Extruded sheet for external wall

1. The core properties of extruded board for external wall

1. Efficient insulation and energy conservation

Advantages of closed-pore structure: The closed-pore ratio is as high as 99%, forming a dense vacuum cavity, the thermal conductivity is as low as 0.028W/(m·K), and the thermal insulation performance is 3-5 times that of traditional insulation materials (such as expanded perlite).

Significant energy-saving effect: 30mm thick extruded board is equivalent to the insulation effect of a 100mm thick brick wall, which can greatly reduce building heating and cooling energy consumption and meet the requirements of energy-saving specifications such as the Technical Standard for Exterior Wall Insulation Engineering (JGJ144).

2. High strength and wind pressure resistance

High compressive strength: The compressive strength is usually 150-400KPa (differentiated according to the model). It can withstand the load of exterior wall finishing layers (such as ceramic tiles and stone) and the impact of positive and negative wind pressure. It is especially suitable for external insulation systems of high-rise buildings.

Strong deformation resistance: The plate has good toughness and is not easy to crack. It can adapt to slight wall displacements and reduce the risk of insulation layer falling off due to structural deformation.

3. Hydrophobic, moisture-proof and impermeability

Low water absorption rate: Water absorption rate ≤ 1.5%(volume ratio), the dense surface layer effectively blocks water penetration, avoids degradation of thermal insulation performance after water absorption, and prevents dew condensation and mildew on the exterior wall.

Excellent weather resistance: In long-term dry and wet cycles, alternating freeze-thaw environments (such as severe cold areas, coastal high-humidity areas), the performance is stable and the service life can reach more than 25 years.

4. Lightweight and construction adaptability

Low density: The density is usually 28-45kg/m3, which reduces the wall load and reduces the load-bearing requirements of the building structure. It is suitable for the insulation renovation of the exterior walls of old and new buildings.

Convenient construction: It can be cut into any shape to adapt to complex parts such as door and window holes and lines; it adopts bonding + anchor fixation process and is compatible with plaster mortar and glass fiber mesh to form a complete insulation system.

5. Fire performance classification

Ordinary type (Class B3): Flammable, limited to temporary use in non-crowded places.

Flame retardant type (Class B1/B2):

Class B1 (refractory): Self-extinguishing after leaving the fire, and no molten droplets are produced during combustion. It complies with the "Burning Performance Classification of Building Materials and Products"(GB 8624) and is widely used in residential buildings, schools and other civil buildings.

Class B2 (combustible): It burns slowly in case of fire and needs to be used with fire-proof structures (such as fire-proof isolation belts). It is suitable for projects with moderate fire protection requirements.

2. Main application scenarios

1. external thermal insulation composite systems

Mainstream application: As an insulation layer, it is laid on the outside of the exterior wall to form a complete system of "bonding layer + insulation layer + plaster layer + finishing layer", which is suitable for various structural exterior walls such as concrete walls and masonry walls.

Finishing compatibility: It can be matched with various finishing layers such as paint, real stone paint, and ceramic tiles. Among them, high-pressure-resistant models (such as above 300KPa) are more suitable for ceramic tile finishing systems.

2. Exterior wall internal insulation system

It is used for indoor wall insulation, such as kitchens, toilets and other humid areas. The water repellency of extruded boards is used to avoid moisture on the walls. However, it should be noted that internal insulation may occupy indoor use area.

3. energy-saving renovation project

When renovating the exterior walls of old buildings, extruded boards can be directly pasted on the original walls, eliminating the need for large-scale demolition, reducing renovation costs and rapidly improving building energy efficiency.

4. special climate area

Severe cold/cold areas: Use thick extruded boards (such as 50-100mm) to solve the problem of thermal bridges on the exterior wall and prevent indoor dew condensation in winter.

Hot summer and warm winter areas: Use the thermal insulation of extruded panels to block summer solar radiation heat and reduce air conditioning load.

3. Construction key points and process specifications

1. pre-construction preparation

Base surface treatment: The wall surface needs to be flat, strong and clean, and the empty holes need to be removed and repaired. The flatness error is ≤4mm/2m, and the moisture content is ≤10%.

Material preparation: Check the thickness and fire resistance rating of the extruded board according to design requirements, and check whether the edge of the board is straight and whether the surface is damaged.

Tool equipment: cutting knife, adhesive mixer, anchor bolt, ruler, spatula, glass fiber mesh, etc.

2. Typical construction process (external wall insulation)

Missile control line and row plate

Plan the arrangement method of extruded sheets according to the wall size, and stick them from bottom to top starting from the strangling part, and the sheets at the inner and outer corners need to be staggered and interlocked.

Paste extruded board

Adhesive coating: Adopt "dot-frame method" or "strip adhesive method", and the bonding area is ≥30%-50%(adjusted according to the type of finish, the tile finish needs to be ≥50%).

Staggered seam splicing: Staggered seam of adjacent plates is ≥100mm, plate seam is ≤2mm, and when the seam width exceeds 2mm, it is filled with polyurethane foam caulking agent.

Install anchors

After the adhesive is cured (usually 24 hours), drill holes and install anchors at the design spacing (such as 600mm horizontally and 500mm vertically). The anchor depth into the base layer is ≥50mm, and the number of anchors per square meter is ≥6 (High-rise buildings are appropriately increased).

