GNR Roofing Services
Sarnafil Roofing Products
Sarnafil, part of the Sika Group, is a globally recognised manufacturer of high-performance roofing solutions. Specialising in single ply membranes, Sarnafil has built a reputation for durability, quality, and sustainability in roofing systems. These products are ideally suited for flat and low-pitched roof applications in both new builds and refurbishment projects.
Sarnafil provides a comprehensive range of roofing solutions including:
- Single Ply Membranes: High-performance waterproofing systems with exceptional longevity and weather resistance.
- Complete Roofing Systems: Including insulation, vapor control layers, and accessories for a full system warranty.
- Sustainability & Certification: Products that meet the highest environmental and performance standards (BREEAM, LEED, ISO certified).
Sarnafil ® Single Ply
Sarnafil Overview
Sarnafil is a brand of single-ply flat roofing membranes manufactured by Sika. Sika’s website describes Sarnafil as a “high-performance roofing solution” for various applications, including commercial and domestic flat roofs.
Sarnafil Single Ply Membranes Range
Sarnafil offers a variety of single ply roofing membranes tailored to different requirements:
1. Sarnafil® G410 – Fleece-backed PVC Membrane
- Ideal for adhered and mechanically fixed systems.
- High resistance to UV, weathering, and fire.
- Available in a range of colours.
2. Sarnafil® G476 – Waterproofing Membrane
- Designed specifically for green roofs and below-ground waterproofing.
- Root-resistant, durable under soil and plant systems.
3. Sarnafil® S327 – Reinforced PVC Membrane
- Typically used in mechanically fastened systems.
- Excellent wind uplift resistance and puncture resistance.
4. Sarnafil® T – Polyolefin Membranes
- Non-PVC alternative offering excellent environmental credentials.
- Suitable for projects requiring low environmental impact and recyclability.
These membranes can be used in:
- Warm, cold, or inverted roofs
- Green roofs
- Ballasted, adhered, or mechanically fastened systems
GNR Roofing – Leading Sarnafil and Sika Liquid Plastics Installer
GNR Roofing is a trusted and leading supplier and installer of Sarnafil Single Ply Membranes and Sika Liquid Plastics systems. With decades of industry experience, GNR Roofing is recognised for its expert knowledge, quality workmanship, and project delivery capabilities across the UK.
Why Choose GNR Roofing:
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Certified Sarnafil Installers: Trained and approved to install Sarnafil systems to the highest standards.
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Sika Liquid Plastics Specialists: Offering cold-applied waterproofing solutions for complex detailing and refurbishments.
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Full System Warranty: Installations eligible for comprehensive warranties backed by Sika.
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Sustainable & Safe: All work carried out with strict compliance to H&S, environmental and building regulations.
Capability to Deliver Projects at Any Scale
Whether it’s a domestic property, a commercial development, or a large-scale industrial roofing project, GNR Roofing has the resources, technical expertise, and capacity to manage projects of any scale using Sarnafil’s industry-leading systems.
From initial design consultation to final installation and certification, GNR Roofing ensures every project is completed to the highest professional standard, on time and within budget.
Flat Roofing
Single
Single layer roof membranes by GNR.
Ply
Highly durable modern roofing solutions.
Roofing
Stand alone or as part of a package.
Uses of Sarnafil
Sarnafil is a brand of high-performance single-ply roofing membranes manufactured by Sika. These membranes are made primarily of polyvinyl chloride (PVC) and are known for their durability, weather resistance, and long service life. They are reinforced with fiberglass or polyester for additional strength and are used extensively in both new builds and refurbishments.
Commercial Roofing Applications
Sarnafil membranes are widely used in commercial roofing due to their robust performance in demanding environments. Key applications include:
Flat and Low-Slope Roofs
- Ideal for warehouses, factories, and retail units where large roof spans are common.
- Membranes offer excellent waterproofing and thermal performance.
Green Roof Systems
- Compatible with intensive and extensive green roofs.
- Provide root resistance and can withstand the added load and moisture conditions.
Solar Roofs
- Designed to integrate with solar panel systems using non-penetrative mounting options.
