Fosroc Nitoproof 725
A one-component, water-based modified-polyurethane-hybrid liquid membrane engineered for exposed, UV-bombarded Indian rooftops — seamless, cool-roof reflective and fire-rated.
What is it?
A single-component, cold-applied, water-based modified polyurethane (PU) hybrid elastomeric liquid-applied waterproofing membrane from Fosroc, designed specifically for exposed roof decks.
Where is it used?
Exposed RCC roof slabs, flat and sloping roofs, serviced and walk-on (non-permanent traffic) roofs, cool-roof retrofits and waterproofing refurbishment across residential, commercial and institutional buildings.
Why use it?
It cures to a seamless, UV-stable, colour-stable membrane with SRI 106 (white) for heat-island reduction, ASTM E108 Class A fire rating, >350% elongation and 2 mm crack-bridging — ideal for the harsh sun and thermal cycling of Indian terraces.
How is it applied?
Brush, roller, squeegee or airless spray over a primed substrate in one coat at 1.3-1.4 mm WFT, or two cross-applied coats at 0.65-0.7 mm WFT each, achieving 0.8-0.9 mm total DFT.
About Fosroc Nitoproof 725
Fosroc Nitoproof 725 is a liquid-applied waterproofing membrane built around Fosroc’s FEWS (Fire, Environment, Waterproofing, Solar) technology, which fuses synthetic polymer and polyurethane resin chemistries into a single water-based modified-PU-hybrid system. Unlike conventional torch-applied APP/SBS bituminous membranes or solvent-based PU coatings, Nitoproof 725 is supplied ready-to-use as a one-component product and is applied cold — there is no flame, no hot bitumen and no two-part mixing on site. The cured film is a tough, flexible elastomer that bonds directly to the deck and forms a fully seamless monolithic skin with no laps, joints or weak seams. It is purpose-built for exposed roof situations where the membrane will face direct sun, where UV degradation and colour fade are concerns, and where the project demands a fire-rated, cool-roof, low-VOC solution. For Indian developers, consultants and applicators, this positions Nitoproof 725 as a premium exposed-roof waterproofing-plus-cool-roof coating in a single product, rather than a buried or screed-protected membrane.
The technical insight
The defining feature of Nitoproof 725 is that it delivers four distinct performance functions from one water-based coat. As a waterproofer it resists 10 m water-head pressure and bridges static and dynamic cracks up to 2 mm (ASTM C836). As a fire barrier it is rated ASTM E108 Class A for roof coverings — a genuine differentiator versus most bituminous and many PU membranes. As a cool roof it achieves a Solar Reflectance Index of 106 in white (ASTM E1980), reflecting solar load and qualifying for LEED v4.1 heat-island-reduction credit. And as an exposed coating it passes 2,000 hours QUV-A weathering (ASTM D4587) for UV and colour stability. The mechanical envelope is genuinely elastomeric: 1.75 MPa tensile strength with greater than 350% elongation at break (ASTM D412), 75 Shore A hardness, and strong adhesion of 1.9 MPa to concrete and 1.5 MPa to steel/aluminium (ASTM D4541/D7234). At 62% solids by volume it is water-vapour permeable (3.1 g/m²/day, ASTM E96), so the deck can breathe rather than trap interstitial moisture, and it carries a wide -10 deg C to +90 deg C service range plus root resistance (CEN/TS 14416) and mould resistance (ASTM D3273, rating 10). Critically, it is single-component water-based chemistry, so the on-site failure modes of incorrect two-pack ratios and solvent flash-off are eliminated — the trade-off is sensitivity to ambient conditions during cure.
