How to install exterior wall insulation materials

With the continuous improvement of building energy-saving requirements, external wall insulation systems have become a "standard" for new and renovated buildings. A high-quality insulation system can not only significantly reduce building energy consumption, but also improve living comfort and building durability. So how to install external wall insulation materials correctly to achieve the expected effect? This article will provide you with a comprehensive operation guide from material selection to construction details.

1、 Pre construction planning and material selection

1.1 Material Performance Comparison: Analysis of Mainstream Insulation Boards

When selecting insulation boards, key indicators such as thermal conductivity, fire rating, compressive strength, and breathability should be considered to ensure that their performance meets design requirements

Materil	Thermal conductivity(W/m·K)	Fire rating	Compressive strength(kPa)	Water absorption rate(% vol)	Applicable scenarios
Rock Wool Board	0.035~0.045	A级	≥40	≤1.0	High rise/fire prevention key areas
SEPS	0.030~0.033	B1级	≥100	≤3.0	Conventional residential buildings
XPS	0.028~0.032	B1/B2级	≥150	≤1.5	Basement/ground insulation
Rigid polyurethane foam	0.022~0.026	B1级	≥150	≤3.0	Alien structure/low temperature environment

Attention:

Rock wool board has an advantage in high-rise and public buildings due to its A-level non flammability (referring to the national standard GB8624)

Attention should be paid to the hydrophobicity index of materials in humid areas of the south (the hydrophobicity rate of rock wool should be ≥ 98%)

Choosing rock wool board with double-sided coating can effectively reduce dust release

 

1.2 Design Confirmation and Technical Disclosure

Verify the insulation layer thickness and node treatment plan in the design drawings

Clearly define the location of expansion joints (recommended to be set every 2 floors or ≤ 6m)

Prepare a specialized construction plan and have it approved by experts (especially for thin plastering systems)

 

2、 Detailed explanation of the six steps of core construction operation

2.1 Grassroots treatment (decisive foundation)

Strength testing: The tensile strength of the concrete wall is ≥ 0.3MPa (tested with an adhesion tester)

Leveling treatment:

Remove hollow/cracked parts and repair with polymer mortar

If the error is greater than 4mm, leveling is required, and the flatness should be ≤ 3mm/2m ruler

Cleaning and dust removal: Rinse with high-pressure water gun and air dry for 72 hours

Interface treatment: Apply specialized interface agent (enhance adhesion, seal dust)

2.2 Rock wool board bonding (full bonding+strip bonding process)

Adhesive preparation:

Use specialized bonding mortar (such as cement-based adhesive)

Mix according to the manufacturer's ratio and let it stand for 5 minutes before stirring again

Paste method:

Full adhesion method: full scraping of adhesive on the back of the board (suitable for flat walls/low floors)

Strip bonding method: Apply 80mm wide adhesive strip along the edge of the board, and apply Ø 100mm adhesive cake at the center of the board (spacing ≤ 200mm)

Adhesive area ≥ 60% (due to the high weight of rock wool)

Key points for laying boards:

Construction from bottom to top, staggered laying (vertical joints staggered by ≥ 200mm)

Perform staggered interlocking treatment at the positive corner

Timely remove excess adhesive slurry extruded

2.3 Mechanical anchoring reinforcement

Anchor bolt selection:

Nylon expansion sleeve+galvanized steel nail (length=insulation layer thickness+anchoring depth 50mm)

It is recommended to use screw in anchor bolts for high-rise/coastal areas

Installation specifications:

Distance from the edge of the board ≥ 50mm, anchored into the substrate ≥ 50mm

Quantity standard:

Middle wall: ≥ 6 pieces/㎡

Corner area: ≥ 8 pieces/㎡ (including door and window openings)

Increase the density of the first and upper floors by 20%

The anchor plate must be pressed 1mm into the plate surface

2.4 Construction of plastering layer (key waterproof barrier)

First layer of plastering:

Fully laid alkali resistant mesh cloth (standard type ≥ 130g/㎡)

Buried in a plaster adhesive with a thickness of about 1.5mm

Anchor reinforcement:

Cutting 200 × 300mm mesh fabric to strengthen anchor bolt position

Window and door openings are laid at a 45 ° angle with a reinforced mesh of 300 × 400mm

Yin Yang corner treatment:

Double edged mesh fabric with a width of ≥ 200mm

Use PVC corner protectors (width ≥ 40mm)

2.5 Construction of Decorative Layer

Maintenance time: The plaster layer should be maintained for at least 48 hours in a 20 ℃ environment

Putty leveling: Use flexible exterior wall putty (thickness ≤ 2mm)

Paint/Decorative Bricks:

Elastic coating: It is recommended to use spraying technology to improve compactness

Bricklaying system: Flexible tile adhesive and grout must be used

 

3、 10 guidelines for avoiding pitfalls

Strictly control node waterproofing: reserve a 10mm gap around the window frame and fill it with foam adhesive, and apply weather resistant sealant on the outside

Rock wool special tools:

Cut with tungsten steel knife (to avoid fiber tearing)

Operators wear puncture resistant gloves

Construction environment requirements:

Environmental temperature of 5-35 ℃, wind force ≤ 5 levels

Construction is not allowed on rainy days or within 24 hours of rain forecast

Transportation and Storage:

Rock wool board is placed vertically to prevent pressure damage

Keep away from sources of fire and chemical solvents (especially polystyrene materials)