Nitofoam 45 — Polyurethane Foam Backer Rod for Sealing Expansion Joints in Concrete Structures

FOSROCAuthorised distributor

Fosroc Nitofoam 45

Two-component, HFC-blown rigid closed-cell polyurethane foam, sprayed in situ to give roofs a seamless, lightweight thermal insulation layer ready for a waterproof or fire-rated topcoat.

BrandFosrocCategoryWaterproofingFormA machine-sprayed, two-component rigid closed-cell polyurethane foam (density around 45-50 kg/m3) that builds a…

What is it?

A machine-sprayed, two-component rigid closed-cell polyurethane foam (density around 45-50 kg/m3) that builds a seamless thermal insulation layer directly on the roof deck.

Where is it used?

Exposed RCC roofs, industrial sheds, warehouses, cold-storage envelopes and metal-deck roofs where heat gain and energy cost are a concern.

Why use it?

It cuts roof heat transfer, has no joints or fixings to leak through, bonds to most substrates, and accepts a Fosroc waterproof or fire-rated topcoat to become a complete roof system.

How is it applied?

Applied by trained applicators using metered plural-component spray equipment that mixes Polyol and Isocyanate at the gun; the foam rises and cures in place, built up in passes to the specified thickness.

About Fosroc Nitofoam 45

Nitofoam 45 is Fosroc’s sprayed-in-place roof insulation foam. It arrives as two liquid components, a polyol blend and an isocyanate, that are metered, heated and combined at the spray gun by a specialist applicator. On contact with the roof the mix expands into a rigid, closed-cell polyurethane foam and cures within minutes, leaving a continuous insulating skin that follows every contour of the deck. Because it is HFC-blown and free of CFC and HCFC, it avoids the ozone-depleting blowing agents of older foam systems. The result is a lightweight layer, typically around 45 to 50 kg per cubic metre, that adds very little dead load to the structure while noticeably slowing the flow of heat into the building below.

What sets a sprayed foam apart from board or roll insulation is that there are no boards to cut, no laps to tape and no mechanical fixings to penetrate the deck. The foam bonds directly to concrete, brickwork, timber, particle board and profiled metal sheet, so it works on both new construction and refurbishment. On its own the foam is an insulant, not a finished waterproofing surface, so it is always overcoated. Fosroc pairs it with Brushbond Roofguard, Polyurea FLM or polyurethane coatings to turn the insulated deck into a weatherproof and, where required, fire-rated roof. For Delhi NCR and pan-India projects, Space Arc Engineering supplies the material and arranges trained spray application so specifiers get a system that performs as the data sheet intends.

The technical insight

The insulating power comes from the closed-cell structure. As the two components react, the blowing agent expands the polymer into millions of sealed gas-filled cells. Still gas trapped inside those cells is a far poorer conductor of heat than the solid material around it, which is why a low-density foam blocks heat so effectively for its weight. Because the cells are closed rather than open, the foam does not readily soak up water, and the seamless in-situ rise means there are no board joints or fastener holes acting as thermal bridges or leak paths across the roof. The trade-off is that polyurethane foam degrades under prolonged UV exposure, so the coating on top is not cosmetic; it is what protects the insulation and delivers the actual waterproofing. Treat Nitofoam 45 as the insulating core of a layered roof build-up, never as a standalone finish.

Where it is used

  • Thermal insulation of exposed RCC terrace and flat roofs on commercial and institutional buildings
  • Insulating large-span industrial shed and warehouse roofs to reduce internal heat gain
  • Metal profiled-deck roofs where a seamless, self-adhering insulant is preferred over boards
  • Cold-storage and temperature-controlled facility envelopes
  • Refurbishment of existing roofs where insulation is added without stripping the deck
  • Irregular or curved roof geometries that board insulation cannot easily follow
  • Substrate insulation ahead of a Fosroc Brushbond, polyurethane or polyurea waterproof coat
  • Energy-efficiency upgrades on factories and logistics buildings across India

Key advantages

  • Seamless, jointless coverage with no laps, fixings or fastener penetrations to fail
  • Low weight, roughly 45-50 kg/m3, adds minimal dead load to the roof structure
  • Bonds directly to concrete, brickwork, timber, particle board and sheet metal
  • Closed-cell foam resists water pickup, unlike open-cell or fibrous insulation
  • HFC-blown and free of CFC and HCFC blowing agents
  • Machine spraying gives fast application rates over large roof areas
  • Follows complex and curved geometries that rigid boards cannot
  • Accepts Fosroc waterproof and fire-rated topcoats to form a complete roof system

