The Japanese Building Standards Law requires that the opening of the outer wall in an area where there is a possibility of fire spread be fire protection specifications different from general windows called fire prevention equipment. The purpose of installing fire protection is to prevent the spread of fire from nearby buildings for a period of time.
This article describes fire prevention measures in areas where there is a risk of fire spreading.
Hello! It’s Yamaken.
Then, I will explain.
Range where fire may spread
The area where there is a risk of the fire spreading is the range of 3m on the first floor and 5m on the second floor from the adjacent land boundary.
The purpose of limiting the outer wall openings is to prevent fire from entering the room through the outer wall openings due to fire from a neighbor.
Buildings that require installation of fire protection equipment
Fire prevention equipment is required for buildings in quasi-fire prevention districts and fire prevention districts areas, Quasi-fire-proof buildings, and fire-proof buildings.
Regarding fire prevention equipment, it is regulated as follows by law, and basically 20 minutes of resistance is required.
When fire heat due to a normal fire is applied to the fire prevention equipment, it does not emit flame on any surface other than the heated surface for 20 minutes after the start of heating.
【Notification specification example】
・Iron plates with a thickness of 0.8 millimeters or more and less than 1.5 millimeters
・Steel-framed concrete or reinforced concrete with a thickness of less than 3.5 cm
・Dozo doors with a thickness less than 15 cm
・Those made of iron or glass mesh
・Wood plaques with a frame made of wood coated with a fire-retardant coating and having an indoor surface thickness of 1.2 cm or more
・Cover plates or gypsum boards with a thickness of 0.9 cm or more, and galvanized iron plates are installed on the outdoor surfaces
In the case of the standards specified by the Minister of Land, Infrastructure, Transport and Tourism, it must be glass with a wire in an iron frame or a product certified by the Minister of Land, Infrastructure, Transport and Tourism.
Thank you very much for watching until the end.
Please note that there may be mistakes in the English translation because I am not familiar with English.