Bradford Thermoseal™ 733MD / 753HD Roof Sarking
Bradford Thermoseal 733MD / 753HD installs beneath tiles or metal sheets as a tough, reflective vapour-barrier layer. It helps keep out wind-driven rain, dust and embers and assists with summer comfort.
Choose 733MD for smooth, everyday handling or upgrade to 753HD where extra durability and/or an outward-facing antiglare surface is needed on exposed or busy sites. Thermoseal can also be used as a facing on Bradford Glasswool Building Blanket, either adhered or laid separately.
Suitable for use across BAL regions in a compliant roof system and backed by CSR Bradford technical support and warranty.
Features and Benefits
Bradford Thermoseal works like a protective second skin under the roof, limiting water entry paths and directing incidental moisture to the gutter to help prevent leaks and staining. It creates a tidy underlay that speeds dry-in so internal trades can start sooner. The reflective face assists with heat control in hot weather, while the reinforced membrane lays flat, tapes neatly and stands up to handling for a clean, consistent finish.
Key Features
Bushfire protection
Suitable for BAL 12.5-FZ when installed to specification
Blocks ember entry
Helps seal vulnerable roof edges and junctions to keep embers and flames out
Heat relief
Helps improve summer comfort and supports energy efficiency
Easy to install
Tough, tear-resistant membrane that rolls out quickly for a neat finish under tile and metal roofs
Range
Two duty levels to match site conditions and handling needs.
Thermoseal 733MD (Medium Duty)
Vapour-barrier, paper-based reflective sarking with a smooth internal finish; reflective foil inward, antiglare outward. Suitable for tile or metal roofs and metal-clad walls.
Thermoseal 753HD (Heavy Duty)
Vapour-barrier, heavier-reinforced reflective sarking; reflective foil inward, antiglare outward. Suitable for tile or metal roofs where extra puncture resistance and reduced wind flap are required.
Note: Reflective sarking products are typically vapour barriers and may not be suitable in colder climates where condensation presents a risk - always follow the NCC condensation management guidelines and consider the Enviroseal® range of vapour permeable products if in doubt.
Technical Specifications
Bradford Thermoseal 733 MD/753HD
| Product Name | Duty | Dimensions | m2 per pack | Product Code |
Thermoseal 733 MD | Medium Duty | 1350mm x 30m | 40.5 | 25489 |
| Medium Duty | 1350mm x 60m | 81 | 15061 | |
| Thermoseal 753 HD | Heavy Duty | 1350mm x 60m | 81 | 15091 |
Use Thermoseal 733MD / 753HD wherever a strong, reflective sarking layer is needed to boost weather defence, bushfire resilience and installation efficiency.
- Under tile or metal roofing in residential or light commercial projects
- When to install: during the roof stage before the roof covering is laid. Typically draped over rafters or trusses for tiles, or across purlins for metal, and under battens. Lap joints should be detailed to drain to the gutter
- Exposed sites where extra protection is needed for high-wind or debris-prone areas as part of a compliant roof system
Note: Reflective sarking is typically a vapour barrier and may not suit colder climates where condensation risk is higher. Always follow NCC condensation management guidance and consider the Enviroseal vapour-permeable range if unsure.
Performance Guaranteed
Australian Made
Licensed by Australian Made Campaign Limited to use the Australian Made logo.
Bradford 90 Years
Bradford has been trusted for over 90 years, with products engineered to deliver superior performance in insulation and ventilation systems.
Sensitive Choice
Certified by an independent expert panel to meet the health and safety standards of the Sensitive Choice program for asthma and allergy friendly products.
ISO 9001
Meets the ISO 9001 standards for quality management through independent verification.
