Sika Sikatherm 830 XPS
Sika Sikatherm 830 XPS
Sikatherm 830 XPS is an extruded polystyrene (XPS) rigid insulation board with closed cell structure, offering excellent thermal insulation, high compressive strength, and very low water absorption. Designed for protected membrane roofing systems where the insulation is laid on top of the waterproofing membrane. Available in 25, 40, and 50 mm thicknesses, 1,200 x 600 mm per piece.
Sikatherm 830 XPS — Extruded Polystyrene Roof Insulation Board
Sikatherm 830 XPS is a lightweight, rigid, high-performance insulation board made of extruded polystyrene with closed cell structure. Supplied in different thicknesses and with different edge designs (square edge and shiplapped), it is suitable for a wide variety of roofing systems and waterproofing systems.
Key Features
- Excellent thermal insulation — thermal conductivity of just 0.028 W/(m·K)
- High compressive strength of 300 kPa for pedestrian and equipment loads
- Closed cell structure with very low water absorption (only 1.0%)
- Lightweight and easy to handle — density of just 35 kg/m³
- High compatibility with most commonly used materials
- Low water vapour transmission (1.9 ng/(m²·s·Pa))
- Easy to apply — direct lay installation
Applications
Sikatherm 830 XPS is designed for protected membrane roofs, where the waterproofing membrane is laid directly on the roof deck, with XPS insulation placed on top to provide both thermal insulation and physical protection of the membrane. Suitable for:
- Schools, hospitals, and public buildings
- Office buildings
- Retail developments
- Industrial developments
- Green / garden roofs
- Roof terraces and patio areas
- Roof top car parks
Why Choose Sikatherm 830 XPS?
- Ultra-Low Thermal Conductivity: 0.028 W/(m·K) effectively blocks solar heat transfer into the building, improving energy efficiency
- High Load-Bearing Capacity: 300 kPa compressive strength suitable for pedestrian walkways, terraces, and car parks
- Moisture Resistant: Closed cell structure keeps water absorption to just 1.0%, maintaining insulation performance even in prolonged wet conditions
- Protects the Membrane: Placed above the waterproofing membrane, it shields it from UV, mechanical damage, and temperature fluctuations
- Extended Shelf Life: 60 months (5 years) for long-term storage flexibility
Packaging and Dimensions
| Item | Specification |
|---|---|
| Dimensions | 1,200 × 600 mm per piece |
| Available Thicknesses | 25 mm, 40 mm, 50 mm |
| Edge Designs | Square Edge and Shiplapped |
Technical Specifications
| Property | Value |
|---|---|
| Material | Extruded Polystyrene (XPS), closed cell structure |
| Density | 35 kg/m³ |
| Compressive Strength | 300 kPa |
| Thermal Conductivity | 0.028 W/(m·K) |
| Water Absorption | 1.0% |
| Water Vapour Transmission | 1.9 ng/(m²·s·Pa) |
| Shelf Life | 60 months (5 years) |
Important Notes
- Do not leave boards exposed to prolonged sunlight — UV causes surface degradation
- For extended outdoor storage, cover with opaque/light-coloured sheeting
- Do not store near open flame or other ignition sources
- Avoid contact with volatile compounds and chemical solvents
- Ensure tight butt joints during installation; shiplapped edge design helps reduce thermal bridging
FAQ
What thicknesses are available for Sikatherm 830 XPS?
According to the product data sheet, Sikatherm 830 XPS is available in 25 mm, 40 mm, and 50 mm thicknesses, with each piece measuring 1,200 x 600 mm. Both square edge and shiplapped edge designs are available.
What is a protected membrane roof system?
A protected membrane roof is a system where the waterproofing membrane is laid directly on the roof deck, with XPS insulation boards placed on top. This design allows the insulation to protect the waterproofing membrane from UV exposure, temperature fluctuations, and mechanical damage, extending the membrane's service life. Sikatherm 830 XPS is specifically designed for this system.
How much load can the XPS board withstand?
Sikatherm 830 XPS has a compressive strength of 300 kPa, making it suitable for pedestrian walkways, terraces, garden roofs, and roof top car parks that require load-bearing capability.
