Sika Sarnafil G 410-15 L
A 1.5 mm glass-fleece reinforced PVC single-ply membrane built for the fiddly detailing work — upstands, corners, drains and penetrations — on exposed and ballasted flat roofs.
What is it?
A 1.5 mm thick, multi-layer PVC roof waterproofing sheet with a glass non-woven (glass fleece) inlay, lacquer-coated and hot-air weldable — designed as the detailing membrane within a Sarnafil single-ply roof system.
Where is it used?
Exposed flat roofs, green and utility roofs, inverted and gravel-ballasted decks — specifically at upstands, parapets, corners, drains, scuppers and pipe penetrations where a flexible detailing sheet is needed.
Why use it?
It welds to itself and to the field membrane to form a homogeneous, root-resistant, UV-stable waterproofing skin with no open flame, and carries CE marking to EN 13956.
How is it applied?
Rolled out over a clean, compatible substrate and heat-welded at the overlaps with hot-air equipment at a minimum +600 degrees C, giving a continuous seam at least 20 mm wide that is then probe-tested.
About Sika Sarnafil G 410-15 L
Sarnafil G 410-15 L is Sika’s polymeric PVC detailing membrane, part of the long-established Sarnafil single-ply roofing family. At 1.5 mm thick, it is a multi-layer sheet based on plasticised polyvinyl chloride with a glass non-woven inlay running through it. That glass fleece is what gives the membrane its dimensional stability — it holds its shape and resists shrinkage, which matters when you are dressing a sheet tightly around a drain body or up a parapet. The top surface carries a lacquer coating that keeps dirt pick-up down and helps the white finish stay reflective through years of exposure, while the underside is dark grey. Ultraviolet stabilisers are built into the compound to EN 13956, so the sheet is formulated to sit fully exposed to sun and weather rather than being buried under a screed.\n\nIn practice this is the sheet a roofing crew reaches for at the tricky parts of an installation. The main field of the roof might be laid in Sarnafil S 327 L or the felt-backed G 410 L, but corners, internal and external angles, pipe collars and gutter details are where a thinner, more workable membrane earns its place. Because everything is joined by hot-air welding — no torches, no adhesive lines to fail at the seam — a competent applicator can build a monolithic waterproofing layer where the detailing membrane and the field membrane become effectively one continuous skin. It is a system product, not a standalone coating, and it is meant to be installed by Sika-trained contractors who understand the welding discipline behind it.
The technical insight
The membrane works because thermoplastic PVC can be re-melted and fused. When hot air at 600 degrees C or more is driven into the overlap, the two facing surfaces soften and, under roller pressure, flow together and re-solidify as a single mass — a true weld, not a glued lap. That is why single-ply roofs seal at the seam rather than fail there: the joint has the same chemistry and roughly the same strength as the sheet itself. The glass non-woven inlay does the structural job the PVC alone cannot, restraining thermal and dimensional movement (dimensional change stays within about 0.2 percent) so the sheet does not creep or pull away from a welded detail over seasons of heating and cooling. Meanwhile the lacquered white top surface reflects solar energy — a solar reflectance of 0.80 and an initial SRI of 106 — keeping the roof and the building beneath it cooler, and the sheet’s high water-vapour resistance (µ = 15,000) stops it acting as a path for moisture. Root resistance to EN 13948 rounds it out for green-roof duty.
