Sika Sikafloor-359 N
Two-component, tough-elastic polyurethane seal coat that locks broadcast aggregate, bridges fine cracks and gives decks and warehouse floors a hard-wearing, non-yellowing matt finish.
What is it?
A 2-part, tough-elastic polyurethane seal coat that binds the broadcast quartz layer of a resin floor and forms the tough, watertight wearing surface on top.
Where is it used?
Car park decks and ramps, warehouse and loading-dock floors, and other medium-to-heavy-traffic industrial areas where a broadcast, crack-bridging system is specified.
Why use it?
It ties down the aggregate for slip resistance, bridges fine shrinkage cracks, resists abrasion and stays non-yellowing under a matt finish, so the deck looks and performs well for years.
How is it applied?
Mix Part A and Part B (78:22 by weight) for about two minutes, then squeegee or roller-apply over the primed and broadcast substrate at roughly 0.7-0.9 kg/m per layer.
About Sika Sikafloor-359 N
Sikafloor-359 N is the seal coat that finishes off a Sika broadcast flooring system. In a typical build-up you prime the concrete, lay a body coat, blind it with dry quartz sand, and then seal the whole thing with a tough-elastic polyurethane that locks the aggregate in place and takes the traffic. That top layer is exactly what Sikafloor-359 N is engineered to be. It is a two-component product: a pigmented Part A resin and a Part B hardener that cure together into a coloured, watertight film with a low-sheen matt look. Because it is polyurethane rather than a rigid epoxy, it keeps a degree of elasticity after curing, which is what lets it ride over the small movements and hairline cracks that concrete decks inevitably develop.
For Indian projects this combination of properties is genuinely useful. Multi-level car parks, ramps and warehouse floors see point loads, tyre scrubbing, oil and water, and daily temperature swings, and a brittle coating simply chips and delaminates. Sikafloor-359 N was formulated for that duty: abrasion-resistant, crack-bridging, watertight and non-yellowing, so a light grey or buff deck does not go patchy or amber under UV and headlights. Space Arc supplies it as part of complete deck and industrial-floor specifications across Delhi NCR and pan-India, and our applicators install it to the same build-up the manufacturer intends, rather than as a standalone paint.
The technical insight
The performance comes down to the polyurethane chemistry and the way the seal coat interacts with the broadcast layer beneath it. When Part A and Part B react, they build long, cross-linked polyurethane chains that stay tough-elastic rather than glass-hard. That elasticity is the mechanism behind the crack-bridging claim: as a fine shrinkage crack opens in the concrete, the film stretches across it instead of tearing, keeping the surface watertight and protecting the reinforcement below from chloride and water ingress. At the same time the coat penetrates into and encapsulates the dry quartz sand that was broadcast into the body coat, gluing every grain down so the finished floor is slip-resistant but does not shed aggregate under traffic. The relatively high solids content (around 85%) means most of what you apply stays on the floor as cured film, giving a dense, abrasion-tough layer, reflected in a Taber abrasion loss of about 160 mg and a Shore D hardness near 52 after seven days. Non-yellowing pigmentation and a stable aliphatic-type PU backbone keep the colour and matt finish consistent even where sunlight or vehicle lighting hits the deck.
