The cracks are usually found on the exterior wall insulation system. The cracks on the exterior wall reduce the aesthetic of the building and it's service life. The problems of the exterior insulation system would waste the energy a lot. We study and summarize the solution during the construction experience.
The Cracks on the Exterior Wall External Insulation Layer.
The exterior wall external insulation system owns the good adaptation for the environment. The exterior wall external insulation would not cause cold and hot bridge and would not occupy the supplied building area. The external insulation system could protect the wall structure. But during the construction there is an issue would influence the building structure. The exterior would cause cracks during the construction. The building's aesthetic reduces a lot because of the cracks. There is also negative affect on the energy saving and service life. We are going to study on the reasons which cause cracks and the measures that prevent the exterior cracks. The XSP board is the main material for the cold places in the north so we would discuss about this material.
The plaster welded wire mesh is to prevent the exterior wall insulation cracks during construction.
The Different Kinds of the Exterior Wall Insulation Layer Cracks and the Reasons.
The irregular stacking for the insulation board.
When we stack the insulation board in the open air there would be dust on the board. The dust reduces the viscosity between the exterior wall and the insulation layer. There is great press on the board when we stack the insulation board irregularly. And the board would get deformed. When the board is used as exterior wall insulation layer the board would cause the mortar cracks easily. The board absorbs the moisture and the plastering layer would cause cement blocks. All of these are the reasons for the quality issue.
The mortar mixing.
For there is much chemical additives such as rubber powder in the mortar, mixing the mortar artificially cannot make sure that the mortar is uniform. So the mortar cannot meet the needs of the high quality construction. The stick force is weak with mortar block. It also can cause the cavity or blocks on the plastering mortar. More seriously it could cause the plastering mortar layer cracks. The insulation layer is installed from the plinth. The fiberglass mesh would get damaged and even get exposed if there is not waterproof and reinforced measure.
The treatment of the window.
During the construction, we should do the reinforcement measure on the four angles of the window and the fiberglass mesh, or there would be cracks on the angle. When we install for the window we should focus on the foamed material with based wall and the window. So the window would not crack and seep. When the position of the dripping groove is not appropriate the insulation system would be damaged.
The XPS insulation board.
We should do the interface agent on the XPS board before the construction. The stick force would be b and there is not freeze-thaw in the winter or expansion and contraction in the summer.
The fiberglass mesh and the galvanized wire mesh.
When there is not firm connecting with the fiberglass mesh and there is not 45° reinforced fiberglass cloth on the window, the exterior wall insulation system would cause cracks. When the hot dipped galvanized welded wire mesh is as the reinforced layer and there is not flatness processing, the cracks would occur on the exterior insulation layer.
The Measure Which Enhances the Function of the Exterior Wall Insulation.
The scientific stacking for the insulation board.
We should store the insulation boards indoors. When we store the insulation boards outdoors we had better cover the boards with something. The plastering mortar for the exterior wall insulation should be stored on the dry and cold place. So the insulation board could prevent the rain. If the board observes moisture or is on the rain, we should put the board outside and dry it.
The reasonable mortar mixing.
We should mix the mortar with machine during plastering mortar. We should avoid mixing the material artificially with stick or iron ball. For the mortar block or hard mortar, we cannot use them any more or it would reduce the stick force.
The plinth position.
To enhance the exterior wall insulation stabilization we should add the bracket system. And we use the waterproof mortar to set up the exterior wall layer.
The window position.
We should set up the 45° reinforced fiberglass mesh on the window angle according to the exterior wall insulation construction standard. We should do the treatment on the based wall before we fix the window with the foamed material. We should clean the oil point and extra mortar, and regulate the hollow surface.
The XPS insulation board.
We should do the interface agent treatment on the XPS insulation boards before we install the XPS board on the wall. And the series of treatment must in accordance with the scientific standard. The interface agent should stick bly with the XPS insulation board and have the particular grain gradation so that the adhesion is firm between the mortar and the XPS board.
The hot dipped galvanized welded wire mesh.
The hot dipped galvanized welded wire mesh use the qualified galvanized steel mesh. It makes a difference on the shrinkage of the cement mortar. The galvanized steel mesh is of corrosion resistance. The stick force would not get weak between the steel mesh and the mortar. The surface should be neat when we install the hot dipped galvanized welded wire mesh. We would anchor for the welded wire mesh so the U shaped card should suit with the anchor bolt. The anchor bolt should be regulated when we use it so that the board would not crack. The bracket and the protection angle device would protect the insulation boards. Especially on the corner position, the protection angle device could prevent the insulation board from the collision. The adhesion material should be made from the professional company and it's adhesion material is the high performance water brick bonding material.
The anti-alkali fiberglass cloth.
The construction should be in accordance with the technology standard and the connecting location for the fiberglass cloths should be on 5–10 cm. We choose the reinforced anti-alkali fiberglass mesh and its mesh opening is from 4 × 4 mm to 6 × 6 mm.
