Fosroc Cementite — Cement-Based Waterproof Putty Coating for Concrete and Masonry Wet Areas

FOSROCAuthorised distributor

Fosroc Cementite

Ready-mixed cement-based waterproof putty coating for tanks, sumps and wet areas — brushed straight from the container, no site batching required.

BrandFosrocCategoryWaterproofingFormA single-component, factory ready-mixed cement-based waterproof putty coating that dries to a smooth cream finish…

What is it?

A single-component, factory ready-mixed cement-based waterproof putty coating that dries to a smooth cream finish while sealing pores in concrete and masonry.

Where is it used?

Interiors of domestic overhead water tanks, underground sumps, bathroom and basement walls, garden ponds and small dry-season pool repairs.

Why use it?

It fills surface voids and builds a continuous waterproof film in two to three coats, with no on-site mixing and no specialist applicator skills needed.

How is it applied?

Brush, roller or trowel in 2–3 cross-directional coats; recoat after 4–6 hours at 25°C and allow a minimum 7 days of curing before water contact.

About Fosroc Cementite

Cementite is Fosroc’s ready-mixed, cement-based waterproof putty coating — a single-component product that comes off the shelf ready to brush, with none of the powder-and-liquid batching that trips up small waterproofing jobs. Applied in two to three coats over concrete or masonry, its cream putty consistency does two jobs at once: it fills the pores, blowholes and fine voids that let water migrate through a wall, and it builds a continuous cementitious film that keeps stored water in and ground dampness out. Because the chemistry is cement-based, the coating is naturally compatible with the substrates Indian construction actually uses — RCC tank walls, brick masonry sumps and plastered bathroom surfaces.

It has earned its place as the straightforward choice for static, crack-free surfaces: domestic overhead tanks, society sumps, basement walls and pond interiors where movement is negligible and a rigid film performs dependably. Space Arc Engineering supplies genuine Fosroc Cementite across Delhi NCR and Pan-India, backed by practical guidance on coat counts, recoat windows and curing — the details that decide whether a cementitious coating actually holds water.

The technical insight

Cementite works through film formation plus pore blocking. The first coat is drawn into the open capillaries of the substrate, where the cement fraction hydrates and locks mechanically into the surface — which is why the product wants a firm, absorbent base rather than a sealed one. Each subsequent coat, laid perpendicular to the previous pass, closes the pinholes any single brush direction leaves behind and thickens the film into a waterproof barrier. The cured result is a rigid mineral coating, and that rigidity defines its limits: hydrated cement has almost no elastic recovery, so a live crack underneath will telegraph straight through the film. The seven-day cure matters because the coating keeps gaining density as hydration continues — pressurise it with stored water too early and you are testing a soft, still-permeable coat.

Where it is used

  • Internal waterproof coating of domestic overhead water storage tanks in concrete or masonry
  • Waterproof lining of underground sumps and water collection tanks
  • Moisture-resistant wall coating in bathrooms, toilets and wet rooms
  • Interior face of below-ground basement walls for dampness control
  • Concrete interiors of garden ponds and decorative water features
  • Small patch and repair coats in swimming pools during the dry season
  • Pore-filling finish coat over blowhole-marked concrete in water-retaining structures

Key advantages

  • Supplied factory ready-mixed — opens and applies immediately, eliminating site batching errors
  • Cream putty consistency fills pores, blowholes and fine voids as it coats
  • Cement chemistry bonds naturally to concrete, plaster and masonry substrates
  • Applied with an ordinary brush or roller, so regular site painters can handle it
  • Multi-coat build creates a continuous waterproof film suited to water-retaining duty
  • Smooth, uniform cream finish doubles as a presentable final surface
  • Economical and widely stocked for small and mid-sized waterproofing jobs

Limitations & considerations

  • Rigid, low-flexibility film — it will not bridge moving or live cracks and is unsuitable over expansion joints
  • Not a plugging compound: it cannot stop active water leaks, which must be sealed first
  • Needs a full 7 days of curing before the coated surface can hold water
  • Waterproofing depends on completing 2–3 full coats; a single coat is not adequate
  • Coverage drops on porous substrates, so absorbent surfaces consume noticeably more material

