About STP ShaliFloor SL UL 1C-P

ShaliFloor SL UL 1C-P is STP Limited’s premium-grade, single-component cementitious self-levelling underlay. It is supplied as a dry, factory-blended powder of special cements, graded fillers and polymers; on site you add only clean water and mix to a free-flowing slurry that spreads and finds its own level with minimal trowelling. The result is a smooth, flat, closed surface that corrects the small undulations, trowel marks and level differences left behind by concrete slabs, sand-cement screeds and old tiled floors. It is applied in thin sections, typically 2-10 mm in a single pour, and is intended as a preparation layer beneath a finish rather than as an exposed floor in its own right.

What sets the 1C-P apart from the standard ShaliFloor SL UL 1C-R is drying speed. The “P” is the premium, fast-drying grade, formulated so the underlay reaches a walk-on state in roughly one to two hours and accepts the subsequent floor covering sooner. On a live fit-out, that difference is the whole point: a levelling layer that holds up the flooring contractor by a day is expensive, while one that lets tiling, vinyl or a resin system follow the same shift protects the programme. Because it is single-component, there is no resin-to-hardener ratio to get wrong on site, no mixing skill beyond adding the right volume of water, which makes it forgiving for larger crews working at pace.

The technical insight

The performance comes from the cement chemistry and particle packing rather than from any resin binder. A blend of special cements and fine graded fillers is designed so that, at the correct water dose, the mix is fluid enough to flow and de-air yet cohesive enough not to bleed or segregate; that balance is what gives a genuinely flat, closed surface instead of a rough or pinholed one. Polymer additives improve cohesion, adhesion to the primed substrate and early strength gain, so the layer develops usable hardness quickly, which is what makes the fast walk-on time possible. The self-levelling behaviour is quantified by flow tests in the EN 12706 family used for this class of underlay; the fresh material spreads to a controlled diameter and settles level under its own weight. Hardened performance is modest but appropriate for a preparation layer, with compressive strength around 25 MPa and flexural strength around 4 MPa at 28 days. Priming is not optional detailing, it is central to the mechanism: the primer seals a porous or dusty substrate so the fluid mix does not lose water into it and flash-set, and it promotes the bond that stops the thin section from de-bonding under the finished floor.

Where it is used

• Levelling and smoothing uneven interior concrete slabs and sand-cement screeds before a floor covering
• Fast-track retail fit-outs and commercial renovations where the floor must be ready the same day or next shift
• Hospitals, clinics and schools where occupied areas allow only short flooring downtime
• Floor preparation beneath vinyl sheet, LVT, carpet, ceramic tiles or thin resin coatings
• Skim-levelling over sound, well-bonded existing tiles once suitably primed
• Correcting minor falls, trowel ridges and level differences left by the slab
• Preparing bases in offices, showrooms and hospitality interiors ahead of the final finish
• Airport, transit and large commercial floors requiring a flat, tolerance-controlled base

Key advantages

• Single-component, water-only mixing removes the risk of a wrong resin-to-hardener ratio on site
• Premium fast-drying grade allows the floor covering to follow sooner than the standard 1C-R
• Walk-on in roughly 1-2 hours keeps multi-trade fit-out programmes moving
• Free-flowing, self-levelling action gives a smooth, flat, closed surface with minimal labour
• Thin-section versatility from 2-10 mm in a single pour suits both feathering and modest build-up
• High early strength gain supports quick progression to the next trade
• Compatible with the wider ShaliFloor finish and coating systems for a coordinated build-up
• Backed by STP Limited, an established Indian construction-chemicals manufacturer with pan-India supply

Limitations & considerations

• A preparation underlay only, not a final wearing or exposed surface, and must be covered by a finish
• Intended for interior sub-floors, not for external or continuously wet or immersed areas
• Thin-section product limited to about 2-10 mm per pour, so deep re-profiling needs a thick-bed system instead
• Short pot life once mixed means only what can be poured promptly should be batched
• Substrate must be sound, clean and correctly primed, poor preparation causes de-bonding or pinholing
• Water dosage must be controlled, over-watering causes bleed, weakness and a dusty surface

Selection & best practice

Specifications

Industry use cases

How we position STP ShaliFloor SL UL 1C-P

ShaliFloor SL UL 1C-P sits at the fast-track end of STP’s ShaliFloor underlay family. Within the same brand, the standard ShaliFloor SL UL 1C-R covers projects where drying speed is less critical and budget matters more, while ShaliFloor SL UL 3 EC, a three-component epoxy-cement underlay, is the choice where the base is damp or must carry higher-strength resin flooring. Once the level base is set, STP’s ShaliFloor resin toppings and coatings provide the wearing finish over it. Across Space Arc’s other brands, Fosroc Nitoflor Levelcrete is the natural counterpart when the correction is too deep for a thin-section product. As an authorised distributor and applicator across Delhi NCR and pan-India, Space Arc can match the right underlay to your substrate condition, finish system and programme rather than defaulting to a single grade.

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