Sika Sikafloor-304 W
A two-component, water-based polyurethane matt seal coat that finishes and protects Sika ComfortFloor systems with very low odour and strong non-yellowing UV performance.
What is it?
A two-part, water-based polyurethane (PUR) matt seal coat that forms the wearing top layer of Sika ComfortFloor systems, sealing the elastic PU body coat against dirt, scuffing and daily cleaning.
Where is it used?
Hospitals, clinics, schools, offices, showrooms, retail interiors and premium residential floors laid with Sika ComfortFloor PS-24, PS-64 or PS-66.
Why use it?
Its water-borne chemistry keeps odour and VOC below 140 g/l, so occupied and hygiene-sensitive spaces can be sealed with minimal disruption while gaining a durable, easy-clean matt finish that resists yellowing.
How is it applied?
Blend Part A and Part B at 80:20 by weight, dilute with about 5% water, rest 10 minutes, then roller-apply a thin uniform coat over the cured ComfortFloor body coat within the 30-minute pot life at +20 C.
About Sika Sikafloor-304 W
Sikafloor-304 W is the finishing seal coat in the Sika ComfortFloor family of seamless elastic polyurethane floors. Where the PS-24, PS-64 and PS-66 systems provide the coloured, comfortable, self-smoothing body, Sikafloor-304 W is the thin protective skin rolled on top of them. It is a two-component product supplied as a 7.5 kg ready-to-mix unit, with 6.0 kg of white Part A resin and 1.5 kg of yellowish Part B hardener, mixed at a strict 80:20 ratio by weight and let down with roughly 5% water. The chemistry is fully water-based, so it carries very low odour and a VOC content below 140 g/l for the ready-to-use product, which is why specifiers reach for it in occupied buildings rather than solvent-borne alternatives.
For contractors working in Indian hospitals, schools and corporate interiors, the appeal is practical. The cured film is silky-matt, so it hides minor foot-scuff and glare far better than a gloss seal, and it cleans down with routine wet mopping. It carries the CE mark against EN 1504-2 and EN 13813, holds a fire classification to EN 13501-1, and has been independently assessed for biological resistance to ISO 846, all of which matter when a consultant is signing off a healthcare or education floor. Space Arc Engineering supplies genuine Sika material and applies it as part of a complete ComfortFloor build across Delhi NCR and Pan-India, so the seal coat, body coat and primer come from one accountable source.
The technical insight
The reason Sikafloor-304 W behaves so differently from a solvent seal comes down to how a water-borne polyurethane dispersion films. The two components are pre-reacted PU chemistry carried in water; once mixed at 80:20 and diluted, the polymer particles coalesce as the water evaporates and the isocyanate and polyol functionality cross-links into a continuous, flexible film. That cross-linking is what gives the coat its chemical resistance and its non-yellowing, UV-stable surface, while the water carrier is what keeps odour and VOC down. Because film formation depends on moisture leaving the coating, the environment during curing is critical: relative humidity must stay at or below 75%, the substrate and fresh floor must sit at least 3 C above dew point to prevent condensation blooming, and the space needs genuine fresh-air ventilation to carry off the evaporating water. Get those conditions right and the matt film sits tight over the elastic ComfortFloor body coat, moving with it rather than cracking; get them wrong and you risk a hazy, under-cured surface. This is also why the product is restricted to experienced applicators.