Where it is used
- Waterproofing of exposed RCC flat and sloping roof slabs in new construction
- Cool-roof coating to cut rooftop heat gain and reduce air-conditioning load on terraces and top floors
- Waterproofing refurbishment and re-roofing over sound existing roof substrates
- Serviced roofs and plant-deck areas with intermittent (non-permanent) foot traffic
- Detailing of upstands, parapets, drains, gutters, coving and penetrations using Nitoproof Scrim reinforcement
- Ballasted (gravel-protected) roofs where the membrane is covered with a non-woven geotextile
- Treatment of shrinkage and non-moving structural cracks as a localised pre-treatment coat
- LEED-targeted projects requiring heat-island reduction and low-VOC roofing materials
Key advantages
- One-component and ready to use — no mixing ratios to get wrong, faster mobilisation on site
- Cold-applied and water-based — no torch, no hot works, low VOC and low odour, safer on occupied buildings
- Seamless monolithic membrane with no laps or seams to fail, conforming to complex roof geometry
- UV-resistant and colour-stable for permanent exposed-roof service (passes 2,000 hr QUV-A)
- High solar reflectance (SRI 106, white) for cool-roof and LEED heat-island-reduction benefit
- ASTM E108 Class A fire rating — a strong specification advantage over bituminous systems
- Excellent flexibility: >350% elongation and 2 mm crack-bridging accommodate thermal and structural movement
- Water-vapour permeable, so the roof slab is not moisture-trapped under the film
- Root- and mould-resistant, suitable for green/ballasted roof build-ups with geotextile
- Strong adhesion to concrete (1.9 MPa) and metal (1.5 MPa) for a fully bonded membrane
Limitations & considerations
- Not suitable for permanent pedestrian traffic — needs tiling/screed protection for walk-on decks
- Must not be permanently immersed or subjected to permanent ponding/standing water
- Application is weather-sensitive: do not apply below 5 deg C ambient/substrate, above 85% RH, or when rain is expected within the walkable time (up to 24 hr)
- Substrate moisture must be <6% with no rising/negative-pressure moisture, confirmed by polyethylene-sheet test
- Substrate temperature must be at least 3 deg C above dew point at the time of application
- Priming is mandatory on porous/absorbent substrates such as concrete (1:1 Nitoproof 725 : water)
- Not resistant to chemical or oil spillage — any contamination must be removed immediately
- Cannot take permanent static point loading without a protection layer in place
- Being water-based it must be protected from freezing in storage and before cure
Selection & best practice
Specify Nitoproof 725 to a minimum 0.8 mm DFT and verify it on site. Prepare the deck thoroughly — surfaces must be clean, sound and free of laitance, oil, curing compound and organic growth; abrasive blasting is the preferred preparation to provide a key. Make good surface irregularities with a Fosroc Nitomortar FC/FCB or Renderoc product before coating. Always prime porous concrete with a 1:1 Nitoproof 725-to-clean-water mix and let it soak in and dry to a tacky state. Detail all the weak points first: pre-treat cracks with a 1.3 mm wet coat 75 mm either side, install cant strips/coving at all angles, and reinforce movement joints, coving and stress points with Nitoproof Scrim sandwiched between two 0.65-0.7 mm wet coats, sealing movement joints with Nitoseal MS600 over debonding tape. For the main field, prefer the two-coat method applying the second coat at 90 deg to the first for an even, pinhole-free film totalling 1.3-1.4 mm WFT / 0.8-0.9 mm DFT. Stir for 1-2 minutes on slow speed without entraining air. Cure the membrane at least 48 hours before a 24-hour flood test to 50 mm depth, and protect it with a screed or boards (over a separation sheet) wherever backfilling, traffic or ballast will follow.