Public Sector Buildings
- Schools, hospitals, and government offices often choose Sarnafil for its proven longevity and low maintenance.
Airports and Stadiums
Used in complex roof geometries due to its weldable seams and flexibility.
Get a QuotationDomestic Roofing Applications
Sarnafil is also used in high-end and bespoke residential roofing projects, typically where long life expectancy and low maintenance are desired:
Flat Roof Extensions
- Common in modern home extensions and garden buildings.
- Offers a sleek, unobtrusive look with long-term durability.
Balconies and Terraces
- Provides a watertight seal beneath tiles or decking.
- Often used in conjunction with insulation systems for thermal efficiency.
Eco-Friendly Homes
- Can be used in green or living roofs on domestic builds.
- Suitable for sustainable construction projects.
Heritage and Custom Designs
- Available in various colors and textures (e.g., lead grey) for visual compatibility with traditional styles.
Sarnafil membranes are valued for their 40+ year track record, BBA certification, and performance under extreme weather, making them a trusted solution across sectors.
Sarnafil Vs GRP
Material Overview
Sarnafil (PVC Single-Ply Membrane)
- A high-performance, thermoplastic roofing membrane developed by Sika.
- Used globally for over 40 years in commercial and domestic applications.
- Fully adhered or mechanically fixed systems with heat-welded seams.
GRP (Glass Reinforced Plastic)
- Also known as fibreglass roofing.
- Typically installed as a cold-applied, liquid-based system with a topcoat.
- Popular in domestic flat roofing due to ease of installation and low upfront cost.
Benefits of Sarnafil
| Feature | Sarnafil | GRP (Fibreglass) |
|---|---|---|
| Longevity | 40+ years proven life span (BBA certified) | Often fails within 7–10 years; many within 5–7 years |
| Seam Strength | Hot-air welded seams create a monolithic bond | Seams/joints are vulnerable to cracking or de-bonding |
| Flexibility | Remains flexible in cold and heat; accommodates movement | Brittle over time, prone to stress cracking |
| UV Resistance | Excellent, retains integrity over decades | Topcoat deteriorates, leading to water ingress |
| Installation Quality | Installed by certified contractors only | Widely variable quality, often DIY or low-cost installers |
| Roof Shapes | Easily adapts to complex geometries | Best suited for simple, small, flat surfaces |
| Maintenance | Minimal required | Prone to cracking, blistering, and pooling issues |
GRP Failure Rates
GRP High Failure Rates
Common Issues with GRP:
- Cracking due to thermal movement and structural flexing.
- Topcoat degradation from UV exposure, reducing waterproofing ability.
- Poor workmanship: many GRP roofs are installed without proper substrate prep or detailing, leading to failure.
- Lack of flexibility means poor performance on larger or more complex roofs.
Documented Failure Rate:
- GRP roofs frequently fail within 5–7 years, especially when installed by non-specialists or used in unsuitable applications like large flat roofs or high-movement areas.
While GRP roofing can be cost-effective for very small, low-risk applications, Sarnafil membranes offer vastly superior performance, lifespan, and reliability — especially critical in both commercial settings and long-term residential builds.
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Sarnafil ® Superiority
When selecting a flat or low-pitched roofing system, long-term performance, durability, and low maintenance should be at the forefront of decision-making. Compared to alternatives like GRP and EPDM, Sarnafil consistently stands out as the superior option across all key metrics.
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Versus GRP: Sarnafil’s flexibility, welded seams, and certified installation ensure decades of watertight protection — far exceeding GRP’s typical 5–7 year failure window caused by brittleness, cracking, and poor topcoat longevity.
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Versus EPDM (rubber): While EPDM offers some durability, it lacks Sarnafil’s heat-welded seam strength and is more prone to shrinkage, adhesive failure, and punctures, especially on complex or detailed roofs.
Sarnafil’s 40+ year track record, extensive certifications, and proven performance in both domestic and commercial settings make it the gold standard in flat roofing systems. Whether you’re protecting a family home, public building, or industrial facility, Sarnafil provides a reliable, aesthetically versatile, and future-proof solution.
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