Fosroc Nitoproof 600PF
Single-component, pitch-free liquid polyurethane that cures with atmospheric moisture into a seamless, permanently flexible waterproof membrane for buried and covered concrete structures.
What is it?
A single-component, hydrocarbon-free (pitch-free) liquid-applied polyurethane waterproofing membrane that moisture-cures into a tough, seamless elastomeric barrier on concrete.
Where is it used?
Roofs, podiums, balconies, planters, suspended floors, bathrooms and wet areas, inspection pits, swimming pools, bridge decks, foundations, basements and tunnels – always under a protective screed or render.
Why use it?
Forms a fully bonded, joint-free membrane that bridges cracks up to 2mm, resists aggressive soil and water-borne salts, and chemically cures so it will not re-melt or flow at high ambient temperatures common in India.
How is it applied?
Applied cold by brush, roller or squeegee at a minimum 1.5mm wet film (approx. 2.0 kg/m2), optionally reinforced with fabric, with no special equipment; dense concrete needs no primer.
About Fosroc Nitoproof 600PF
Fosroc Nitoproof 600PF is a liquid-applied, single-component polyurethane waterproofing membrane that belongs to Fosroc’s elastomeric coating family. The “PF” denotes pitch-free (hydrocarbon-free), which distinguishes it from older bitumen- or coal-tar-modified membranes that can leach, stain and re-soften in heat. Supplied as a ready-to-use black liquid, it cures by reaction with atmospheric moisture to form a continuous, seamless, water and vapour-proof film that is fully bonded to the substrate. Because there are no joints, laps or seams, there is no preferential path for water to track laterally – a common failure mode with sheet membranes once a single lap is compromised.
The product is engineered for concrete structures that will be permanently protected from direct sunlight by a screed, render, tiling or backfill. Typical applications across Indian projects include terrace and podium decks, planter boxes, balconies, suspended floor slabs, toilet and bathroom sunken portions, lift pits and inspection chambers, swimming pool shells, bridge decks, raft foundations, retaining walls, basements and tunnels. Its irreversible chemical cure means the cured film will not melt or flow at the elevated rooftop temperatures routinely seen across Delhi NCR and the rest of India, while its low-temperature flexibility (rated to -40 degrees C) keeps it serviceable in cold-store and high-altitude environments.
For specifiers and contractors, the appeal of Nitoproof 600PF is a single-coat, cold-applied system that needs no torching, no special plant and minimal skilled labour. Good-quality dense concrete generally requires no primer; only porous or absorbent substrates need a thinned seal coat of the same product. As an authorised Fosroc distributor and applicator, Space Arc Engineering supplies genuine, batch-traceable material in 25 kg pails together with substrate-preparation guidance, consumption estimating and on-site application support for projects in Delhi NCR and across India.
The technical insight
The performance hinges on a moisture-triggered isocyanate cure: the single-component polyurethane reacts with ambient humidity to build a cross-linked elastomer rather than simply drying. This produces an irreversible chemical bond, so unlike thermoplastic bituminous coatings the cured film cannot re-melt or cold-flow at high rooftop temperatures – a decisive advantage in Indian summers. The cured membrane combines high elongation (500-700% per ASTM D412) with a tensile strength above 1.9 N/mm2, giving it the elasticity to bridge live and shrinkage cracks up to 2mm while still resisting tearing (tear resistance 21 kN/m, ASTM D624). Because cure is humidity-dependent, very dry conditions slow tack-free time and the wet film must not be applied too thick in a single pass, or skinning can trap uncured material beneath. Critically, the membrane is not UV-stable and must be over-laid with a protective screed or render within 14 days; it is a buried/covered-membrane technology, not an exposed roof coating, which is why Fosroc offers UV-resistant aliphatic top coats for exposed details.
Where it is used
- Terrace, podium and balcony decks beneath protective screed or tile bedding
- Planter boxes and landscaped decks (root-resistant, buried application)
- Sunken toilet, bathroom and utility wet-area slabs before backfilling
- Lift pits, inspection pits and inspection chambers
- Swimming pool shells and water-retaining structures
- Bridge decks and approach slabs under wearing course
- Raft foundations, basement rafts and retaining walls (positive and tanking side)
- Tunnel linings and below-grade civil structures in aggressive soils
- Crack and joint pre-treatment / detailing at right-angle fillets and penetrations
Key advantages
- Pitch-free, hydrocarbon-free, non-toxic formulation – no coal-tar leaching, staining or odour
- Single-coat, cold-applied on horizontal and inclined surfaces – no torch, no special equipment
- Seamless and fully bonded – eliminates laps and seams that allow lateral water tracking
- Irreversible chemical cure – film will not melt or flow at high ambient/rooftop temperatures
- High elasticity bridges substrate cracks up to 2mm and recovers from elongation
- Wide service range from -40 degrees C to +70 degrees C suits Indian climate extremes
- Resists aggressive soil conditions, mild acids, alkalis and water-borne salts; does not biodegrade
- Dense, good-quality concrete typically needs no primer, reducing system cost and time
- Can be fabric-reinforced for added robustness at detailing and high-movement zones
Limitations & considerations
- Not UV stable – must be protected by a screed, render or top coat within 14 days of application
- Buried/covered-membrane only; not a finished exposed-roof or trafficable wearing surface on its own
- Moisture-cure means tack-free time and through-cure depend on humidity and temperature
- Single-pass film should not be over-applied; thick coats can skin and trap uncured material
- Flammable (flash point 38 degrees C) – keep away from ignition sources and ventilate well
- Substrate must be clean, sound and dry; porous concrete needs a thinned seal coat first
- Some users are sensitive to resin/isocyanate systems – gloves, eye protection and ventilation required
- Black colour only; not intended as a decorative finish coat
Selection & best practice
Achieve the specified 1.5mm minimum wet film (approximately 2.0 kg/m2) in controlled passes and detail the failure-prone areas first. Ensure the concrete is clean, sound, dry and at least 28 days cured; rake out, fill and pre-treat shrinkage and non-moving cracks with a 1.5mm coat extending 75mm either side, and install a 25 x 25mm fillet at all right-angle junctions, pre-treating angle joints, protrusions and stress points 50-100mm either side and curing overnight before the general coat. Prime only absorbent concrete using 1 part Nitoproof 600PF thinned with 2-4 parts xylene. Reinforce high-movement or critical zones by embedding fabric into a wet 1.5mm coat and over-coating with a further 1.5mm after 24 hours. Allow a minimum 24 hours cure at 25 degrees C, flood-test to 50mm depth for 24 hours where practical, then apply the protective screed or render within 14 days to shield the membrane from UV. Store pails sealed at 5-35 degrees C, invert every other month to prevent settling, and use within the 9-month shelf life.
