Fosroc Proofex Torchseal 3PV
Polyester-reinforced, APP-modified bitumen torch-applied membrane for durable below- and above-ground waterproofing.
What is it?
A prefabricated, torch-applied waterproofing membrane made from APP-modified bitumen reinforced with a non-woven polyester core, supplied in rolls and fully bonded to the substrate by flame.
Where is it used?
Concrete roof and floor slabs, basement and retaining-wall tanking, car-park decks, podiums, tunnels and subways across building and infrastructure projects.
Why use it?
Delivers a seamless, high-puncture-resistance bituminous barrier with proven heat ageing and chemical resistance, ideal for India’s heat, monsoon loads and aggressive ground water.
How is it applied?
Prime the prepared concrete with Torchseal Primer, then unroll and torch-bond the membrane with full laps, sealing all overlaps and details before protection screed.
About Fosroc Proofex Torchseal 3PV
Fosroc Proofex Torchseal 3PV is a factory-made, torch-applied (heat-bonded) waterproofing membrane built around APP (atactic polypropylene) modified bitumen reinforced with a non-woven polyester carrier. The polyester core — the reason for the “3PV” / polyester designation — is rot-proof and dimensionally stable, giving the sheet its tensile strength, elongation and high resistance to piercing and stress. The “3” indicates the nominal 3 mm membrane thickness; a heavier 4 mm grade exists in the same family for higher mechanical or chemical duty. Supplied in rolls (typically 10 m long x 1 m wide), the membrane is unrolled over a primed concrete substrate and bonded by melting its underside with an LPG torch, producing a continuous, fully-adhered barrier with no field seams that rely on adhesives. For Indian construction — where roofs bake under intense summer sun, basements sit in fluctuating water tables, and structures must survive heavy monsoon loading — a torch-on APP system like Proofex Torchseal 3PV is a workhorse specification. As an authorised Fosroc distributor serving Delhi NCR and pan-India, Space Arc Engineering supplies Proofex Torchseal 3PV alongside its companion primer and protection products so that contractors receive a complete, warranty-friendly waterproofing package rather than mismatched components.
The technical insight
The performance of Proofex Torchseal 3PV comes from the marriage of two materials. APP-modified bitumen raises the bitumen’s softening point to around 150°C (ASTM D36) and improves UV and heat-ageing stability versus plain oxidised bitumen, while keeping the sheet flexible to roughly -5°C cold-bend (DIN 52123) — important for thermal cycling. The non-woven polyester carrier (around 180 g/m2 in this Torchseal family) carries the load: the published Torchseal data shows tensile strength of the order of 750 N/5cm longitudinal and 550 N/5cm transverse with elongation near 40-50%, so the sheet bridges minor substrate movement and resists puncture from backfill or foot traffic. Because the membrane is torch-fused, the bond is thermo-mechanical — the molten bitumen wets into the primed substrate and into the overlaps, creating monolithic laps. This makes correct flame control the single biggest workmanship variable: under-heating starves the bond, over-heating degrades the bitumen and burns through the carrier. Always read the current India-region Fosroc TDS for the exact figures applicable to your batch and grade.
Where it is used
- Waterproofing of concrete roof and floor slabs
- Basement and below-ground tanking on walls and rafts
- Car-park deck and podium slab waterproofing
- Concrete retaining structures subject to ground-water pressure
- Tunnels, subways and other buried civil-engineering structures
- Bridge decks and approach slabs (with suitable protection)
- Wet areas and terraces where a robust bituminous barrier is required
Key advantages
- Seamless, fully-bonded barrier — torch fusion eliminates reliance on field adhesives
- Non-woven polyester core gives high tensile strength and excellent puncture/stress resistance
- APP modification provides strong heat-ageing and UV stability, suited to Indian summer roof temperatures
- Good flexibility and elongation to accommodate thermal movement and minor cracking
- Prefabricated to a controlled, uniform thickness — more consistent than site-mixed coatings
- Resistant to many aggressive ground-water salts encountered in below-ground work
- Fast to install over large areas by trained torch applicators
- Compatible with the Fosroc Torchseal primer and protection system for a single-source warranty
Limitations & considerations
- Requires open-flame (LPG torch) application — needs trained applicators and strict fire-safety controls; unsuitable near combustibles or in enclosed unventilated spaces without precautions
- Not a self-applied product; quality is highly workmanship-dependent on flame control and lap sealing
- Bituminous and dark-coloured — needs UV-protective screed, tiles or coating where permanently exposed
- Substrate must be sound, dry and primed; will not bond reliably over damp, dusty or laitance-covered concrete
- Exposed bitumen can soften at very high surface temperatures, so trafficked/exposed areas need a protection layer
- Overlaps and upstand/penetration detailing must be fully torch-sealed — cold or unsealed laps are the common failure point
- Not intended as a finished wearing surface; a screed or topping is required for foot or vehicle traffic
Selection & best practice
Achieve a sound, clean, dry concrete substrate (laitance and sharp protrusions removed, fillets at internal corners). Apply Fosroc Torchseal Primer at roughly 0.2-0.8 L/m2 and allow it to dry tack-free. Set out rolls to give a minimum 100 mm side lap and 150 mm end lap, staggering end laps. Torch the underside of the roll and the substrate together, advancing steadily so a small bead of molten bitumen flows ahead of the roll at the lap — this visible bead confirms a fused seam. Dress all upstands, drains and pipe penetrations with cut pieces and seal them fully. Flood-test horizontal areas for 24-48 hours before covering, then protect the membrane promptly with a screed, board or geotextile-plus-backfill so it is never left exposed to UV or trade damage. Maintain strict fire-watch and ventilation, and always follow the current India-region Fosroc method statement and TDS.