Limitations & considerations

  • Not a finished waterproofing surface on its own; it must always be overcoated
  • Requires specialist plural-component spray equipment and trained applicators, not a manual or brush-applied product
  • Degrades under prolonged UV exposure if left uncoated, so the topcoat is essential
  • Best sprayed within a controlled ambient window, around 15 to 40 deg C, for correct rise and cure
  • Substrate must be sound, dry and clean; damp or dusty decks compromise adhesion
  • Cured foam is difficult to remove or trim cleanly once it has set on the deck

Selection & best practice

Prepare the deck first: it must be structurally sound, dry, and free of dust, oil and loose material, since adhesion depends entirely on a clean substrate. Spray only within the recommended ambient temperature window (around 15 to 40 deg C) so the foam rises and cures correctly, and avoid application in rain, high wind or on wet decks. Build the foam up in controlled passes to the specified thickness rather than one heavy lift, and check thickness as you go. Overcoat the cured foam promptly with the specified Fosroc system (Brushbond Roofguard, polyurethane or Polyurea FLM) so the insulation is never left exposed to UV. Application should always be carried out by an applicator trained on metered plural-component equipment; Space Arc can arrange both the material and the trained spray crew.

Specifications

Product type Two-component, HFC-blown sprayable rigid closed-cell polyurethane foam
Blowing agent HFC-blown; free from CFC and HCFC
Density Approximately 45-50 kg/m3
Colour Yellow
Components Polyol blend + Isocyanate (ISO), metered and mixed at the spray gun
Application method Machine spray, plural-component metered equipment, in-situ
Substrate adhesion Concrete, brickwork, timber, particle board and sheet metal
Recommended ambient temperature Approximately 15-40 deg C during application
Compatible topcoats Fosroc Brushbond Roofguard, polyurethane and Polyurea FLM coatings

Industry use cases

Industrial and warehousing

Insulating large shed and warehouse roofs to lower internal temperatures and reduce cooling load across big spans.

Commercial buildings

Seamless thermal insulation on exposed RCC terraces before a waterproof Fosroc topcoat, improving comfort on upper floors.

Cold storage and logistics

Continuous closed-cell insulation on temperature-controlled facility envelopes where thermal integrity is critical.

Roof refurbishment

Adding insulation to an existing sound deck without stripping it, then recoating to restore weatherproofing.

Metal-deck roofs

Self-adhering, jointless insulant on profiled sheet roofs where board systems are awkward to fit and seal.

Frequently asked questions

Is Nitofoam 45 a waterproofing product?
No. It is a thermal insulation foam. It resists water pickup because of its closed-cell structure, but it is not a finished waterproof surface and must always be overcoated with a Fosroc waterproofing system such as Brushbond Roofguard or Polyurea FLM.
Can Nitofoam 45 be brush or roller applied?
No. It is a two-component foam that has to be sprayed through metered plural-component equipment that mixes the polyol and isocyanate at the gun. It requires trained applicators and cannot be applied by hand, brush or roller.
What surfaces does it stick to?
It bonds directly to concrete, brickwork, timber, particle board and sheet metal, provided the substrate is sound, dry and clean. This lets it work on both new roofs and refurbishment without mechanical fixings.
Why choose sprayed foam over insulation boards?
Sprayed foam is seamless, with no board joints, laps or fastener penetrations that can become thermal bridges or leak paths. It also follows curved and irregular roof shapes that rigid boards cannot, and it self-adheres to the deck.
Does it need a topcoat?
Yes, always. Uncoated polyurethane foam degrades under UV, so a Fosroc topcoat is essential. The coating protects the foam and provides the actual waterproofing, turning the insulated deck into a complete roof system.
Can Space Arc supply and apply it in Delhi NCR?
Yes. As an authorised Fosroc distributor and applicator, Space Arc Engineering supplies Nitofoam 45 and can arrange trained spray application across Delhi NCR and pan-India, along with the recommended Fosroc topcoat.

How we position Fosroc Nitofoam 45

Nitofoam 45 is the insulating core of a Fosroc roof build-up, not a standalone finish, so it is best specified alongside its topcoats. Pair it with Fosroc Brushbond Roofguard, the fibre-reinforced acrylic elastomeric coating, for a waterproof roof on most commercial and residential decks, or with Fosroc Polyurea FLM where a fast-curing, high-elongation, heavy-duty membrane is needed on car park decks and demanding industrial roofs. Where the requirement is joint sealing rather than area insulation, a movement-joint sealant such as Fosroc Thioflex 600 is the correct product, not a foam. Space Arc also carries roof waterproofing and protective coating systems from other brands in our range, so if a project calls for a different insulation or membrane approach our technical team can advise on the right combination for the deck and budget.

Source Fosroc Nitofoam 45 for your project

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


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