STP ShaliFloor SL UL 3 EC
A three-component, water-based epoxy-cement self-levelling underlay engineered to take an epoxy or PU floor over concrete that is still holding moisture.
What is it?
A 3K (epoxy resin + hardener + cementitious filler) water-based self-levelling underlay from STP, formerly sold as ShaliCem Floor, laid 1.5-3 mm thick to create a hard, jointless base for industrial floor coatings.
Where is it used?
Ground-floor and basement slabs in paper mills, dairies, breweries, fertiliser and petrochemical plants, automobile factories, power houses and bottling lines where the concrete is damp or holds residual moisture.
Why use it?
Unlike pure-epoxy underlays that blister on damp slabs, its cementitious component tolerates moisture, builds very high early strength (40-50 N/mm2 compressive) and gives an epoxy or PU topcoat an excellent bond.
How is it applied?
Prime with ShaliPrime 2EC at 300 g/m2, mix components A, B and C to a lump-free slurry, spread by notch trowel to 1.5-3 mm and de-aerate with a spiked roller.
About STP ShaliFloor SL UL 3 EC
STP’s ShaliFloor SL UL 3 EC solves a problem every flooring contractor in India runs into: the slab is not dry, but the schedule will not wait. Conventional solvent-free epoxy underlays demand a bone-dry substrate with moisture below roughly 4 percent, and when they are forced onto a damp floor they osmotically blister and debond within weeks. This product, previously marketed as ShaliCem Floor, sidesteps that failure mode by pairing a water-based epoxy resin and hardener with a selected cementitious filler. The cement chemistry is comfortable with water, so the underlay cures and gains strength even while the slab below is still giving up moisture, and it leaves a hard, dense, jointless surface ready to receive almost any epoxy or polyurethane finish.
It is supplied as a three-part kit in a single 20 kg carton holding Component A (resin), Component B (hardener) and Component C (cementitious filler), so there is no site batching of separate bags and liquids. The finished underlay reaches 40-50 N/mm2 compressive strength and bonds to concrete at around 7 N/mm2, which is why specifiers reach for it in genuinely heavy-duty settings rather than as a cosmetic smoother. Applied between 1.5 and 3 mm, it both levels minor undulations and gives the topcoat a mechanically sound, moisture-managed platform. For Delhi NCR and pan-India projects, Space Arc supplies it as part of a complete build-up alongside the matching primer and finish coats.
The technical insight
The performance comes from a deliberate marriage of two curing systems. A water-based epoxy dispersion supplies adhesion, chemical resistance and toughness; the Portland-cement-based filler supplies hydraulic set and, critically, water tolerance. Because the cement phase consumes and binds free water as it hydrates, the underlay does not rely on the slab being dry to develop strength, and it is far less prone to the osmotic blistering that destroys solvent-free epoxy screeds over damp concrete. That is also why STP still specifies substrate discipline: minimum M25 concrete at least two weeks old, a pull-off strength of at least 1.5 N/mm2, floor gradient under 5 percent, and a topcoat only applied once the underlay’s own surface moisture has fallen below 4 percent. The very high early strength – foot traffic in 24 hours and overcoatable at 24 hours at 27 degrees C – lets the trade above start sooner, while full cure and design strength arrive over 28 days like any cementitious system. In effect the product buys you the moisture tolerance of a cementitious screed and the bond, hardness and chemical resistance of an epoxy in one 1.5-3 mm lift.
