STP ShaliTPO GR FB
A glass-scrim reinforced, hot-air welded TPO membrane engineered for exposed metal, timber and RCC roofs that need genuine watertightness, UV stability and a cooler roof surface.
What is it?
A 1.2 mm or 1.5 mm single-ply thermoplastic polyolefin (TPO) roofing membrane, reinforced with a glass scrim and backed with a fleece layer, supplied in 2 m x 20 m rolls that are mechanically fixed and hot-air welded at the seams.
Where is it used?
Exposed flat and low-slope roofs — metal deck, wooden and RCC terraces — on factory sheds, warehouses, cold storages, commercial buildings, and green or podium roofs where root resistance matters.
Why use it?
It pairs a genuinely watertight, factory-controlled membrane with high UV/ozone resistance, a solar-reflective cool-roof surface, and a mechanically fixed, fully hot-air welded seam system that doesn’t rely on a torch or adhesive lap.
How is it applied?
Mechanically anchored over a loosely laid ShaliGeoText 300 GSM separation layer, laid with 75-125 mm overlaps and continuously hot-air welded at seams and terminations, then finished at parapets with a screwed termination strip sealed underneath and capped with ShaliSeal PU GG.
About STP ShaliTPO GR FB
ShaliTPO GR FB is STP Limited’s glass-scrim reinforced, fleece-backed member of the ShaliTPO single-ply roofing range. Unlike a bituminous felt that’s torch-applied or an EPDM sheet that relies on adhesive-bonded or taped laps, this is a thermoplastic polyolefin sheet whose seams are hot-air welded into a single continuous, homogeneous joint — there’s no adhesive line to fail years down the line. The glass scrim sandwiched inside the sheet gives it dimensional stability under heat cycling (movement stays within ±0.5% after six hours at 80°C), while the fleece backing lets it sit and mechanically fix cleanly over a loosely laid separation layer instead of being fully bonded to the deck.
In practice that makes it a roofing membrane rather than a wet-area waterproofing coat — it’s specified for exposed metal, wooden and RCC terraces where the sheet stays visible and load-bearing through sun, rain and foot traffic, not buried under screed. Its light, reflective face knocks down roof surface temperature (a real consideration on Delhi NCR’s summer RCC terraces), it resists root penetration so it can go under a landscaped roof garden, and its chemical and ozone resistance suits cold-storage and industrial-shed roofs where bituminous membranes degrade faster. Space Arc supplies and installs it as an STP-authorised applicator, with hot-air welding done and peel-tested on site rather than left to guesswork.
The technical insight
The “GR” in the name is the detail worth understanding before you specify: STP’s ShaliTPO range comes in HG (homogeneous, unreinforced), PR (polyester-reinforced) and GR (glass-scrim reinforced) builds. Glass scrim gives the sheet the best dimensional stability of the three — it won’t creep or shrink under repeated thermal cycling the way a purely homogeneous sheet can, which is why STP’s own data sheet targets ShaliTPO GR FB at exposed, temperature-swinging roofs rather than protected or below-ground use. The trade-off is that glass scrim is stiffer and less forgiving around tight details than the polyester-reinforced PR FB, so roof geometries with heavy penetration counts, upstands and awkward flashing often suit PR FB better, while large, relatively flat industrial and RCC roof fields play to GR FB’s dimensional stability and lower material cost per welded square metre.
