About STP ShaliProtek PU HA

{“name”:”ShaliProtek PU HA”,”slug”:”stp-shaliprotek-pu-ha”,”brand”:”STP”,”realProduct”:”yes”,”officialSource”:”https://stpltd.com/wp-content/upload/TDS/ShaliProtek-PU-HA.pdf”,”category”:”waterproofing”,”metaTitle”:”ShaliProtek PU HA | UV-Stable PU Top Coat | Space Arc”,”metaDescription”:”ShaliProtek PU HA is STP’s water-based elastomeric PU top coat that shields waterproofing membranes from UV and abrasion on Delhi NCR terraces and decks.”,”heroSubtitle”:”STP’s water-borne elastomeric PU top coat that protects your waterproofing membrane from UV, abrasion and monsoon wear, without adding screed load to the roof.”,”glance”:{“whatIsIt”:”A single-component, water-borne, pigmented elastomeric polyurethane top coat engineered as a UV-resistant, high-abrasion protective finish over liquid-applied or preformed waterproofing membranes. It is a protective finish coat, not a standalone waterproofing system.”,”whereUsed”:”Exposed RCC terraces, podium decks, balconies, chajjas, water tank roof surrounds and walkways across Delhi NCR and pan-India projects, wherever a waterproofed roof surface is left open to direct sun, rain and regular foot traffic.”,”whyUse”:”It lets the actual waterproofing membrane underneath do its job protected from UV breakdown and mechanical wear, while avoiding the dead-load penalty of a protective screed, and leaves owners with an easy-to-clean, walkable, seamless finish.”,”howApplied”:”Applied cold by brush, roller or airless spray in one or two coats over a clean, primed, dry substrate (moisture below 5%), with 3-6 hours between coats. Light foot traffic is possible in 18-24 hours; full cure takes 8-10 days.”},”technicalInsight”:”Two numbers in the STP data sheet explain why ShaliProtek PU HA is specified as a topcoat rather than left out of the system: elongation of 500 ± 50% and a documented ‘no cracking’ result under ASTM C 836 crack-bridging. Exposed RCC roofs in the Delhi NCR climate move — day-to-night and seasonal temperature swings open and close hairline cracks in the substrate — and a rigid finish coat would craze and let water track in exactly where it matters least. An elastomeric film that can stretch to five times its length and recover keeps tracking those movements instead of failing at them. The Taber abrasion result (35 mg loss per 1,000 cycles) is the practical reading of the ‘HA’ (High Abrasion) in the name: it is the number that matters when a terrace doubles as a walkway, a service path to a water tank, or an amenity deck, rather than a roof nobody ever walks on. Two things are worth flagging honestly rather than glossing over. First, touch-dry in 30-45 minutes does not mean the coating is finished curing — the isocyanate-based polyurethane network keeps building for 8-10 days, so handover and any secondary works (planters, furniture, tank filling) should be sequenced with that in mind, not just the 18-24 hour foot-traffic window. Second, ‘water-borne’ describes the carrier, not the hazard profile: the TDS is explicit that the product still contains isocyanate and calls for gloves, eye protection and ventilation during application — buyers who assume ‘water-based’ means no PPE needed are working from the wrong assumption.”,”applications”:[“Protective UV topcoat over liquid-applied PU, PMMA or acrylic waterproofing membranes on exposed RCC roofs”,”Finish coat over preformed membranes (TPO/HDPE) that need added UV and wear protection”,”Podium decks and terrace gardens carrying light, regular pedestrian traffic”,”Residential and commercial balconies, sit-outs and chajjas exposed to sun and rain”,”Rooftop water tank surrounds, plant-room walkways and other utility roof areas”,”Refurbishment recoat over an ageing, chalking waterproofing membrane to buy years of extra service life”,”Parapet copings and other horizontal RCC elements left permanently exposed”,”Final wear-and-UV layer on new-build terraces once the primary waterproofing membrane has cured”],”advantages”:[“Removes the need for a protective screed, saving considerable dead load on the roof slab”,”UV-stable, frost-resistant elastomeric finish that resists chalking and colour loss over time”,”High abrasion and wear resistance — Taber Abrader loss of just 35 mg per 1,000 cycles”,”Water-borne formulation is lower-odour and easier for site crews to handle than solvent-based PU coatings”,”Strong measured adhesion to primed concrete and to compatible membranes (2.0 MPa)”,”Straightforward brush, roller or airless-spray application with no specialised plant required”,”High elongation (500%) backed by a documented crack-bridging pass under ASTM C 836″,”Leaves a walkable, easy-to-clean seamless surface suitable for normal foot traffic once cured”],”limitations”:[“Still contains isocyanate despite being water-based, so proper PPE, ventilation and trained handling remain necessary”,”Not freeze/thaw stable in storage — containers must be kept away from frost, direct heat and sunlight”,”Narrow weather window for application — cannot go on below 5°C or when rain, dew or frost is expected within 48 hours”,”It is a topcoat, not a waterproofing membrane in its own right, and must be paired with a compatible base system”,”Full cure takes 8-10 days, so a terrace should not be treated as completely serviced the moment foot traffic resumes