Fosroc Dekguard PU
Two-component polyurethane protective topcoat that shields concrete and steel against aggressive chemicals, chlorides and long-term UV exposure.
What is it?
A high-quality, two-pack (base plus hardener) polyurethane protective coating that cures to a tough, glossy or matt film with excellent chemical, chloride and UV resistance. It is a topcoat system, not a thick waterproofing membrane.
Where is it used?
Sewage and effluent works, chemical processing plants, marine structures such as jetties, piers, seawater intakes and channels, and any concrete or steel surface facing an aggressive atmosphere or submerged service.
Why use it?
It resists chalking, yellowing and a wide range of acids, alkalis and solvents while staying colour-stable under sunlight, so protected assets stay serviceable and easy to clean over a long life.
How is it applied?
Priced surfaces are primed with Dekguard EP302 epoxy, then Dekguard PU is roller, brush or airless-spray applied in one or two coats at 95 to 145 microns wet film, curing to 50 to 75 microns dry per coat.
About Fosroc Dekguard PU
Fosroc Dekguard PU sits at the protective end of the Dekguard family. Where the anti-carbonation coatings in that range are built mainly to keep carbon dioxide and rain out of atmospherically exposed concrete, Dekguard PU is engineered for the harder environments an Indian project throws up: the inside of an effluent tank, the deck of a jetty, a channel carrying chemically loaded water, or steelwork standing in coastal air. It is supplied as a two-pack, solvent-based polyurethane in pre-weighed base and hardener tins, so the crew simply combines full packs on site and applies without any guesswork on ratios. The cured film is genuinely tough, hard to mark or disfigure, and stands up to repeated cleaning with strong solvent-based detergents.
For engineers and consultants specifying corrosion protection, the appeal is the combination the single-pack alternatives struggle to deliver at once. Dekguard PU keeps its colour and gloss, shrugs off chalking and yellowing, blocks chloride ingress, and holds a low carbon dioxide diffusion figure of 1.0 x 10 to the power minus 7 cm squared per second, all while carrying real chemical resistance across acids, alkalis, solvents and aqueous media. It bonds to concrete, steel and fully cured epoxy alike, which lets a specifier colour-match dissimilar elements of a structure under one finish. As an authorised Fosroc distributor and applicator, Space Arc supplies the full Dekguard PU and EP302 system across Delhi NCR and Pan-India, with application guidance for the substrate in front of you.
The technical insight
The performance comes from the isocyanate-cured polyurethane backbone. Once the hardener is mixed into the resin base, the two components crosslink into a dense, chemically stable film at 52 percent solids by volume, and that crosslinked network is what resists solvent attack and repeated detergent cleaning without softening. The polyurethane chemistry is inherently colour and gloss stable under ultraviolet light, so unlike aromatic or single-part systems it does not chalk or yellow when left exposed on a jetty or an external tank. The tight film also holds a very low carbon dioxide diffusion coefficient, meaning it slows the carbonation front that would otherwise reach the reinforcement, while its impermeability keeps chloride ions and waterborne contaminants off the substrate. Because adhesion, not just barrier action, decides service life, the system is designed to run over a Dekguard EP302 epoxy primer on concrete and steel, giving the topcoat a properly keyed, high-build base to bond into.