Specifications
| Product type | Single-component, pitch-free (hydrocarbon-free) liquid polyurethane membrane |
| Cure mechanism | Moisture cure (reaction with atmospheric humidity) |
| Colour | Black |
| Specific gravity | 1.4 |
| Viscosity | 160 poise |
| Solids content | 89% |
| Tack-free time @ 25 degrees C | 3 hours |
| Application temperature range | 5 degrees C to 50 degrees C |
| Service temperature range | -40 degrees C to +70 degrees C |
| Elongation (ASTM D412-90) | 500-700% |
| Tensile strength (ASTM D412-90) | >1.9 N/mm2 |
| Recovery from 350% elongation (ASTM D412-90) | 95% |
| Tensile adhesion (ASTM D4541) | >1.5 MPa |
| Adhesion-in-peel (ASTM C836) | >60 N |
| Tear resistance (ASTM D624-00) | 21 kN/m |
| Initial hardness (ASTM 2240-86) | Shore A 65 |
| Water vapour transmission (2.3mm film) | 0.6 g/m2/hr |
| Water permeability (DIN 1048) | 0 (nil) |
| Crack-bridging | Up to 2mm |
| Minimum wet film thickness | 1.5mm |
| Coverage | Approx. 2.0 kg/m2 at 1.5mm WFT |
| Application method | Brush, roller or squeegee |
| Flash point | 38 degrees C (flammable) |
| Pack size | 25 kg pails |
| Shelf life / storage | 9 months sealed at 5-35 degrees C |
| UV protection | Cover with screed/render within 14 days |
| TDS reference | Nit-600PF/DS/12/19 |
Industry use cases
Residential & Commercial Buildings
Waterproofing terrace and podium decks, sunken bathrooms, balconies and planter boxes beneath screed or tile bedding, where a seamless crack-bridging membrane prevents the lateral seepage typical of failed sheet laps.
Basements & Below-Grade Civil
Tanking of basement rafts, retaining walls and lift pits in aggressive, salt-laden soils, exploiting the membrane’s nil water permeability (DIN 1048) and chemical resistance to water-borne salts and mild acids/alkalis.
Infrastructure & Transportation
Bridge decks, approach slabs and tunnel linings where the membrane sits under a wearing course or protective layer and must tolerate thermal cycling and substrate movement up to 2mm cracks.
Water-Retaining & Recreational
Swimming pool shells, water tanks and reservoirs that require a flexible, fully bonded, non-toxic barrier protected by a finishing screed, render or tiling.
Industrial & Cold Environments
Floor slabs, suspended floors and inspection pits in plants and cold-storage facilities, where the wide -40 to +70 degrees C service range keeps the membrane flexible and intact.
Frequently asked questions
Is Fosroc Nitoproof 600PF an exposed-roof waterproofing coating?
What does the ‘PF’ in Nitoproof 600PF mean?
How much material do I need and what thickness should I apply?
Do I need a primer before applying Nitoproof 600PF?
Can it bridge cracks and accommodate structural movement?
How is Nitoproof 600PF different from cementitious coatings like Fosroc Brushbond?
How we position Fosroc Nitoproof 600PF
Within Fosroc’s waterproofing portfolio, Nitoproof 600PF sits as the buried, single-component PU membrane for covered concrete – complementary to the cementitious Brushbond / Brushbond RFX range used for water tanks and exposed RCC protection, the Proofex pre-applied and self-adhesive sheet systems used for below-grade tanking, and UV-resistant aliphatic top coats such as Nitoproof UVR Top Coat for exposed detailing. It is closely related to Nitoproof 600 Standard, with the PF grade chosen where a strictly pitch-free, non-staining formulation is required. Against the broader Indian market, credible alternatives a specifier may weigh include Sika’s liquid PU membranes (Sikalastic range) and Sikaproof tanking systems, MBS / MYK Schomburg coatings, Dr. Fixit’s PU and polymer-modified waterproofing systems (popular on residential terraces), and STP Limited membranes for below-grade and bridge-deck work. Nitoproof 600PF’s strongest fit is buried, crack-bridging, salt-resistant applications where a seamless cold-applied PU membrane under a protective screed is preferred over sheet or cementitious options. As an authorised Fosroc distributor and applicator, Space Arc Engineering supplies genuine batch-traceable material and matches it to the right companion products and primers for each detail, rather than forcing a single product across the whole structure. Final product selection should always follow the project consultant’s specification and Fosroc’s current technical data sheet.
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