at 18-24 hours”,”Real-world coverage typically runs higher than the 0.4-0.7 kg/m² per coat quoted, since that figure assumes a smooth surface under optimum conditions”],”bestPractice”:”Let new concrete cure a full 28 days and grind away laitance, old coatings, dust, oils and any loose material before coating; substrate moisture should read under 5% and be within 10-40°C. Stir the material at a slow ~400 rpm with a mixing paddle and let it stand briefly so entrapped air can escape — do not over-thin beyond a minor addition of purified water. Apply in one or two coats to a 200-micron DFT target, leaving 3-6 hours between coats, and check the 48-hour weather forecast before starting since rain, dew or frost during cure will compromise the film. On membrane-to-topcoat compatibility and coat count, it’s worth having a Space Arc applicator confirm the system match before ordering, since consumption and coat build vary with the specific base membrane and substrate porosity.”,”specs”:[{“property”:”Chemistry / Type”,”value”:”Single-component, water-borne, pigmented elastomeric polyurethane top coat”},{“property”:”Form / Colour”,”value”:”White liquid; other RAL shades available on request”},{“property”:”Density”,”value”:”1.33 ± 0.03 g/cc”},{“property”:”Total Solid Content”,”value”:”62 ± 2% by weight (ASTM D 2369)”},{“property”:”Tensile Strength”,”value”:”2.0 ± 0.2 MPa (ASTM D 412)”},{“property”:”Elongation at Break”,”value”:”500 ± 50% (ASTM D 412)”},{“property”:”Coverage”,”value”:”0.4-0.7 kg/m² per coat at 200 micron DFT (smooth surface, optimum conditions)”},{“property”:”Water Absorption”,”value”:”< 2% (IS 13826 Part 3)”},{“property”:”Pack Size”,”value”:”20 kg container”}],”useCases”:[{“sector”:”Residential retrofit, Delhi NCR”,”detail”:”Recoating an ageing, chalked liquid-PU terrace membrane ahead of monsoon to restore UV protection and abrasion resistance without redoing the base waterproofing.”},{“sector”:”Commercial podium deck, Gurugram”,”detail”:”Protective topcoat over a liquid PU membrane beneath a landscaped podium, chosen specifically because it avoids the extra screed load a paver-protection build-up would add.”},{“sector”:”Institutional rooftop, water-tank surrounds”,”detail”:”Finish coat on the walkway around an overhead tank, providing an abrasion-resistant, easy-to-clean surface for routine maintenance access.”},{“sector”:”New-build residential terrace”,”detail”:”Applied as the final UV and wear layer over a freshly cured liquid PU waterproofing system on flat-owner terraces before handover.”},{“sector”:”Refurbishment / AMC work”,”detail”:”Used by facility teams as a lower-cost way to extend a membrane’s working life by several years instead of committing to a full membrane replacement.”}],”faq”:[{“q”:”Is ShaliProtek PU HA a waterproofing membrane on its own?”,”a”:”No. It is a protective top coat, not a standalone waterproofing system — it needs to be applied over a compatible waterproofing membrane (liquid-applied PU/PMMA/acrylic or preformed) rather than directly on bare structural concrete as the sole waterproofing layer.”},{“q”:”Can we walk on the terrace after it’s coated?”,”a”:”Yes, it’s designed for normal pedestrian traffic. The data sheet lists light foot-traffic readiness at 18-24 hours, but full cure takes 8-10 days, so heavier use or furniture placement is best held off until then.”},{“q”:”Is it safe to apply given it’s water-based?”,”a”:”It’s lower-odour and easier to handle on site than a solvent-borne PU, but it still contains isocyanate, so gloves, eye protection and good ventilation are required during application regardless of the water-based carrier.”},{“q”:”What’s the shelf life and how should it be stored?”,”a”:”12 months in unopened, sealed containers, kept in a shaded area away from heat, sunlight and frost — it is not freeze/thaw stable, so containers must not be allowed to freeze.”},{“q”:”Does the surface need a primer before coating?”,”a”:”For direct application over cured, primed concrete it needs a compatible primer; when it’s being used as a topcoat over an existing waterproofing membrane, it goes onto the clean, prepared membrane surface itself — a Space Arc applicator can confirm the right system build for your substrate.”},{“q”:”Can it be applied just before or during the monsoon?”,”a”:”Not if rain, dew or frost is expected within 48 hours of application, and never below 5°C — high humidity and moisture during cure will affect film formation, so timing the application window matters as much as the product choice.”}],”positioning”:”ShaliProtek PU HA sits at the finishing end of STP’s own polyurethane waterproofing family — it’s the topcoat commonly paired with STP’s ShaliProtek PuR-series liquid PU membranes (PuR 100, PuR H, PuR L, PuR 40) and the ShaliUrethane LHM range, so projects already running an STP PU system can stay single-brand end to end. For specifiers comparing suppliers, Fosroc is the natural reference point in the PU waterproofing space with its Nitoproof PU range (e.g., Nitoproof 650PU), though Fosroc typically bundles UV-protective topcoating as part of that system rather than selling a directly equivalent named product — so a like-for-like swap isn’t exact, and the choice usually comes down to which base membrane system is already specified on the job rather than the topcoat alone.”}

