How to prevent the insulation layer of a building from bulging and cracking?
How to prevent the insulation layer of a building from bulging and cracking?
Bulging and cracking of the insulation layer are relatively common problems in insulation construction. The main reasons are as follows:
1. Material Moisture:
- Material Getting Damp: During material storage, transportation, construction, and finished product protection, insulation materials absorb moisture, leading to bulging and cracking. This is particularly common during rainy season construction if materials are not covered. Absorbed water degrades material performance.
- Improper Moisture Content Control: When the insulation layer uses a closed structure, if the material's moisture content is not properly controlled, failing to ensure it equals the material's average moisture content in the naturally air-dried state locally, bulging and cracking can occur.
- Lack of Ventilation Measures: Failure to implement proper ventilation measures during construction, such as not interconnecting ventilation ducts vertically and horizontally or not installing vent holes as required, prevents moisture within the insulation layer from escaping, causing bulging and cracking.
2. Waterproof Layer Leakage:
Waterproof layer leakage severely compromises the roof's service life and functionality. Common causes include:
- Leveling Layer Without Construction Joints: Lack of construction joints in the leveling layer as required by specifications leads to shrinkage cracks, which pull and crack the waterproof layer, causing leaks.
- No Additional Layer at Vulnerable Points: Failure to add an additional waterproof layer at critical weak points like pipe penetrations, drains, gutters, flashing, and roof corners. These areas are prone to leakage if not reinforced.
- No Isolation Layer Between Rigid Protection and Waterproof Layer: Absence of an isolation layer allows deformation and shrinkage cracking of the rigid protective layer, subsequently damaging the waterproof layer.
3. Poor Adhesion Between Insulation Layer and Substrate:
Poor adhesion leads to hollowing and detachment of the insulation layer. Main causes are:
- Improper Substrate Preparation: An uneven or unclean substrate surface, with dust, oil stains, or other contaminants, hinders bonding between the insulation material and the substrate.
- Improper Adhesive Selection or Irregular Application: Use of non-compliant adhesive mortar, or irregular application resulting in uneven adhesive thickness or insufficient bonding area, reduces adhesion strength.
4. Insufficient Drainage Slope:
Inadequate slope prolongs water retention on the roof, accelerating waterproof material aging and increasing leakage risk. Causes include failure to reasonably install sufficient drain pipes during construction, not constructing the roof slope according to design requirements, and poor control over the slope gradient thickness.
Corrective Measures
1. Strict Management of Material Selection and Storage:
- Material Selection: Choose appropriate insulation materials based on project needs and climate characteristics, ensuring material quality meets standards.
- Material Storage and Protection: Implement moisture-proof and waterproof measures during material storage and transportation to prevent dampening. Cover insulation materials during rainy season construction.
2. Standardized Construction Practices:
- Substrate Preparation: Thoroughly clean the substrate before construction, ensuring it is level and clean. Repair any defects present on the substrate.
- Insulation Layer Construction: Strictly follow construction process requirements for installing the insulation layer. Ensure insulation materials are laid flat, tightly butted, with joints tightly sealed and gaps filled solidly.
- Waterproof Layer Construction: After the insulation layer is complete, meticulously construct the waterproof layer, ensuring its integrity and uniformity. Add an additional layer at vulnerable points like pipe penetrations.
- Implement Ventilation Measures: Properly install ventilation ducts, ensuring they are interconnected vertically and horizontally. Install vent holes as specified to expel moisture from the insulation layer.
3. Enhanced Quality Control:
- Construction Process Inspection: Establish a quality inspection team during construction to rigorously inspect each stage, promptly identifying and rectifying issues.
- Post-Construction Maintenance and Inspection: After the roof insulation project is completed, conduct regular maintenance and inspections. Promptly repair any damage or cracks in the insulation and waterproof layers.
Implementing these measures can effectively resolve problems related to bulging, cracking, and water leakage in the insulation layer.
