STP ShaliTPO HG FB
A fleece-backed, hot-air-welded TPO membrane that turns leak-prone RCC, metal and timber roofs into one seamless, reflective waterproof sheet, laid dry with no wet coat or curing wait.
What is it?
A 1.2 mm or 1.5 mm single-ply thermoplastic polyolefin (TPO) roofing membrane, non-reinforced and fleece-backed, joined seam-to-seam by hot-air welding into one continuous waterproof sheet.
Where is it used?
RCC, metal-deck and timber terraces, exposed flat roofs, parking podiums and green-roof substrates on housing societies, factories, warehouses and institutional buildings across Delhi NCR and pan-India.
Why use it?
Delivers a factory-controlled, seamless waterproof layer with a Solar Reflectance Index of 100 that keeps roof surfaces cooler, resists UV/ozone/root penetration, and can be inspected and hot-air patched without breaking a monolithic coating.
How is it applied?
Rolled out over a loose ShaliGeoText 300 GSM protection layer, mechanically anchored to the deck, overlapped 75-125 mm and hot-air welded at seams and parapet terminations, then sealed with ShaliSeal PU GG.
About STP ShaliTPO HG FB
STP Limited has been building India’s construction-chemicals catalogue for over eight decades, and ShaliTPO HG FB sits in its single-ply roofing membrane range alongside the reinforced ShaliTPO PR and ShaliTPO GR FB lines. Thermoplastic polyolefin, or TPO, is a polypropylene-and-ethylene-propylene rubber compound that behaves like a thermoplastic at the seams and like rubber everywhere else on the roof. That combination is what lets an installer fuse two membrane sheets together with a stream of hot air rather than an adhesive or a torch, producing a joint that is chemically continuous with the sheet on either side of it, rather than a glued lap that can peel open years later.
The HG FB designation covers the homogeneous, fleece-backed build of the range: a non-reinforced membrane supplied in 1.2 mm and 1.5 mm gauges, factory-toleranced to plus-or-minus 10 percent, and rolled out in 2 m x 20 m sheets that a crew mechanically anchors to the deck rather than bonding wet. On an Indian terrace that means a roof team can lay, weld and hand over a waterproofing layer inside a tight monsoon-adjacent schedule without waiting on cure times, and the reflective white-grey membrane keeps the slab noticeably cooler through a Delhi summer than a dark bituminous or unreflective cementitious finish would.
The technical insight
The number worth reading twice on the STP data sheet is the Solar Reflectance Index of 100, backed by a reflectivity of 0.79 (ASTM C1549) and an emissivity of 0.909 (ASTM C1371) — together these describe a surface that bounces back the large majority of incident solar energy instead of absorbing it into the slab, which is the actual mechanism behind “cool roof” claims rather than just a light-coloured finish. The -40°C brittleness point (ASTM D2137) and the -30°C to 100°C continuous service window matter more in a country with hill-station cold snaps and plains rooftop heat gain than most buyers assume, since a membrane that stiffens or cracks in a cold spell fails exactly where welded seams need to flex. And the “non-reinforced homogeneous” tag is the real technical trade-off in this SKU: strength comes entirely from the TPO compound itself rather than an internal polyester scrim, so breaking and tear values sit lower than STP’s own ShaliTPO PR and GR FB variants — fine for most exposed terraces, but worth checking against foot-traffic and maintenance-access loads before specifying HG FB over the reinforced options.
Where it is used
- Exposed RCC terraces and flat roofs on housing societies and commercial buildings needing a reflective, seamless waterproofing deck
- Retrofit waterproofing over corrugated or standing-seam metal roof sheeting on factories, warehouses and sheds
- Timber and plywood deck waterproofing in low-rise and hill-area construction
- Root-resistant base layer under soil, drainage board and planters on green roofs and podium gardens
- Parking podium decks and terrace walkways, used with a protection or paver layer for durability
- Institutional, IT-park and educational campus roofs targeting lower rooftop surface temperatures
- Below-grade slab waterproofing where a mechanically fixed, weldable sheet suits the detailing
- Re-roofing over ageing bituminous felt or torn EPDM where a dry, weldable overlay avoids tear-off
Key advantages
- Hot-air welded seams fuse into one continuous, monolithic barrier instead of a glued or taped lap joint
- Solar Reflectance Index of 100 with 0.79 reflectivity and 0.909 emissivity gives tested cool-roof performance, not just a light colour
- Chlorine-, plasticizer- and phthalate-free formulation, safer where rainwater is harvested off the same roof
- -40°C brittleness point and -30°C to 100°C continuous service range cope with plains heat and hill-station cold alike
- Root-penetration resistant, so it can sit under a green roof or terrace garden build-up
- Fully mechanical, dry-fixed installation with no wet curing time, so occupied buildings stay in use during the work