Where it is used
- Wearing and seal coat for broadcast (sand-blinded) resin flooring systems
- Intermediate and top decks of multi-storey and basement car parks
- Vehicle ramps and turning areas needing slip resistance
- Warehouse, distribution-centre and factory floors under forklift and pallet traffic
- Loading docks and goods-handling areas exposed to oils and water
- Crack-bridging protective coating over sound concrete decks
- Areas where a coloured, non-yellowing matt finish is specified for aesthetics
- Watertight surfacing over occupied spaces where deck leakage must be prevented
Key advantages
- Tough-elastic PU film bridges fine cracks and rides deck movement without cracking
- Locks broadcast quartz aggregate in place for durable, controllable slip resistance
- Watertight layer that protects the concrete and reinforcement from water and chloride ingress
- High abrasion resistance suits forklift, trolley and vehicle traffic
- Non-yellowing, colour-stable matt finish holds up under UV and headlights
- High solids (~85%) give a dense, hard-wearing cured film per coat
- Good adhesion (tensile adhesion above 1.5 N/mm) to a properly prepared body coat
- Part of a complete, warrantable Sika car-park and industrial-floor system
Limitations & considerations
- It is a seal/wearing coat, not a standalone product – it needs the correct primer and body coat beneath it
- Sensitive to application conditions: substrate moisture must be under 4% and RH under 80%, or the film can blister or bloom
- Short pot life of about 25 minutes at +20C means only mix what the crew can lay quickly
- Restricted temperature window (+10C to +30C, and at least 3C above dew point) can slow winter or monsoon programmes
- As a matt PU it is not a decorative high-gloss finish and shows wear polishing over time in high-traffic lanes
- Not intended for aggressive chemical-immersion or strong-acid duty, where a specialist chemical-resistant system is required
Selection & best practice
Treat Sikafloor-359 N as the final layer of a designed system, not a coat of floor paint. Confirm the concrete is sound, cured and dry (moisture below 4% pbw), then prime and lay the body coat and broadcast the quartz sand per the Sika build-up before sealing. Check conditions before mixing: substrate and air between +10C and +30C, relative humidity under 80%, and the substrate at least 3C above the dew point to avoid condensation and blooming. Mix Part A and Part B in the supplied 78:22 ratio, combining continuously for about two minutes to a uniform colour, and only batch what the team can apply inside the roughly 25-minute pot life. Spread at around 0.7-0.9 kg/m per layer depending on the texture and system, work wet-edge to avoid lap marks, and protect the fresh floor from water, traffic and dust until it has cured. Full mechanical and chemical resistance develops over the following days, so phase the handover accordingly.
Specifications
| Product type | 2-component, tough-elastic polyurethane seal coat |
| Finish / appearance | Coloured, non-yellowing, matt |
| Mixing ratio (A:B) | 78 : 22 by weight |
| Pack size | 32.5 kg unit (25.35 kg Part A + 7.15 kg Part B) |
| Consumption | Approx. 0.7-0.9 kg/m per layer, depending on system and texture |
| Solids content | Approx. 85% |
| Shore D hardness | Approx. 52 (7 days at +23C) |
| Tensile adhesion | Greater than 1.5 N/mm |
| Abrasion resistance | 160 mg loss (Taber CS 10 / 1000 g / 1000 cycles) |
| Pot life | Approx. 25 minutes at +20C |
| Application conditions | +10C to +30C, max 80% RH, substrate moisture under 4% pbw, at least 3C above dew point |
Industry use cases
Multi-storey & basement car parks
Non-yellowing, crack-bridging seal coat for intermediate and top decks, keeping the surface watertight over occupied levels below.
Warehousing & logistics
Abrasion-resistant wearing coat for aisles and loading docks that take constant forklift, pallet-truck and vehicle traffic.
Ramps & circulation areas
Binds broadcast quartz for reliable slip resistance on inclines and turning zones where tyres scrub hardest.
Manufacturing & industrial floors
Tough, easy-to-clean matt finish for production and handling areas exposed to oil, water and mechanical wear.
Refurbishment of existing decks
Re-seals and re-textures ageing broadcast systems, restoring skid resistance and waterproofing without full demolition.
Frequently asked questions
Is Sikafloor-359 N a standalone floor paint?
How much material do I need per square metre?
Will the colour fade or turn yellow outdoors?
What is the pot life once mixed?
What condition does the concrete need to be in?
Can Space Arc supply and apply it across India?
How we position Sika Sikafloor-359 N
Sikafloor-359 N sits at the top of the Sika car-park and industrial-floor stack as the tough-elastic seal coat, and is best specified alongside the rest of that family – a Sikafloor epoxy primer, a matching Sikafloor PU body coat, and Sika quartz broadcast sand – so the whole system carries one manufacturer’s warranty. Where the priority is a rigid, chemical-resistant industrial floor in a wet or process area rather than a flexible deck coating, our Sika epoxy self-levelling and screed options are a better fit. Across our other brands, MC-Bauchemie and Master Builders Solutions offer comparable PU and epoxy deck and flooring systems for specifiers who prefer those ranges, while Fosroc’s Nitodek and Nitoflor lines cover similar car-park and industrial-floor duties; tell us the deck detail, traffic and finish you need and we will map the closest verified system from the brands we stock.
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