Specifications
| Chemical type | One-component, water-based, cold-applied modified polyurethane (PU) hybrid elastomeric membrane |
| Solids by volume | 62% |
| Density | 1.3 g/ml |
| Tensile strength (ASTM D412) | 1.75 MPa |
| Elongation at break (ASTM D412) | >350% |
| Hardness | 75 Shore A (ASTM D2240) |
| Adhesion to substrate (ASTM D4541/D7234) | 1.9 MPa to concrete; 1.5 MPa to steel/aluminium |
| Crack-bridging, static/dynamic (ASTM C836) | 2 mm |
| Resistance to water pressure | 10 m head |
| Water-vapour transmission (ASTM E96) | 3.1 g/m²/day (47.8 gr/m²/day) |
| Solar Reflectance Index (ASTM E1980, white) | 106 |
| Fire rating (ASTM E108) | Class A (roof waterproofing) |
| UV / colour stability | Pass, 2,000 hrs QUV-A (ASTM D4587) |
| Root resistance | Pass (CEN/TS 14416) |
| Mould-growth resistance (ASTM D3273) | Pass, rating 10 |
| Service temperature | -10 deg C to +90 deg C |
| Surface touch-dry time | ~1 hr at 50 deg C/<20% RH; ~2.5 hr at 25 deg C/55% RH; ~5 hr at 5 deg C/70% RH |
| Walkable time | <24 hrs |
| Recommended DFT | 0.8-0.9 mm (minimum 0.8 mm dft) |
| Wet film thickness | 1.3-1.4 mm total (1 coat) or 0.65-0.7 mm per coat (2 coats) |
| Coverage | 15 m² per 20 litre pail at 1.3 mm WFT (0.8 mm DFT); primer ~7 m²/litre |
| Pack size | 20 litre pail |
| Colour | White (high SRI); other colours available — confirm with Fosroc |
| Shelf life / storage | 12 months, +5 deg C to +30 deg C, dry, original sealed pails, protect from freezing |
Industry use cases
Commercial & IT parks
Cool-roof waterproofing of large exposed RCC roof decks to reduce solar heat gain and HVAC load while meeting LEED heat-island-reduction and low-VOC credits.
Residential high-rise & housing
Seamless exposed-terrace waterproofing on apartment rooftops where torch-on hot works are restricted and a UV-stable, walkable (intermittent) finish is needed.
Institutional & healthcare
Fire-rated (ASTM E108 Class A) roof waterproofing for hospitals, schools and public buildings where roof-covering fire performance is specified.
Industrial & warehousing
Refurbishment re-coating of large ageing roofs and plant decks, with geotextile-protected ballasted build-ups over the membrane.
Hospitality & green roofs
Root-resistant base waterproofing under landscaped/ballasted roof gardens on hotels and clubhouses, protected by non-woven geotextile.
Frequently asked questions
Is Fosroc Nitoproof 725 a real product, and what exactly is it?
How much Nitoproof 725 do I need per square metre?
Does it need a primer and how many coats?
Can people walk on a Nitoproof 725 roof?
Is it suitable for hot Indian rooftops and the monsoon?
How is it different from a torch-applied bituminous membrane?
How we position Fosroc Nitoproof 725
Within the Fosroc range, Nitoproof 725 is the premium exposed-roof, cool-roof-rated tier of the Nitoproof liquid-membrane family — sitting above general-purpose options such as Nitoproof PUW/600 and the budget Nitoproof Dampproof/Damp Protect lines, and complemented on site by Nitoproof Scrim reinforcement, Nitoseal MS600 joint sealant with Nitoseal Debonding Tape, and the Nitomortar/Renderoc repair mortars used to make good the substrate. Its real differentiator is the combination of fire rating, high SRI and single-component water-based handling in one product, which not every competing membrane matches. Honestly assessed, credible alternatives an Indian consultant would weigh include Sika’s liquid-applied PU roof systems such as Sikalastic-560 and the SikaRoof MTC range, the cementitious and PU-hybrid roof coatings from Dr. Fixit (Pidilite) like Newcoat/Roofseal, MBS/MYK Laticrete elastomeric and crystalline waterproofing options, and STP Limited’s liquid and bituminous roofing membranes. For deep buried-deck, podium or wet-area tanking, a high-elongation PU like Nitoproof PUW or a cementitious crystalline system is usually a better fit than 725; choose Nitoproof 725 specifically when the roof is exposed and the project values UV/colour stability, cool-roof SRI and a Class A fire rating. As an authorised Fosroc distributor and applicator, Space Arc Engineering can supply Nitoproof 725 with the correct primers, scrim and ancillaries and advise on system selection across Delhi NCR and Pan-India.
Related Waterproofing products
Source Fosroc Nitoproof 725 for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.