and polymer fibers firmly pressed to form precisely molded roof tiles. The material is impermeable by nature and also has a special shape for waterproofing, known as a rib structure against driving rain, while the increased size of the roof tiles also allows a reduction in the number of joints. The brook roof tiles are fixed to the roof with special stainless steel clips and ring nails. Wind-resistant tests verified the fact that the fixed roof tiles did not loosen or become ripped away when exposed to wind of 60m/sec.