Comprehensive analysis of common problems in external wall insulation

The external wall insulation system in Shandong plays an important role in building energy conservation, but various problems often arise during construction, use, and maintenance. Based on search results and industry cases, the following are the main common problems and their causes of external wall insulation systems:

1、 Construction quality issues

Hollow drum and detachment issues

Insufficient bonding strength: Some developers choose inferior materials to reduce costs, resulting in insufficient bonding strength between the external wall insulation layer and the base layer. According to data from the Ministry of Housing and Urban Rural Development, among the 30 projects randomly inspected in a certain city, the qualified rate of external wall bonding strength is less than 60%

Cutting corners in anchoring system: The standard requires a minimum of 5 and a maximum of 14 anchor bolts per square meter, but some construction sites have compressed it to 3-4 bolts per square meter, resulting in a decrease of over 60% in wind resistance load capacity

Improper grassroots treatment: The exterior walls of the frame structure are prone to insulation layer damage due to masonry deformation at the joints between concrete beams, columns, and masonry

Construction process defects

Insufficient curing period of insulation board: The insulation board, which has been aged for less than seven days, continues to shrink after being placed on the wall, resulting in the mortar layer being torn apart

The construction of the plastering layer is not standardized: double-layer mesh reinforcement was not used, and the thickness of the surface layer is less than 3mm, resulting in cracking of the protective layer

Improper handling of special areas: The outer side of the corner of the door and window opening is not covered with mesh cloth along the 45 degree direction, resulting in stress concentration

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2、 Material selection issue

The material performance does not meet the standard

Insufficient density of insulation board: Some companies use insulation boards below 18kg/m ³ (standard is 18-22kg/m ³), resulting in insufficient strength

Falsification of Fire Protection Rating: Selling B1 level flame-retardant materials as A-level non combustible materials poses significant safety hazards

Virtual standard of thermal conductivity: some enterprises use recycled polystyrene foam board, and the thermal conductivity is far higher than the qualified standard

Problem with supporting materials

Poor quality of bonding mortar: the content of polymer lotion is reduced from 5% of the standard to below 2%, and the bonding strength is less than 0.1MPa

Anchor bolt quality defect: 15% of anchor bolts have a tensile bearing capacity of less than 0.3kN, far below the standard requirement of 0.8kN

Insufficient performance of mesh fabric: low weight per unit area, insufficient application of alkali resistant coating layer

3、 Usage and maintenance issues

Cracking issue

Temperature induced cracks: caused by differences in thermal expansion and contraction performance of different materials, commonly found at the junction of ring beams and brick masonry

Dry shrinkage cracks: Insufficient maintenance of the surface layer, resulting in rapid dehydration during construction under weather conditions such as sun exposure

Structural cracks: Uneven settlement of the foundation leads to shear and tensile forces in the wall, exceeding the tensile strength of the wall

Water seepage problem

Incorrect handling of conduit exiting the wall

There is an issue with the closure of the eaves

Damage to the protective layer causes the insulation material to absorb water

Difficulty in maintenance

High maintenance costs and risks for high-rise buildings

Partial repairs can easily cause color differences and overall damage

Durability cannot be guaranteed after maintenance

4、 Environmental factors have an impact

Wind pressure influence

The non nail bonding method used in coastal areas or high-rise buildings can easily cause the insulation panels to be damaged by wind pressure

Special locations such as Jiangjingfang have higher requirements for resisting wind loads, and ordinary external insulation processes are difficult to meet

Temperature variation

The temperature difference between day and night causes the material to repeatedly expand and contract

Freeze thaw cycles accelerate material aging

Other factors

Degradation of polymer materials caused by ultraviolet radiation

Acid rain corrodes the protective layer

Destruction caused by biological factors (mold, plant roots)

5、 Prevention and Solutions

Construction phase

Strictly control the bonding area (≥ 50%) and anchoring quantity (≥ 5 pieces/㎡) according to the specifications

Strengthen grassroots treatment and use interface mortar

Strengthen special areas (such as door and window openings)

Material selection

Select products from legitimate manufacturers and verify the testing report

High rise buildings should prioritize the use of Class A fire-resistant materials

Ensure that the insulation board has a sufficient curing period (60 days in natural environment)

Maintenance management

Regularly check the condition of the protective layer

Timely repair hollowing and cracking areas

Establish archives for external wall insulation system

By systematically analyzing various issues with external wall insulation, building owners and construction parties can more effectively prevent and solve insulation system failures, extend the service life of buildings, and ensure residential safety.

Shandong Huaneng Insulation Materials Co., Ltd. is a pipeline insulation manufacturer in Linyi. As an integrated insulation and decoration manufacturer in Shandong, our main products include integrated insulation and decoration, pipeline insulation, exterior wall insulation materials, extruded polystyrene board, thermosetting polystyrene board, and rubber insulation. If you need it, you can contact us by phone.