Plastering mortar construction

The first layer of plaster mortar has a thickness of 2-3mm, pressed into the alkali-resistant glass fiber mesh (overlapping width ≥100mm), and additional reinforcing mesh is laid at the inner and outer corners; the second layer of mortar covers the glass fiber mesh, with a total thickness of 3-5 mm.

Decoration layer construction

Paint finish: After the plaster layer is dried, scrape and apply putty and paint;

Tile finishing: Tile binder and seam sealing agent need to be used, and the compressive strength of extruded board is ≥300KPa.

3. Critical node processing

Door and window openings: Cut the plate into an "L" shape to wrap the opening, and lay a 45-degree oblique glass fiber mesh (200mm×300mm) at the four corners to prevent cracking.

Wall components: For example, air-conditioning brackets and pipe roots, extruded plates need to be cut tightly, and gaps must be sealed with sealant to avoid hot bridges.

Fireproof isolation strips: When using B2 extruded boards, isolation strips of Class A fire-proof material (such as rock wool) with a width of ≥300mm need to be set up according to the specifications, and one should be set up every two layers.

4. Matters needing attention

1. fire safety

It is strictly prohibited to use B3 extruded panels in high-rise buildings, and B2 panels must be equipped with fire isolation strips and fire blocking (such as around window holes) to ensure compliance with the Code for Fire Protection in Building Design (GB50016).

Open fire operation is strictly prohibited during construction, and fire-fighting equipment must be equipped on site.

2. Anti-cracking and peeling

Avoid using inferior adhesives or insufficient bonding area. The number of anchors must be calculated and determined based on the wall material (concrete/masonry) and the weight of the finish.

During winter construction, the ambient temperature needs to be ≥ 5 ℃ to avoid freezing failure of the adhesive.

3. Environmental protection and quality acceptance

Choose products that have passed environmental certification, avoid the use of extruded boards containing Freon foam, and reduce damage to the ozone layer.

After the completion of construction, the insulation layer thickness, bond strength, anchor bolt pulling force and other indicators need to be checked to ensure compliance with the design and specification requirements.

5. Comparison with other exterior wall insulation materials

material Thermal conductivity (W/(m? K)） Compressive strength (KPa) Water absorption (%) fire rating Applicable finishes Cost (yuan/m3)

Extruded Sheet (XPS) 0.025-0.030 150-400 ≤1.5 B1/B2/B3 Paint/Tile 300-600

Expanded polystyrene board (EPS) 0.035-0.041 100-150 ≤4 B1/B2 coating 200-400

rock wool board 0.040-0.045 80-120 ≥10 A-level coating 400-800

Polyurethane (PU) 0.020-0.025 100-200 ≤3 B1 level coating 800-1200

Summary of advantages:

High cost performance: Compared with EPS, extruded board has better insulation performance and stronger compression resistance, making it suitable for scenarios with higher loads;

Flexible construction: It can be adapted to ceramic tile finishes and expands the scope of application;

Outstanding moisture resistance: better than rock wool and EPS, suitable for exterior wall insulation in humid areas.

6. Selection and application suggestions

1. Select according to building height

Low-rise/multi-rise buildings (≤ 24 m):

Coating finishing: Select B2 extruded board, with compressive strength ≥ 150 KPa and thickness 30 - 50 mm;

Tile finish: B1 extruded board is required, with compressive strength ≥ 300 KPa and thickness 40 - 60 mm.

High-rise buildings (> 24 m):

Priority is given to B1 flame retardant type, with compressive strength ≥ 250 KPa, thickness 50 - 80 mm, and anchor bolt density increased to 8 - 10 pieces/m2.

2. Selection according to climate zoning

Severe cold areas (such as Northeast China): The thickness is ≥ 80 mm, and it is laid with double staggered joints to enhance the insulation effect;

Hot summer and warm winter areas (such as South China): 30 - 50 mm thick, focusing on heat insulation performance, and can be combined with reflective coatings to reduce solar radiation absorption.

3. Considerations for renovation projects

When the hollowing rate of the old wall is greater than 5%, it needs to be completely demolished, and when it is ≤ 5%, it can be partially repaired;

When the adhesive force between the insulation layer and the original wall is insufficient, the density of the anchor bolts needs to be increased or the adhesive-anchor bonding process needs to be used.

7. Common problems and solutions

problem reason solutions

hollow insulation layer Uneven coating of binder and too high moisture content of base surface Control the moisture content of the base surface to ≤ 10% to ensure that the bonding area meets the standard

Plate cracking Insufficient staggered joints, temperature difference deformation stress concentration Strict staggered joint construction, and additional reinforcement nets should be laid at the inner and outer corners

Wall dew condensation Insufficient insulation layer thickness and thermal bridges exist Review the insulation thickness and strengthen the insulation treatment of doors and windows and other nodes

Fire prevention acceptance failed The fire protection rating of the plate is not up to standard and no isolation belt is set Select flame-retardant plates that meet the specifications and supplement fire insulation belts

Due to its excellent comprehensive properties, extruded panels for external walls have become the mainstream choice in the field of building energy conservation. In practical applications, material quality and construction technology need to be strictly controlled based on project needs to ensure the safety, durability and energy conservation of the insulation system.