Where it is used
- Exposed RCC terrace waterproofing on commercial, institutional and residential-complex roofs
- Metal-sheeted factory, warehouse and industrial-shed roof retrofits
- Cold storage and food/pharma facility roofs needing chemical and root resistance
- Green roofs, roof gardens and podium decks where root resistance is required (DIN 4062)
- Wooden roof decks and sloped timber terraces
- Re-roofing overlays on ageing bituminous membranes without a full tear-off
- Basement or plaza deck waterproofing under paver or ballast finishes
- Fire-sensitive sites where open-flame torch application is restricted
Key advantages
- Hot-air welded seams form a single homogeneous joint instead of an adhesive lap, which is usually where membrane failures start
- High puncture resistance (300 mm / 600 mm per DIN 16726, by thickness) and tearing strength (135 N / 165 N) for site handling and foot traffic
- Chlorine-free, plasticizer-free and phthalate-free — doesn’t leach or embrittle the way plasticized sheet can over time
- High solar reflectivity keeps roof surface temperatures down, a genuine cool-roof benefit through Indian summers
- Root-resistant to DIN 4062, so it’s usable under landscaped or green-roof buildups without a separate root barrier
- Rated for continuous service from -30°C to 100°C without cracking or embrittlement
- No open flame needed for installation — safer than torch-applied bitumen near insulation, timber decking or occupied buildings
- Easy to repair — a damaged patch can be hot-air welded on rather than requiring membrane replacement
Limitations & considerations
- Mechanically fastened installation means anchor spacing must be engineered for the site’s wind-uplift zone — it isn’t a loose-lay-and-forget product
- Seam quality depends entirely on the welding operator; an untrained crew with an uncalibrated hot-air gun is the single biggest cause of TPO site failures generally
- It’s an exposed roofing membrane, not a below-grade tanking or wet-area coating — don’t specify it where a liquid-applied or crystalline system is actually needed
- STP’s published data sheet covers two thicknesses (1.2 mm and 1.5 mm) — very high-abrasion or ballasted roofs may need a heavier single-ply range
- Needs a properly sloped, structurally sound deck; ponding water on a flat roof will eventually find any weak seam, membrane or not
- Project-specific system warranty terms aren’t published on the public data sheet and need to be confirmed with STP or Space Arc at quotation stage
Selection & best practice
Lay a loose ShaliGeoText 300 GSM separation sheet first with 50 mm overlaps, then mechanically anchor ShaliTPO GR FB with fastener spacing sized to the site’s actual wind-uplift calculation rather than a generic pattern. Keep overlaps to 75-125 mm and weld every seam with a hot-air gun only — this membrane isn’t designed for adhesive or solvent welding. Terminate at parapets with STP’s termination strip screwed at 300 mm c/c, sealed underneath with a water-lock sealant and capped with ShaliSeal PU GG. Probe- or peel-test every welded seam as you go rather than only at handover, and confirm your applicator carries STP welding training — Space Arc’s site crews do.
Specifications
| Nominal Thickness | 1.2 mm or 1.5 mm (±10%), EN 1849-2 |
| Specific Weight | 1.4 kg/m² (1.2 mm) / 1.7 kg/m² (1.5 mm), EN 1849-2 |
| Tensile Strength | 9 MPa min (1.2 mm) / 10 MPa min (1.5 mm), EN 12311-2 |
| Elongation at Break | 200% min, EN 12311-2 |
| Tearing Strength | 135 N min (1.2 mm) / 165 N min (1.5 mm), EN 12310-2 |
| Cold Bending | ≤ -40°C, EN 495-5 |
| Hydrostatic Pressure Resistance | Waterproof at 5 bar for 6 hrs, EN 1928 Method B |
| Peel Resistance of Welded Joints | 150 N/50mm min, EN 12316-2 |
| Roll Size | 2 m width x 20 m length |
Industry use cases
Warehousing & Logistics
Retrofitting a leaking metal-sheeted warehouse roof with a mechanically fixed, hot-air welded membrane instead of a full re-roof.
Cold Storage & Food Processing
Root- and chemical-resistant RCC roof waterproofing where an open-flame torch can’t be used near insulated panels.
Green Roofs & Podium Decks
Root-resistant base membrane under a landscaped roof garden or paver-finished podium deck.
Institutional & Educational Buildings
Exposed terrace waterproofing where fire-safety rules restrict torch-applied bituminous membranes.
Industrial Re-roofing
Overlaying an ageing bituminous roof membrane to extend service life without a costly tear-off.
Frequently asked questions
How is ShaliTPO GR FB different from ShaliTPO PR FB and ShaliTPO HG FB?
Does installation need a torch, like bituminous membranes?
Can it be used under a roof garden or planted podium?
What thickness and roll size should we order?
Is it suitable for a leaking RCC terrace we want to waterproof without breaking the existing structure?
Who actually welds and commissions this on-site?
How we position STP ShaliTPO GR FB
ShaliTPO GR FB sits inside STP’s own single-ply family alongside ShaliTPO PR FB (polyester-reinforced, better suited to detail-heavy roofs) and ShaliTPO HG FB (unreinforced, for simpler formats) — Space Arc typically pairs it with ShaliGeoText 300 as the separation layer underneath and ShaliSeal PU GG at parapet terminations, all sourced through the same STP order. Outside the STP range, the closest thing to a direct technology competitor is Sika’s Sarnafil/Sikaplan single-ply TPO and PVC membranes, which follow a similar mechanically-fixed, hot-air-welded logic. Fosroc doesn’t carry a comparable single-ply TPO roofing membrane in its India catalogue; its nearest exposed-roof waterproofing option is the torch-applied modified-bitumen Proofex Torchseal range, which a specifier might still choose over ShaliTPO GR FB on a smaller roof where torch application isn’t restricted and a bituminous system’s lower material cost matters more than TPO’s weld-seam, UV and root-resistance advantages.
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