The technical insight

Two numbers in the STP data sheet explain why ShaliProtek PU HA is specified as a topcoat rather than left out of the system: elongation of 500 ± 50% and a documented ‘no cracking’ result under ASTM C 836 crack-bridging. Exposed RCC roofs in the Delhi NCR climate move — day-to-night and seasonal temperature swings open and close hairline cracks in the substrate — and a rigid finish coat would craze and let water track in exactly where it matters least. An elastomeric film that can stretch to five times its length and recover keeps tracking those movements instead of failing at them. The Taber abrasion result (35 mg loss per 1,000 cycles) is the practical reading of the ‘HA’ (High Abrasion) in the name: it is the number that matters when a terrace doubles as a walkway, a service path to a water tank, or an amenity deck, rather than a roof nobody ever walks on. Two things are worth flagging honestly rather than glossing over. First, touch-dry in 30-45 minutes does not mean the coating is finished curing — the isocyanate-based polyurethane network keeps building for 8-10 days, so handover and any secondary works (planters, furniture, tank filling) should be sequenced with that in mind, not just the 18-24 hour foot-traffic window. Second, ‘water-borne’ describes the carrier, not the hazard profile: the TDS is explicit that the product still contains isocyanate and calls for gloves, eye protection and ventilation during application — buyers who assume ‘water-based’ means no PPE needed are working from the wrong assumption.

Where it is used

• Protective UV topcoat over liquid-applied PU, PMMA or acrylic waterproofing membranes on exposed RCC roofs
• Finish coat over preformed membranes (TPO/HDPE) that need added UV and wear protection
• Podium decks and terrace gardens carrying light, regular pedestrian traffic
• Residential and commercial balconies, sit-outs and chajjas exposed to sun and rain
• Rooftop water tank surrounds, plant-room walkways and other utility roof areas
• Refurbishment recoat over an ageing, chalking waterproofing membrane to buy years of extra service life
• Parapet copings and other horizontal RCC elements left permanently exposed
• Final wear-and-UV layer on new-build terraces once the primary waterproofing membrane has cured

Key advantages

• Removes the need for a protective screed, saving considerable dead load on the roof slab
• UV-stable, frost-resistant elastomeric finish that resists chalking and colour loss over time
• High abrasion and wear resistance — Taber Abrader loss of just 35 mg per 1,000 cycles
• Water-borne formulation is lower-odour and easier for site crews to handle than solvent-based PU coatings
• Strong measured adhesion to primed concrete and to compatible membranes (2.0 MPa)
• Straightforward brush, roller or airless-spray application with no specialised plant required
• High elongation (500%) backed by a documented crack-bridging pass under ASTM C 836
• Leaves a walkable, easy-to-clean seamless surface suitable for normal foot traffic once cured

Limitations & considerations

• Still contains isocyanate despite being water-based, so proper PPE, ventilation and trained handling remain necessary
• Not freeze/thaw stable in storage — containers must be kept away from frost, direct heat and sunlight
• Narrow weather window for application — cannot go on below 5°C or when rain, dew or frost is expected within 48 hours
• It is a topcoat, not a waterproofing membrane in its own right, and must be paired with a compatible base system
• Full cure takes 8-10 days, so a terrace should not be treated as completely serviced the moment foot traffic resumes at 18-24 hours
• Real-world coverage typically runs higher than the 0.4-0.7 kg/m² per coat quoted, since that figure assumes a smooth surface under optimum conditions

Selection & best practice

Specifications

Industry use cases

How we position STP ShaliProtek PU HA

ShaliProtek PU HA sits at the finishing end of STP’s own polyurethane waterproofing family — it’s the topcoat commonly paired with STP’s ShaliProtek PuR-series liquid PU membranes (PuR 100, PuR H, PuR L, PuR 40) and the ShaliUrethane LHM range, so projects already running an STP PU system can stay single-brand end to end. For specifiers comparing suppliers, Fosroc is the natural reference point in the PU waterproofing space with its Nitoproof PU range (e.g., Nitoproof 650PU), though Fosroc typically bundles UV-protective topcoating as part of that system rather than selling a directly equivalent named product — so a like-for-like swap isn’t exact, and the choice usually comes down to which base membrane system is already specified on the job rather than the topcoat alone.

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