Specifications
| Product type | Prefabricated torch-applied waterproofing membrane |
| Bitumen chemistry | APP (atactic polypropylene) modified bitumen |
| Reinforcement | Non-woven polyester core (Torchseal family approx. 180 g/m2) |
| Nominal thickness | 3 mm (4 mm grade also available in range) |
| Softening point | ~150 degC (ASTM D36) |
| Cold flexibility | approx. -5 degC (DIN 52123) |
| Tensile strength | ~750 N/5cm longitudinal, ~550 N/5cm transverse (UEAtc, Torchseal data) |
| Elongation at break | ~40% longitudinal, ~50% transverse (UEAtc, Torchseal data) |
| Roll size | Typically 10 m x 1 m |
| Primer | Fosroc Torchseal Primer at ~0.2-0.8 L/m2 |
| Application method | LPG torch / flame bonding to primed substrate |
| Country of origin | United Kingdom (per supplier listings) |
Industry use cases
High-rise residential & commercial roofing
Waterproofing terrace and roof slabs on Delhi NCR towers, where the membrane is torch-bonded then protected with screed and tiles to survive monsoon ponding and summer heat.
Basements & deep foundations
Tanking of raft slabs and retaining walls in water-table-affected sites; the polyester core resists puncture from backfill and the APP bitumen resists aggressive ground salts.
Car parks & podium decks
Protecting suspended deck and podium slabs above occupied space, with a screed/topping installed over the membrane to take vehicle and foot traffic.
Infrastructure — tunnels & subways
Buried waterproofing to cut-and-cover tunnels, subways and underpasses where a continuous, robust bituminous barrier is needed against hydrostatic pressure.
Bridges & civil works
Deck waterproofing on bridges and approach structures, applied by trained crews and covered with protection and wearing layers per the project method statement.
Frequently asked questions
Is Fosroc Proofex Torchseal 3PV an APP or SBS membrane?
What does the ‘3PV’ in the name mean?
Which primer should be used with Proofex Torchseal 3PV?
Can the membrane be left exposed to sunlight?
What overlaps and testing are required?
How does it compare with liquid waterproofing like Dr. Fixit or a Sika PU coating?
How we position Fosroc Proofex Torchseal 3PV
Within Fosroc’s waterproofing portfolio, Proofex Torchseal 3PV sits in the prefabricated torch-on sheet category, complementing liquid-applied options and pre-applied/self-adhesive systems. It pairs naturally with Fosroc Torchseal Primer and Fosroc protection products, and within the wider range it can be compared with the plain-finish Torchseal 3PI/3P, the heavier 4 mm grades, the mineral-finish 3S/4S/5S sheets, and the SBS-based Proofex SBS where greater low-temperature flexibility is needed. Against competitors, sheet alternatives include Sika’s bituminous membranes, STP (Shalimar) and MBS torch-on membranes, while Dr. Fixit, Sika and STP also offer liquid-applied PU/acrylic and crystalline systems that suit complex detailing. Honest positioning: choose Proofex Torchseal 3PV for large horizontal slabs, basements, podiums and buried structures where a robust, controlled-thickness, puncture-resistant sheet is preferred and trained torch applicators are available; choose a liquid or self-adhesive system where open-flame work is restricted or where intricate penetrations dominate. As an authorised Fosroc distributor for Delhi NCR and pan-India, Space Arc Engineering supplies genuine Proofex Torchseal 3PV with the matching primer and protection system, plus technical guidance, so the specification, materials and method statement stay aligned for a dependable, warranty-friendly result.
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