The process of exterior wall insulation transformation is a systematic process, which can not consider and deal with a link or an individual problem in isolation. Comprehensively plan and implement from the aspects of project initiation, thermal design standards, selection of external insulation technology suitable for single project, construction scheme design, construction organization, project acceptance, project use management, etc. In the process of planning and implementation, we should pay attention to a series of problems that may have important impact, and take corresponding technical measures to avoid them, so that the investment in external insulation transformation will not make some mistakes due to blindness and irrationality. From a technical and economic point of view, there are several aspects to pay attention to:
Thermal insulation mortar
Formulate energy-saving transformation scheme and energy-saving standards.
The doors and windows, exterior walls, roofs and other external protective structures of most existing hotel buildings do not meet the energy-saving requirements or do not meet the energy-saving requirements in one aspect. In addition, the energy-saving standards have been continuously improved, and the energy-saving transformation of various buildings has been continuously promoted, which is a permanent chapter in history. Hotels and hotels are the key building categories of energy-saving transformation, and the external wall insulation transformation bears the brunt. Therefore, in the process of project construction, the following aspects can not be ignored:
1. Basis for formulating energy-saving standards: the state stipulates the heat transfer coefficients of exterior walls, roofs, doors and windows. Therefore, during project construction, the thermal coefficients of doors, windows, roofs and exterior walls should be evaluated to determine the gap between them and the highest national equivalent standard, so as to determine the overall scheme, i.e. sequence, of door, window, roof and exterior wall reconstruction, so as to avoid hasty and blind reconstruction of a project. After a period of time, the reconstruction of another project led to repeated investment, destroyed the previous reconstruction project, and repeated the phenomenon of “zipper project” of urban road reconstruction.
2. Formulation of energy-saving standard: the heat transfer coefficient of the external wall shall be set according to the highest standard of the national building energy-saving design standard, and the thickness of the external insulation layer of the external wall shall be calculated to avoid the continuous energy-saving transformation of existing buildings in China, which will be carried out in a few years. An unreasonable decision. Because the external wall reconstruction project (especially high-rise buildings or high-end external decoration buildings) is the most difficult project among the doors, windows, roofs and external walls of the external envelope structure, with the largest quantities and economic investment, and the most interference to the surrounding projects, the comprehensive difficulty of door, window and roof reconstruction is relatively second.
Reasonable selection of short-term external insulation technology
For the external insulation transformation of existing buildings, especially public buildings, any external insulation technology is not applicable. First, pay attention to the correspondence between the selected external insulation technology and the climate characteristics of the climate area where the building is located. The requirements for external insulation technology are different in severe cold areas, coastal windy, rainy and high humidity areas, large temperature difference and dry areas. Second, pay attention to whether the external insulation technology can meet the requirements of building external decoration. Some exterior wall external insulation technologies can not paste face bricks on the highland board, while others can not meet the requirements of moisture-proof and seepage prevention. Third, we should pay attention to whether the external insulation technology can be combined with the building to ensure long-term safety, stable appearance quality and stable thermal performance. The external insulation project meets the design requirements. Fourth, it should be noted that the thermal conductivity of the external wall insulation material is large, which may not be able to deal with the nodes such as doors and windows, resulting in the external wall insulation transformation can not meet the design requirements. Fifth, we should pay more attention to the external insulation technology, which has not yet formed a complete technical system, can not be used normally or can not form an external insulation project that meets the design requirements.
The construction scheme and construction organization of external insulation transformation will have an impact on the owner.
The external insulation reconstruction of the existing project is a complete subcontract project. Improper preparation of construction scheme and construction organization in the early stage of construction will lead to project quality problems, safety accidents, environmental interference problems, fire safety problems, normal business interruption or complaints, city appearance problems and fines, difficult guarantee of construction period, damage of relevant parts and components and other problems, which will bring adverse effects or some losses to the owner.
Therefore, whether the project contractor can provide a complete and operable external insulation construction scheme, including construction qualification, safety qualification, professional construction management ability, practical work skills, personnel, management, equipment, qualification, etc., while professional ability is an important aspect of comprehensively forming the contracting ability, one-sided understanding of a certain aspect or using a “relationship” without comprehensive ability, It is easy to cause unexpected trouble. Because the external insulation transformation of existing buildings is more complex than new buildings to a certain extent.
Environmental problems caused by the construction of external insulation reconstruction project.
During the normal use of buildings, external insulation transformation is often carried out. Therefore, whether the external insulation construction will cause a series of troubles to normal work and life due to noise, dust, garbage or a large number of wet operations, or whether it is necessary to dismantle the original external decoration engineering structure and produce a large amount of construction waste, which not only pollutes the surrounding environment and personnel, but also increases a large amount of cost, Moreover, unnecessary damage may be caused to relevant parts such as doors and windows during the removal process. These are usually determined by the characteristics of the external insulation technology itself.
In addition, the external thermal insulation transformation of external walls in the process of normal use is often caused by improper selection of process, or improper selection of thermal insulation materials or other products prone to fire. As a result, a series of aftercare problems are difficult to solve.
The possible adverse effects of the acceptance after the transformation of the external thermal insulation project.
In 2007, the state implemented the energy evaluation and appraisal system for building energy-saving projects. For example, in some European countries, a series of unexpected losses will occur after the evaluation does not meet the standards, such as star qualification, economic penalties and the inability to hang signs that affect normal operation. The whole process must be carried out in strict accordance with relevant national standards, and can not be arbitrary and blind.
The selection of external insulation technology is prone to major mistakes, which may cause serious consequences.
Exterior wall external insulation technology is a new professional technology known to the construction industry in recent years, but the owners of existing public buildings are still very unfamiliar with it and know little about it. Therefore, when choosing the external insulation transformation technology, it is easy to listen to the introduction of acquaintances, or follow the practice of transforming the unit, or choose only according to the price, and it is also easy to decide the choice of external insulation technology. Blind selection or random purchase of the thermal insulation material, purchase of supporting materials from another party, and technical combination of construction personnel on site will often lead to problems such as cracking, falling off, unqualified acceptance, and even serious engineering rework.
Post time: Feb-11-2022