Waterproof Breathable Membrane Manufacturer
KOSITE manufactures waterproof breathable membrane rolls in Indonesia for roof underlays and exterior wall protection, with OEM printing and private-label packing. Select a roof or wall grade by its controlled technical data sheet, water resistance and vapor properties, not by GSM alone.
Controlled Membrane Grades and Technical Data
Three-layer PP nonwoven / breathable film / PP nonwoven. Standard roll: 1.50 m x 50 m (75 m²). Nominal basis weight tolerance: ±5%. The linked TDS defines the application, test methods, tolerances and limitations for each grade.
150 gsm Wall WRB TDS, Rev. 01
120 gsm Roof Underlay TDS, Rev. 01
130 gsm Roof Underlay TDS, Rev. 01
140 gsm Roof Underlay TDS, Rev. 01
160 gsm Roof Underlay TDS, Rev. 01
180 gsm Roof Underlay TDS, Rev. 01
| Grade / nominal mass | Intended application | Water tightness | Sd maximum (m) | Tensile MD / transverse (N/50 mm) | Controlled source |
|---|---|---|---|---|---|
| 100 g/m² | Wall WRB / housewrap | W1 | 0.012 | 150 / 100 ±15% Measured MD / TD |
KOS-TDS-WM100-2026, Rev. 01 PDF |
| 150 g/m² | Wall WRB / housewrap | W1 | 0.012 | 225 / 150 ±15% Measured MD / TD |
KOS-TDS-WM150-2026, Rev. 01 PDF |
| 120 g/m² | Roof underlay | W1 | 0.015 | 189 / 137 ±15% Typical MD / CD; not guaranteed minima |
KOS-TDS-RM120-2026, Rev. 01 PDF |
| 130 g/m² | Roof underlay | W1 | 0.015 | 200 / 150 ±15% Typical MD / CD; not guaranteed minima |
KOS-TDS-RM130-2026, Rev. 01 PDF |
| 140 g/m² | Roof underlay | W1 | 0.015 | 220 / 160 ±15% Typical MD / CD; not guaranteed minima |
KOS-TDS-RM140-2026, Rev. 01 PDF |
| 160 g/m² | Roof underlay | W1 | 0.015 | 280 / 200 ±15% Typical MD / CD; not guaranteed minima |
KOS-TDS-RM160-2026, Rev. 01 PDF |
| 180 g/m² | Roof underlay | W1 | 0.015 | 315 / 225 ±15% Typical MD / CD; not guaranteed minima |
KOS-TDS-RM180-2026, Rev. 01 PDF |
Water tightness: EN 1928, Method A. Sd: EN ISO 12572. Tensile: EN 12311-2 for the wall grades; EN 12311-1 / EN 13859-1 for the roofing grades. Values from different test methods must not be treated as interchangeable. These TDS do not declare a reaction-to-fire classification.
A wall grade is not automatically a roof underlay, and a breathable underlay is not a vapour barrier. Confirm the current controlled revision and the approved assembly before ordering. Custom grades and roll formats require separate specification approval.
What Is a Waterproof Breathable Membrane?
It is a water-resistive, vapor-permeable layer used within a specified roof or wall assembly. It helps manage incidental external water while permitting water-vapor diffusion. It is not a substitute for the roof covering, cladding, flashing or a separately designed air-control layer.
Roof Underlay or Exterior Wall Housewrap?
- Roof underlay: select for the roof slope, deck, covering, insulation, fixing method and temporary exposure. Review roofing membrane grades and controlled roofing TDS. Synthetic roofing underlayment is a broad category; confirm whether the selected construction is vapor permeable or non-breathable.
- Wall housewrap / WRB: select for the sheathing, cladding, drainage cavity and opening details. Review vapor-permeable housewrap and wall WRB grades. A water-resistive barrier is not automatically a tested air-barrier assembly.
- Facade membrane: open-joint cladding can expose the membrane after completion. Review facade membrane selection and confirm the specific exposure and fire requirements rather than substituting a general wall grade.
Is a Breather Membrane the Same as a Vapor Barrier?
No. A breather membrane permits vapor diffusion; a vapor-control layer limits vapor movement to the degree required by the design. The correct location depends on climate, indoor humidity, insulation and the complete construction. Do not assume the same layer arrangement suits both cold climates and hot-humid air-conditioned buildings.
What Should European and US Buyers Specify?
For European breather membrane and US housewrap / water-resistive barrier inquiries, identify the destination market and intended roof or wall application first. Submit the project specification and required test methods so that product-specific documentation can be reviewed. A standard reference or certificate for one construction does not establish approval of every grade or assembly.
Request Samples, a Controlled TDS and an OEM Quote
Send the application, target grade, roll width and length, order quantity, destination, printing artwork and packing needs. Request the current controlled TDS and applicable reports before sample approval; confirm MOQ, lead time and any custom development in the quotation.
Request a membrane sample and technical quotation or review OEM printing and private-label supply.
Where Waterproof Breathable Membrane Fits
- Provides a water-resistive layer for wall, roof, housewrap and facade assemblies where controlled vapor movement is required.
- Helps the building envelope resist exterior liquid water while retaining a drying path appropriate to the selected wall or roof design.
- Available as roll goods for project supply, OEM branding and private-label packaging after the specification is confirmed.
How to Compare Waterproof Breathable Membrane Grades
- GSM measures mass per unit area, not water resistance or vapor permeance. A heavier membrane is not automatically more breathable or better suited to a particular wall or roof.
- Compare vapor data only with the method, units and test conditions identified. Vapor permeance and equivalent air-layer thickness (Sd) describe vapor transport differently; do not compare bare numbers as if they were the same measurement.
- Use the exact grade, document revision and applicable test report for approval. An SDS explains safe handling and does not certify water resistance, vapor performance or fire classification.
- Roofing, external walls, housewrap and facade applications have different exposure, strength, drainage and vapor-control requirements.
- Compare water resistance, vapor permeance, tensile and tear strength, construction exposure, roll handling and accessory compatibility before selecting a roll construction.
- Installation details including laps, fasteners, flashing, penetrations and drainage must be reviewed as one system.
Waterproof Breathable Membrane Specification Checklist
- Identify the wall, roof, housewrap or facade application before comparing GSM or color.
- Confirm the project requirement for water resistance, vapor permeance, tensile strength, tear strength and construction exposure.
- Set roll width, roll length, color, printing, labels and packing before quotation or sample preparation.
- Review laps, fasteners, flashing, tape and drainage as a continuous installation system.
- Confirm the applicable data sheet, test references and destination-market requirements for the selected product.
- Approve a sample and verify accessory compatibility before bulk production.
Related Technical Resources
Use these application notes with the selected product data sheet and project specification.
Water Resistance + Vapor Permeability
Why durable wall systems need a balanced moisture-management layer.
Five Technical Factors for Housewrap and WRB Performance
A practical framework for comparing WRB and housewrap performance.
How Waterproof Breathable Membranes Work in Walls and Roofs
The principle behind liquid-water protection and controlled vapor diffusion.