Where it is used
- Damp or moisture-retaining ground and basement slabs that cannot be fully dried before flooring works begin
- Underlayment beneath epoxy and polyurethane floor coatings, screeds and self-levelling toppings
- Paper mills and pulp-handling areas with constant wet processes
- Dairies and breweries where wash-down water keeps floors damp
- Fertiliser plants and petrochemical facilities needing a chemically resistant base
- Automobile manufacturing plants and assembly bays under heavy traffic
- Power houses and bottling plants requiring a hard, jointless monolithic base
- Re-profiling and levelling of uneven industrial concrete before a finish coat
Key advantages
- Tolerates damp substrates, so flooring can proceed on slabs that would blister a solvent-free epoxy underlay
- Extremely high early strength, with foot traffic and overcoating both possible after 24 hours at 27 degrees C
- High compressive strength of 40-50 N/mm2 for demanding industrial loads
- Strong bond to concrete of about 7 N/mm2, giving the topcoat a reliable anchor
- Forms a jointless, monolithic surface that is easy to clean and maintain
- Good chemical resistance suited to process industries
- Acts as a universal base for virtually any epoxy or PU coating or flooring
- Convenient single 20 kg three-part carton with no separate site batching
Limitations & considerations
- It is an underlay, not a finished wearing surface; it must be topcoated with an epoxy or PU system
- Short pot life of 10-15 minutes at 27 degrees C means only small, quickly workable batches should be mixed
- Requires a matching primer (ShaliPrime 2EC at 300 g/m2) and correct surface preparation to perform
- Concrete must be at least M25 grade, minimum two weeks old, with pull-off strength of at least 1.5 N/mm2 and gradient under 5 percent
- Off-white only; final colour and aesthetics come from the topcoat, not this layer
- Application window is 15-35 degrees C, so very hot or cold site conditions need managing
Selection & best practice
Start with mechanical preparation – grind or shot-blast the slab, then remove all dust, laitance, oil, grease and old paint by wire brushing or compressed air, and confirm the substrate meets the M25 / two-week / 1.5 N/mm2 pull-off / sub-5-percent-gradient checks. Prime with ShaliPrime 2EC at 300 g/m2 and let it dry for 4-6 hours. Mix Component A first on a slow-speed drill, add Component B and stir for about a minute, then blend in Component C to a homogeneous, lump-free slurry; do not add extra water and let entrapped air settle out before laying. Spread with a notch trowel to the target 1.5-3 mm and pass a spiked roller across the wet material to release air bubbles, taking care not to dwell so long that the spikes leave permanent marks. Because pot life is only 10-15 minutes, mix in small batches you can place immediately. Allow 24 hours before foot traffic or overcoating at 27 degrees C, and only apply the topcoat once surface moisture reads below 4 percent. Operatives should wear goggles and gloves and wash with warm soapy water after handling.
Specifications
| Product type | 3K water-based epoxy-cement self-levelling underlay |
| Composition | Component A resin + Component B hardener + Component C cementitious filler |
| Colour | Off-white |
| Theoretical coverage | 4.5 kg/m2 at 2 mm (varies with surface condition) |
| Recommended DFT | 1.5 to 3 mm |
| Compressive strength | 40-50 N/mm2 |
| Flexural strength | 7-12 N/mm2 |
| Bond strength to concrete | 7 N/mm2 |
| Pot life | 10-15 minutes at 27 degrees C |
| Overcoating interval | 24 hours at 27 degrees C |
| Curing | Foot traffic after 24 hours; full cure after 28 days |
| Packing / shelf life | 20 kg carton (A, B and C); 9 months unopened |
Industry use cases
Paper and Pulp Mills
Provides a moisture-tolerant, chemically resistant base in permanently wet process areas where the slab never fully dries, ready to carry a durable epoxy topcoat.
Dairies and Breweries
Handles the constant wash-down and thermal cycling of food and beverage plants, forming a hard, jointless underlay that keeps the finished floor bonded and hygienic.
Fertiliser and Petrochemical Plants
Delivers good chemical resistance and 40-50 N/mm2 compressive strength as a base beneath resin coatings in aggressive process environments.
Automobile and Power Plants
Its very high early strength lets heavy manufacturing and power-house floors return to traffic within 24 hours, minimising shutdown time during refurbishment.
Bottling Plants
Creates a level, monolithic platform on damp ground-floor slabs so a food-safe PU or epoxy finish can be laid without blistering.
Frequently asked questions
Can ShaliFloor SL UL 3 EC really be laid on a damp concrete slab?
Is this a finished floor or does it need a topcoat?
How much do I need per square metre?
What primer and preparation does it require?
How soon can we use the floor and apply the next coat?
What is the pack size and shelf life?
How we position STP ShaliFloor SL UL 3 EC
Within the STP ShaliFloor range, this underlay is the moisture-tolerant foundation of the build-up: pair it with the ShaliPrime 2EC primer it specifies, then finish with an STP epoxy or PU self-levelling topping such as the ShaliFloor SL TC or SL EPU toppings for the wearing coat. Where the slab is dry and a conventional resin underlay is acceptable, STP’s solvent-free epoxy self-levelling systems are the lower-cost route. Space Arc can also supply equivalents from our other flooring brands – MC-Bauchemie and Master Builders Solutions epoxy floor systems, or Sika damp-tolerant floor solutions – when a project is specified around a particular manufacturer. Talk to our team for a full moisture-managed floor specification rather than a single product.
Fosroc Nitoflor SL2050 — Specify the Fosroc route when the project calls for a Fosroc-warranted floor build-up – SL2050 is a water-based, damp-tolerant self-levelling epoxy that plays the same moisture-managed role over concrete that is not fully dry.
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