Where it is used
- Final matt seal coat over Sika ComfortFloor PS-24 seamless elastic PU flooring
- Wearing top layer for ComfortFloor PS-64 sound-insulating floor systems
- Protective seal for ComfortFloor PS-66 resilient PU floor coverings
- Low-odour sealing of occupied hospital wards, clinics and diagnostic areas
- Hygienic floor finishing in schools, laboratories and childcare interiors
- Matt, anti-glare sealing of offices, showrooms and retail floors
- Sealed elastic flooring for premium residential apartments and villas
- Non-yellowing top coat where daylight and UV exposure would yellow a lesser seal
Key advantages
- Water-based chemistry with very low odour, suitable for occupied buildings
- VOC content below 140 g/l for the ready-to-use product
- Good UV resistance and non-yellowing, holding colour under daylight
- Silky-matt finish that masks scuffing and reduces glare
- Easy to clean and maintain with routine wet mopping
- CE marked to EN 1504-2 and EN 13813 with an EN 13501-1 fire classification
- Independently assessed for biological resistance to ISO 846
- Tools clean up with water immediately after use, simplifying site logistics
Limitations & considerations
- Only a seal coat, not a standalone floor; it must be applied over a cured Sika ComfortFloor body coat
- Short pot life of about 30 minutes at +20 C, so only mix what can be laid quickly
- Curing depends on humidity staying at or below 75% and the floor being at least 3 C above dew point
- Freshly applied film must be protected from water, damp and condensation for at least 7 days at +20 C
- A thin seal will not hide substrate unevenness or trapped dirt, so preparation must be thorough
- Only electric warm-air blowers may be used for heating; gas, oil or paraffin heaters release moisture and CO2 that spoil the finish
- Restricted to experienced professional applicators
Selection & best practice
Confirm the substrate is clean, dry and sound with a pull-off strength of at least 1.5 N/mm2, and that the ComfortFloor body coat has cured within its own overcoating window. Check substrate moisture, relative humidity and dew point before opening a unit. Stir Part A, add all of Part B, mix for three minutes with a low-speed stirrer at 300 to 400 rpm, decant into a clean container and mix again, then dilute with about 5% water and rest the material for ten minutes to release entrained air. Roller-apply a thin, uniform coat with a short-pile nylon roller (or airless spray), keeping a wet edge for a seamless finish, and work within the 30-minute pot life at +20 C. Maintain ambient and substrate temperature between +10 C and +30 C, keep humidity at or below 75%, and provide fresh-air ventilation to remove evaporating moisture. Overcoat only within the stated window, protect the fresh floor from water for seven days, and clean tools with water immediately after use.
Specifications
| Chemical base | 2-part water-based polyurethane (PUR) |
| Packaging | 7.5 kg ready-to-mix unit (Part A 6.0 kg + Part B 1.5 kg) |
| Mixing ratio | Part A : Part B = 80:20 by weight; dilute with ~5% water |
| Mixed density | ~1.07 kg/l at +23 C (diluted with 5% water) |
| Finish / gloss | Silky-matt (60 degrees <10, 85 degrees <55, ISO 2813) |
| Pot life | ~50 min at +10 C, ~30 min at +20 C, ~20 min at +30 C |
| Application temperature | +10 C to +30 C ambient and substrate; RH 75% max; min 3 C above dew point |
| Overcoating time at +20 C | Min 16 hours / max 3 days |
| Standards | CE marked to EN 1504-2 and EN 13813; VOC <140 g/l; fire class EN 13501-1 |
Industry use cases
Healthcare
Seals ComfortFloor systems in hospital wards, clinics and diagnostic rooms where low odour during application and an easy-clean, hygienic surface are non-negotiable.
Education
Provides a matt, non-yellowing, low-glare finish for school corridors, laboratories and childcare floors that stays presentable under heavy foot traffic.
Corporate and retail
Delivers a durable anti-glare seal for offices, showrooms and retail interiors, protecting the coloured ComfortFloor body coat from daily scuffing.
Premium residential
Finishes seamless elastic PU floors in high-end apartments and villas with a soft matt surface that resists yellowing near large windows.
Laboratories and cleanrooms
Its ISO 846 biological-resistance assessment and dense, cleanable film suit controlled environments that demand a low-VOC, easily maintained floor.
Frequently asked questions
Can Sikafloor-304 W be used on its own as a floor coating?
Why choose a water-based seal over a solvent-borne one?
What is the coverage of one 7.5 kg unit?
How long before the floor can take traffic?
What conditions are needed during application?
Does Space Arc supply and apply Sikafloor-304 W across India?
How we position Sika Sikafloor-304 W
Sikafloor-304 W is the finishing layer of a system, so it is best specified alongside its Sika partners: the ComfortFloor PS-24, PS-64 or PS-66 body coats it seals, over an appropriate Sika epoxy primer. Where a project needs a hard-wearing epoxy floor instead of an elastic PU one, Space Arc can point you to Sikafloor epoxy systems from the same brand. Across our other lines, teams that want a water-based PU seal on a cementitious or concrete floor rather than a ComfortFloor build often look at Fosroc Nitocote PUW100, and for heavy-duty PU-cement kitchen and food-plant floors we also carry MC-Bauchemie and Fosroc options.
Fosroc Nitocote PUW100 — A specifier may choose this water-dispersed PU sealer when the floor is a cementitious or concrete slab needing a pigmented, easy-clean seal, rather than a Sika ComfortFloor build where Sikafloor-304 W is the matched top coat.
Related Industrial Flooring products
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