Lately, along with the request of quality increase of buildings and decrease of greenhouse gases and the rejection of existing construction methods centered on sites, interest in dry and industrialization construction methods is increasing. Also, because necessity of the development of construction methods possible for construction period reduction and stable construction work with products is raised up, necessity of the modular construction which can reduce greenhouse gases grows by reducing construction periods, moving buildings themselves, or reusing materials of frameworks.
Modular construction is a construction method that after 70~90% production of all processes at a factory, assembling and finishing construction work are conducted at sites. With the strong points of reduction of construction periods, cost reduction, weight lightening, and so on by mass production, the method is applied to various buildings. Especially, since it can reflect diverse needs of residents, it receives attention as a method to response to residence problems like the expansion of residence sizes. But, modular construction is a dry construction method that construction members are united by welding and bolts using metal studs. So, because heat bridges occur at inside structural members and corner connection parts, insulation performance of a whole building is lessened. In addition, in case that indoor surface temperature drops under the dew point temperature due to the phenomenon of thermal bridges, secondary damages such as durability deterioration of construction members from the occurrence of surface dew condensation, aggravation of indoor air quality due to the gathering of mold, and so on can happen.
To solve these problems, in the courses of constructing work and module production, strengthening methods of insulation and air-tightness are needed. For them, in the construction course, crossing of modules should be prevented. For the parts of modules’ crossing, insulation and air-tightness should be guaranteed through insulation construction. Also, for all parts that modules mesh, from complete sealing work inside and outside, problems of mold and dew condensation can be prevented. And, in the course of module production, by applying the dual insulation method to inner walls, outer walls, and roofs, insulation performance of modules themselves should be secured. Especially, at the part of heat bridges originated from minute cracks, partial dew condensation can occur more severely due to moisture. So, for the securement of insulation and air-tightness performance, quality securement in the construction course as well as performance in the course of module production should be realized simultaneously.
Modular construction attracts attention as inevitable technology in modern society construction. Because reuse of construction members according to the production at a factory is possible, the value is evaluated highly in economic feasibility and environment-friendliness. Nonetheless, in case that insulation and air-tightness performance of modular construction fall down, since secondary damages are worried, securement of insulation performance in the courses of module production and constructing work is needed. Through this, to secure good quality like the performance of insulation and air-tightness through standardization of modules and regulations of the construction method should be preceded. It is considered that preparation of legislative bills and systems in accordance with them is necessary.