About Fosroc Proofex Metal Strip

Fosroc Proofex Metal Strip is a purpose-made detailing accessory for Fosroc’s TPO (thermoplastic polyolefin) single-ply membrane waterproofing systems. It is not a standalone membrane and not a movement-joint waterstop in the cast-in sense; rather, it solves a specific and recurring site problem: how to terminate a flexible TPO membrane neatly and permanently against a vertical or edge condition.

The product is a composite panel. A 0.6 mm thick TPO film is factory-laminated onto a 0.6 mm thick galvanised steel sheet, giving a nominal total thickness of 1.2 mm. The exposed face is therefore the same TPO chemistry as the field membrane, while the steel core delivers rigidity and a fixable substrate. The underside carries a grey epoxy coating that protects the galvanised steel against corrosion where it sits against concrete or screed. Because the top surface is genuine TPO, the field membrane can be hot-air welded directly to the strip, creating a continuous, homogeneous thermoplastic bond rather than a mechanical lap reliant on adhesives or sealants alone.

In a typical detail, the installer mechanically fastens the metal strip along an upstand, parapet, kerb or around a penetration. The TPO roofing or tanking membrane is then dressed up to the strip and welded onto its TPO face. The result is a crisp, straight termination line that is watertight, mechanically held and resistant to peel-back or wind uplift at the most vulnerable point of any membrane system, the edge. For contractors in India working on podium decks, basement retaining walls, terrace gardens, water tanks and industrial flat roofs, it removes the guesswork from edge detailing and speeds up an otherwise fiddly part of the job.

Space Arc Engineering supplies Proofex Metal Strip as part of complete Fosroc TPO waterproofing packages across Delhi NCR and Pan-India, alongside the membrane, welding consumables and ancillary detailing items, so the system is specified and delivered as a coordinated whole rather than mismatched parts.

The technical insight

The engineering logic of the strip lies in matching chemistries at the bond line. TPO membranes are heat-welded, not glued: when two TPO surfaces are heated to their fusion temperature and pressed together, they coalesce into a single mass with weld strength approaching that of the parent sheet. A bare galvanised flashing cannot achieve this; you would be forced back to adhesives, mastics or mechanical clamping, all of which age, creep and ultimately become the weakest link. By laminating a TPO film onto the steel, Fosroc converts a rigid metal edge into a weldable surface, so the membrane-to-edge joint is as durable as the membrane itself. The galvanised steel core resists bending and provides pull-out resistance for fasteners, which is what holds the membrane down against negative wind pressure at parapets. The grey epoxy coating on the underside is the corrosion safeguard, important in India’s humid coastal and monsoon-exposed environments where an unprotected cut edge of galvanised steel embedded against alkaline concrete would otherwise be prone to attack. The 1.2 mm total build is a deliberate balance: thick enough to stay rigid and hold fixings, thin enough to cut on site with hand shears and to dress around corners.

Where it is used

• Upstand and parapet terminations of TPO membrane on flat and low-slope roofs
• Edge and kerb detailing on podium decks and landscaped terraces
• Terminations around roof penetrations: pipes, vents, ducts, drains and rooflights
• Coping and capping junctions where the membrane must finish against a hard edge
• Basement and retaining-wall membrane terminations at slab and capping levels
• Detailing at gutters, outlets and rainwater drainage transitions
• Vertical terminations on plant rooms, lift overruns and stair cores
• Industrial and warehouse roof edge details requiring a robust, weldable metal trim

Key advantages

• TPO face is hot-air weldable to the field membrane, giving a homogeneous, sealant-free joint
• Galvanised steel core provides rigidity and secure fastener pull-out at vulnerable edges
• Grey epoxy underside coating protects against corrosion in humid and alkaline conditions
• Produces a tidy, straight, professional termination line at upstands and edges
• Speeds up edge detailing compared with site-formed flashings and adhesive laps
• Factory-laminated for consistent quality and reliable weld compatibility
• Cuts cleanly on site with metal shears and dresses around standard corners
• Fully integrated with the Fosroc Proofex TPO membrane system for single-source accountability

Limitations & considerations

• Accessory item only, it is not a standalone waterproofing membrane or a cast-in movement waterstop
• Performance depends on correct hot-air welding to the TPO membrane; requires trained applicators and welding equipment
• Compatible specifically with TPO membrane systems, not a universal flashing for bituminous or PVC membranes
• Requires mechanical fixing to a sound, fixable substrate; not suited to unsupported spans
• The galvanised steel core must not be left with unprotected cut edges in aggressive exposure
• Fosroc product datasheet does not cite a specific IS/ASTM/BS/EN standard for this accessory; specify per the membrane system approval
• Rigid by nature, so tight or complex curved geometries may need preformed accessories instead

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Proofex Metal Strip

Proofex Metal Strip is a detailing accessory, so it should be specified alongside the membrane it serves rather than compared to membranes directly. It is the natural edge-termination partner for Fosroc’s TPO single-ply range such as Proofex OFB and the wider Proofex membrane family, and it sits in the same toolkit as Fosroc waterstops like the Supercast range (for cast-in construction joints) and self-adhesive systems such as Proofex Engage and Proofex 3000 for basement tanking. Where a project standardises on a different membrane chemistry, the equivalent termination accessory from that manufacturer applies: Sika offers metal-faced and laminate termination profiles for its Sarnafil and Sikaplan single-ply systems, and other waterproofing specialists active in India, including STP Limited, MBCC/Master Builders Solutions and Dr. Fixit (Pidilite), supply their own membrane-edge and flashing accessories matched to their systems. The decisive factor is chemistry compatibility at the weld, so the metal strip should always match the membrane being installed. For TPO projects, Proofex Metal Strip is the coordinated, single-source choice, and Space Arc Engineering, as an authorised Fosroc distributor and applicator, supplies it as part of complete, warranty-friendly TPO waterproofing packages across Delhi NCR and Pan-India.

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