- Field-repairable — a torn section can be patched with a fresh weld rather than a full recoat
- Backed by STP’s roughly 85-year manufacturing history and an authorised pan-India applicator network
Limitations & considerations
- Non-reinforced HG-grade construction has lower breaking and tear strength than STP’s own polyester-reinforced ShaliTPO PR/PR FB or glass-reinforced GR FB — not the first choice for heavy foot traffic
- Seam quality depends entirely on applicator skill and hot-air welding equipment; a poorly fused joint is the single biggest failure risk on any TPO roof
- Mechanical fixing means the deck has to accept anchors, which some existing waterproofing warranties or occupied-building conditions may not allow
- As an exposed membrane it can be punctured by dropped tools or sharp debris if left untrafficked without a protection layer
- Upfront material and skilled-labour cost typically runs higher than a cementitious or bituminous coating, even though lifecycle cost can work out lower
- Limited to reflective white/grey finishes for cool-roof performance, so it is not a decorative or coloured terrace surface
Selection & best practice
Start with a clean, dry deck — jet or dry-air off loose grit, oil and debris, then grind the surface smooth, and cast a 75 mm radius PCC/cementitious coving at every wall-to-slab junction so the membrane isn’t asked to turn a sharp corner. Roll out ShaliGeoText 300 GSM loosely as a protection layer with 50 mm overlaps before the membrane goes down. Lay ShaliTPO HG FB and anchor it mechanically, sizing and spacing the fasteners to the wind uplift expected on that roof rather than a standard grid. Overlap adjoining sheets 75-125 mm and weld every seam with hot air only — never adhesive — then probe-test a sample of welds before sign-off, since a visually good seam can still be under-fused. Terminate at the parapet with a termination strip screwed at 300 mm centres, seal the back with a water-lock sealant, and finish the top with ShaliSeal PU GG. Keep welding work out of wind-driven rain and very low temperatures, and keep the crew in gloves and goggles throughout, per STP’s own health and safety note.
Specifications
| System / Chemistry | Non-reinforced, fleece-backed, homogeneous single-ply TPO membrane |
| Nominal Thickness | 1.2 mm or 1.5 mm, ±10% (ASTM D751) |
| Typical Weight | 1.18 kg/m² (1.2 mm) / 1.45 kg/m² (1.5 mm) |
| Breaking Strength (Grab, MD/TD) | 100 lbf min. (1.2 mm) / 110 lbf min. (1.5 mm), ASTM D751 |
| Tearing Strength (Procedure B) | 25 lbf min., both thicknesses, ASTM D751 |
| Brittleness Point / Service Range | -40°C (ASTM D2137); continuous service -30°C to 100°C |
| Water Vapour Permeance | 0.10 perms max. (ASTM E96, Procedure B) |
| Solar Reflectance Index | SRI 100; Reflectivity 0.79 (ASTM C1549); Emissivity 0.909 (ASTM C1371) |
| Pack Size | Rolls 2 m width x 20 m length; 1.2 mm & 1.5 mm gauges |
Industry use cases
Residential / Group Housing (Delhi NCR)
Retrofitting leak-prone RCC terraces on multi-storey societies with a mechanically fixed, weldable membrane that avoids the multi-day wet cure of liquid coatings in a tight monsoon-adjacent window.
Industrial / Warehousing
Waterproofing large-span metal roof sheets and skylights on factories and warehouses, where the reflective, lightweight membrane also cuts internal heat gain in uninsulated sheds.
Institutional / Educational Campuses
Cool-roof retrofits aimed at lower rooftop surface temperatures and sustainability scoring on schools, colleges and office campuses.
Green Roof / Landscaped Terraces
Root-resistant base membrane under drainage boards, soil and planters on podium gardens and terrace landscaping.
Commercial / IT Parks
Large flat-roof podiums and parking decks needing a fast, field-weldable waterproofing system with minimal shutdown time on occupied buildings.
Frequently asked questions
What does the “FB” in ShaliTPO HG FB stand for, and how is it different from plain ShaliTPO HG?
Can ShaliTPO HG FB be walked on as a regular terrace surface?
Does it need a primer or bonding coat before laying?
How much faster is this than a conventional liquid waterproofing coat?
What warranty does Space Arc offer on a ShaliTPO HG FB installation?
Is this membrane suitable for a green roof or terrace garden?
How we position STP ShaliTPO HG FB
Within STP’s own ShaliTPO range, HG FB is the reflective, non-reinforced entry point — step up to ShaliTPO PR or PR FB when a project needs polyester-scrim reinforcement for higher tear and puncture resistance, or to ShaliTPO GR FB where glass reinforcement and dimensional stability matter more than cost. It’s typically specified alongside ShaliGeoText 300 GSM as the loose protection layer underneath and ShaliSeal PU GG for parapet and termination detailing, both from the same STP system. Outside the STP catalogue, specifiers comparing single-ply TPO against other chemistries often shortlist Fosroc’s Proofex bituminous membrane range or EPDM alternatives, but those are torch-applied or lap-adhered systems rather than hot-air-welded TPO, so the comparison is really about installation method and roof-life trade-offs as much as price.
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