Selection & best practice

Begin with a sound, clean substrate: remove laitance, loose plaster, oil and surface contamination, and repair structural cracks or active leaks before any coating starts — Cementite is a finishing waterproofer, not a plugging compound. Stir the container, then brush the first coat firmly into the surface so it penetrates the porosity and establishes the adhesion base. Let each coat firm up before the next — typically 4–6 hours at 25°C, closer to 2–3 hours in Indian summer conditions around 35°C — and lay every following coat perpendicular to the one before, so crossed strokes close residual pinholes. Two to three coats is the standard system, and never fewer than three inside underground sumps. Finally, protect the cure: hold a minimum of seven days before the tank is filled or the surface sees standing water.

Specifications

Product type Ready-mixed cement-based waterproof putty coating
Form Single component, factory ready-mixed
Finish / colour Smooth cream
Application method Brush, roller or trowel
Recommended coats 2–3 (minimum 3 for underground sumps)
Coverage Approx. 1.0–1.5 m² per kg per coat, depending on substrate absorption
Recoat interval 4–6 hours at 25°C; 2–3 hours at around 35°C
Curing before water contact 7 days minimum
Film flexibility Low — for static, crack-free substrates only

Industry use cases

Residential housing

Overhead tank interiors and bathroom walls in individual homes and group housing, where a simple brush-applied system suits small-scale work.

Societies and RWAs

Refurbishment of underground sumps and collection tanks during maintenance shutdowns, using the three-coat sump system.

Commercial facilities

Interior coating of below-ground basement walls to control persistent dampness without major civil intervention.

Landscape and hospitality

Waterproof lining of garden ponds and decorative water features in hotels, farmhouses and institutional campuses.

Maintenance contractors

Dry-season patch and repair coats in swimming pools, where a compatible cementitious finish is needed over concrete.

Frequently asked questions

How many coats do I need for an underground sump?
Apply a minimum of three coats, each laid perpendicular to the previous one after it has firmed up. The first coat fills surface porosity and anchors the system; the cross-directional passes close pinholes and build the waterproof film.
Can Cementite stop an active leak in a tank?
No. It is a rigid finishing coating, not a plugging product. Stop running water first with a rapid-set plugging mortar such as Fosroc Renderoc Plug, then apply Cementite over the repaired, sound surface.
Is it suitable for drinking-water tank interiors?
It is widely used in domestic water tank interiors across India. For drinking-water storage, ask us for the current batch documentation confirming potable-water compliance before you specify it.
Does it need mixing with cement or water on site?
No. Cementite arrives factory ready-mixed as a single component — stir the container and apply directly by brush, roller or trowel. That removes the batching-ratio errors common with site-mixed systems.
Will it bridge cracks in an old tank wall?
No — the cured film has low flexibility and any live crack will reflect through it. Repair cracks first, and where movement or hairline cracking is expected, step up to a flexible coating such as Fosroc Brushbond Flex.
How soon can the tank be filled after coating?
Allow a minimum of seven days of curing at normal ambient temperature before water contact. Filling early loads a film that is still hydrating and can leave it soft and permeable.

How we position Fosroc Cementite

Cementite is the entry point in Fosroc’s water-retaining coatings range: choose it for static, crack-free tanks, sumps and wet areas where simplicity and economy matter most. Where the substrate moves or shows hairline cracking, specify Fosroc Brushbond Flex; for severe leakage-prone structures, the Brushbond RF system offers a heavier-duty cementitious build; and for high-elasticity membrane duty on roofs and podiums, Fosroc Nitoproof 600 is the stronger call. Pair it with Renderoc Plug wherever active leaks must be stopped before coating. Space Arc also stocks comparable cementitious waterproof coatings from Dr. Fixit and Sika — talk to our team if your project specification calls for an alternative brand.

Source Fosroc Cementite for your project

Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.


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