Where it is used
- Internal linings and external faces of sewage works, effluent plants and wastewater channels
- Chemical processing and industrial plant where surfaces meet acids, alkalis and solvents
- Marine structures including jetties, piers, harbours, seawater intakes and channels
- Submerged or intermittently submerged concrete and steel in aggressive water
- Steel plant, tanks and structural steelwork needing colour-stable corrosion protection
- Atmospherically exposed reinforced concrete requiring anti-carbonation and chloride resistance
- Recoating and colour-matching of dissimilar concrete and steel elements under one finish
- Over-coating of fully cured epoxy or polyurethane systems that are soundly adhered
Key advantages
- Excellent resistance to a wide band of acids, alkalis, solvents and aqueous chemicals
- Outstanding UV, chalking and yellowing resistance keeps colour and gloss on exposed work
- Blocks chloride ingress and holds a low carbon dioxide diffusion of 1.0 x 10^-7 cm2/s
- Bonds to concrete, steel and fully cured epoxy, allowing one finish across mixed elements
- Two-pack chemistry avoids the curing problems of single-part polyurethane alternatives
- Tough, easily cleaned surface tolerates powerful solvent-based detergents
- Available in gloss or matt and in White, Off-white, Grey and Clear, with custom colours to order
- Marine grade version available where a biocidal, micro-biostatic effect is needed
Limitations & considerations
- Solvent-based and isocyanate-containing, so it needs good ventilation and air-fed respirators in confined spaces
- Flammable, with a flash point of 23 degrees C, and must be kept away from naked flame
- Requires a Dekguard EP302 epoxy primer on concrete and steel; it is not a direct-to-metal one-coat system
- It is a thin-film protective topcoat, not a thick crack-bridging waterproofing membrane
- Minimum application temperature is 5 degrees C and the substrate must be clean, dry and properly prepared
- Full chemical and mechanical cure takes 7 days at 20 degrees C before aggressive service
Selection & best practice
Get the substrate right before anything else. On concrete, remove all laitance by grit blasting or water jetting to ACI 503R-89 and fill surface irregularities with the appropriate Nitomortar product; on steel, blast to a bright SA 2 and a half finish. Prime concrete and steel with Dekguard EP302 and let it dry completely, typically 4 hours at 20 degrees C, before the topcoat goes on. Mix full packs only, combining the entire hardener tin into the base with a slow-speed mechanical paddle for 3 to 5 minutes; if the mix aerates, let it stand 10 to 15 minutes. Apply Dekguard PU by brush, roller or airless spray as a continuous film at 95 to 145 microns wet per coat, and where two coats are used pick a contrasting colour for the second so unbroken coverage is easy to confirm. Respect the recoat window, keep the work well ventilated, use air-fed respirators in confined areas, and clean tools with the appropriate Fosroc solvent immediately after use.
Specifications
| Product type | Two-pack solvent-based polyurethane protective topcoat |
| Solids by volume (mixed) | 52% at 25 degrees C |
| Specific gravity (mixed) | 1.3 |
| Film thickness per coat | 95-145 microns wet, curing to 50-75 microns dry |
| Coverage (theoretical) | 6-10 m2 per litre, substrate and wastage dependent |
| Carbon dioxide diffusion | 1.0 x 10^-7 cm2/s |
| Pot life / full cure | 2 hrs at 20 degrees C; full cure 7 days at 20 degrees C |
| Primer / pack size | Dekguard EP302 epoxy primer; supplied in 20 litre packs |
| Colours and finish | White, Off-white, Grey, Clear; gloss or matt |
Industry use cases
Water and Wastewater
Coating internal and external concrete and steel in sewage works, effluent plants and channels where surfaces face constant chemical and biological attack.
Marine and Coastal
Protecting jetties, piers, harbour structures and seawater intakes against chlorides, submersion and coastal UV, with a marine grade option for biocidal effect.
Chemical and Process Plant
Lining and finishing plant surfaces exposed to acids, alkalis and solvents, where a hard, cleanable, chemically resistant film reduces maintenance cost.
Industrial Steel and Structures
Giving structural steelwork and tanks a colour-stable, chalk-free protective finish that can be matched across adjacent concrete elements.
Reinforced Concrete Durability
Applying anti-carbonation and chloride-barrier protection to atmospherically exposed RCC to slow the carbonation front reaching the reinforcement.
Frequently asked questions
Is Dekguard PU a waterproofing membrane?
Do I need a primer, and which one?
What coverage and pack size should I plan for?
Which colours and finishes are available?
What are the health and safety points for application?
How is it different from Dekguard S?
How we position Fosroc Dekguard PU
Dekguard PU is the heavy-duty, chemical and immersion grade member of the Fosroc Dekguard protective-coating family, always paired with its Dekguard EP302 epoxy primer. Where a project needs anti-carbonation and weather protection on atmospherically exposed concrete rather than chemical or submerged resistance, the sister products Dekguard S (aliphatic acrylic, decorative) and the elastomeric, crack-accommodating Dekguard E2000 are usually the better and more economical fit. For surface repair and reprofiling ahead of coating, the Fosroc Nitomortar and Renderoc mortars complete the system. Space Arc also stocks equivalent protective and anti-carbonation coatings from Sika and MC-Bauchemie where a project specification or approved-vendor list calls for a different brand.
Related Protective Coatings products
Source Fosroc Dekguard PU for your project
Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.