Primary issues in the construction technology of exterior wall insulation systems

There are many types of materials for exterior wall insulation systems, including insulation boards, adhesives, Fiber Glass, wood fiber, bonding mortar, plastering mortar, coatings (ceramic tiles), etc. Each material must be used in accordance with the requirements. For example, insulation boards are most commonly stacked in the open air at many construction sites. Exposure to the sun and rain can easily cause deformation and shrinkage of the board structure. At the same time, dirt on the surface of the insulation board will also affect the adhesion of the insulation board.

In particular, there are gaps between Fiber Glass. Filling the gaps with mortar can easily cause regular cracks on the surface of the plastering mortar. The bonding area of the insulation glass yarn is too small, and the phenomenon of hollowing during the pasting process will also affect the bonding force. If hollowing is obvious, it may As a result, cracks appear on the surface. The mortar layer is too thin to cover the alkali-resistant glass yarn. After the paint is applied, obvious traces of the glass yarn and anchor bolts will easily appear. If the plastering mortar layer is too thick or the second plastering layer is applied before the first plastering mortar layer is dry, shrinkage cracks may easily occur.
The cementing material used in exterior wall insulation systems is generally ordinary Portland cement. The hydration of cement at low temperatures progresses very slowly, and the early strength development is slow. If it encounters freezing temperatures again, it will undoubtedly make things worse. Once the unhydrated free water in the cement mortar freezes and expands, it will cause devastating damage to the mortar structure that has not yet formed sufficient strength. The final result is that the constructed mortar has no strength.
It is recommended to strictly follow the technical specifications in the JGJ144-2004 standard. Once the ambient temperature is lower than 5 degrees Celsius, the construction operation of non-antifreeze cement mortar on the exterior wall should be stopped immediately, and the external insulation of the exterior wall that has suffered freeze-thaw damage should be stopped immediately. For system engineering, depending on the degree of damage, it is recommended to take corresponding remedial measures for repair. If the damage is serious, it is recommended to tear it down and rebuild it.