Where it is used
- Detailing and flashing at parapets, upstands and skirtings on exposed PVC single-ply roofs
- Sealing around roof penetrations — vent pipes, cable entries, rooflight kerbs and plant supports
- Forming welded collars at roof drains, outlets and scuppers
- Internal and external corner detailing where the field membrane cannot be dressed cleanly
- Green and landscaped roofs requiring root-resistant, root-penetration-proof detailing
- Inverted, ballasted and gravel-loaded roofs (used with Sarnafil G 476 as the field sheet)
- Utility and podium decks over commercial, office and logistics buildings
- Refurbishment and re-roofing detailing over compatible, prepared substrates
Key advantages
- Hot-air weldable seams create a homogeneous, monolithic joint that seals as strongly as the sheet
- No open flame or torch needed — safer detailing near insulation, timber and occupied buildings
- Glass fleece inlay gives high dimensional stability, so details hold their shape over thermal cycles
- Lacquer-coated white surface stays cleaner and delivers cool-roof reflectance (SR 0.80, SRI 106)
- Root-resistant to EN 13948, making it suitable for green and landscaped roofs
- CE marked with a Declaration of Performance to EN 13956 for specification compliance
- Proven PVC single-ply track record over decades of exposed roofing service
- Contributes to LEED v4 material and sourcing credits on green-building projects
Limitations & considerations
- Installation is restricted to Sika-trained and approved contractors — it is not a DIY or general-labour product
- Must be kept away from bitumen, tar, oil, solvents, EPS, XPS, PUR, PIR and phenolic foam, which attack PVC
- Cannot be applied to wet, damp or unclean substrates; the surface must be uniform and free of sharp protrusions
- Reaction to fire is Class E — where a higher fire class is specified, this membrane will not meet it on its own
- Some ancillary adhesives, cleaners and solvents are limited to use above +5 degrees C, constraining cold-weather work
- As a 1.5 mm detailing membrane it is not intended as the main mechanically-fastened field sheet on large roof areas
Selection & best practice
Start with the substrate: it must be smooth, clean, dry and free of burrs, and separated from any incompatible material (bitumen, insulation foams, solvents) by an effective separation layer, since direct contact accelerates ageing. Metal surfaces should be degreased with Sarna Cleaner before any adhesive. Weld overlaps only with controlled hot-air equipment capable of a minimum +600 degrees C — Leister Triac for manual work, Sarnamatic 681 for automatic runs — and establish temperature, speed and pressure with trial welds on site first, because ambient conditions change the settings. Keep the effective welded width at 20 mm or more, then probe every seam with a rounded screwdriver and re-weld any imperfection. Store rolls flat, unopened, in dry conditions between +5 and +30 degrees C, never stacking pallets, and use within the five-year shelf life. Below +5 degrees C ambient, follow the national safety measures Sika requires.
Specifications
| Membrane type | Multi-layer PVC single-ply roof membrane, glass non-woven inlay |
| Thickness | 1.5 mm (EN 1849-2) |
| Roll size | 20.00 m length x 2.00 m width; approx. 78 kg per roll |
| Mass per unit area | 1.89 kg/m2 |
| Colour | Top surface white (matt, other colours on request); underside dark grey |
| Tensile strength | >= 8.5 N/mm2, longitudinal and transversal (EN 12311-2) |
| Elongation | >= 180% (EN 12311-2) |
| Tear strength | >= 50 N/mm (GB/T529) |
| Welding / overlap | Hot-air weld at min. +600 degrees C; effective overlap min. 20 mm |
| Solar reflectance / SRI | 0.80 solar reflectance; SRI 106 (white, initial) |
| Reaction to fire | Class E (EN 13501-1) |
| Standard | CE marked, DoP to EN 13956 |
Industry use cases
Commercial and logistics roofs
Exposed flat roofs on offices, malls and warehouses use G 410-15 L to detail parapets, kerbs and penetrations within a white cool-roof Sarnafil system.
Green and landscaped roofs
Root-resistant to EN 13948, it seals drains and upstands on planted and utility decks where soil and irrigation sit directly over the waterproofing.
Inverted and ballasted decks
On gravel-loaded and inverted roofs — typically over Sarnafil G 476 field sheet — it forms welded collars and corners that stay intact under ballast movement.
Podium and terrace slabs
Provides reliable detailing at outlets and junctions on podium decks and terraces where reflective, low-maintenance PVC roofing is specified.
Re-roofing and refurbishment
Used to rebuild watertight details over prepared, compatible substrates when older exposed roofs are overlaid with a single-ply system.
Frequently asked questions
Is Sarnafil G 410-15 L the main roof membrane or a detailing sheet?
How are the seams sealed — is any flame involved?
Can it be left fully exposed to the sun?
Is it suitable for green roofs?
What surfaces and materials must it be kept away from?
Who is allowed to install it?
How we position Sika Sarnafil G 410-15 L
Sarnafil G 410-15 L is a detailing membrane and works as part of a full Sika single-ply system rather than on its own. For the main roof field, pair it with Sarnafil S 327 L or the felt-backed Sarnafil G 410 L Felt on exposed roofs, or with Sarnafil G 476 on ballasted, green and inverted roofs. Complete the installation with the matching Sika ancillaries — Sarnacol 2170 contact adhesive, Sarna Cleaner for degreasing metal, Sarnabar for perimeter fixing, and Sarnamatic 681 or a Leister Triac for welding. Space Arc, as an authorised Sika distributor across Delhi NCR and pan-India, can supply the whole Sarnafil roof build-up together with the correct welding and detailing accessories. Because this is a thermoplastic PVC single-ply system — a fundamentally different technology from cementitious and liquid-applied waterproofing — it does not have a like-for-like Fosroc equivalent; where a project instead calls for liquid membrane or crystalline waterproofing on concrete decks, our Fosroc range (Brushbond and Proofex lines) covers that separate approach.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.