Bostik Cempolay Deep Floor Levelling Compound Grey 20kg

Product Overview

Bostik Cempolay Deep Floor Levelling Compound in a 20kg bag. This high-strength, protein-free, cement-based levelling compound is designed for deep internal applications. It levels and smooths uneven subfloors, capable of building up from 5mm to 50mm in a single pour. 

The formulation combines selected cements and organic binders to produce a robust, free-flowing mortar that transforms irregular subfloors into a flat, load-bearing surface ready for a wide range of floor coverings. 

Once mixed with water, the compound develops a smooth, easily workable consistency with excellent flow and rapid hardening characteristics. 

Its protein-free composition reduces the risk of bacterial growth, making it suitable for hygiene-sensitive areas in healthcare or food preparation environments.

Features & Benefits

• Wide application thickness: Levels from 5mm to 50mm in a single application, ideal for significant height corrections and deep filling.
• High strength and durability: Creates a dense, load-bearing surface suitable for light to heavy-duty interior traffic prior to floor covering installation.
• Protein-free formulation: Prevents biological contamination, ensuring suitability in hospitals, kitchens, and other hygiene-critical areas.
• Excellent workability: Free-flowing mortar with a 15-20 minute working time for easy application and self-levelling performance.
• Rapid setting: Accepts light foot traffic after approximately 90 minutes, expediting project turnaround.
• Versatile substrate compatibility: Bonds to concrete, sand/cement screeds, stone, and properly prepared unglazed tiles.
• Underfloor heating compatibility: Suitable for use over warm-water underfloor heating systems when installed to correct specification.
• Smooth finish: Provides a high-quality, even surface for vinyl, carpet, tile, and other bonded coverings.
• Bag size - 20 kg: Supplied in 20kg units to achieve consistent water-to-powder ratio and reliable site handling.

Applications

• Levelling uneven subfloors: Corrects irregularities and undulations in concrete or screeded floors.
• Raising floor levels: Builds up internal floors to significant heights in one operation.
• Filling depressions and trenches: Ideal for filling low spots, voids, or service channels.
• Creating sloping screeds: Forms controlled gradients for drainage or transitions between floor levels.
• Smoothing over existing hard surfaces: Suitable for use over well-bonded, sound subfloors such as concrete, sand/cement screeds, stone, or unglazed ceramic and quarry tiles.
• Not suitable for: Use over wooden floors, adhesive residues, mastic asphalt, or areas subject to permanent water immersion.

Installation Guidance

• Substrate preparation: Surfaces must be clean, dry, structurally sound, and free of grease, dust, laitance, or contaminants. Mechanical preparation such as grinding or shot blasting may be required.
• Repair and inspection: Fill cracks and voids with a suitable repair mortar such as Bostik Rapid Repair Mortar and allow to dry before application.
• Environmental conditions: Maintain substrate, air, and material temperature between +5°C and +27°C; avoid draughts during curing.
• Mixing ratio: Add exactly 3.5 litres of clean, cold water per 20 kg bag. Gradually add powder to water while mixing with a heavy-duty drill (minimum 650 rpm) fitted with a mixing paddle. Mix for at least two minutes, allow to stand for one minute, then briefly re-mix.
• Application process: Pour immediately after mixing, spreading evenly with a steel trowel or gauge rake to the desired thickness. Use a spiked roller within 10–15 minutes to de-aerate and achieve a uniform finish.
• Working time: Approximately 15–20 minutes at +20°C. Do not add water to re-temper the mix once it begins to stiffen.
• Drying and curing: Protect the surface until set. Allow full drying before applying coverings — typically 24 hours per 5 mm thickness at +20°C.

Compliance & Performance

• Material composition: Cement and polymer binder blend with fine aggregates; free from protein and casein.
• Application depth: Suitable for single-pour thicknesses between 5 mm and 50 mm.
• Compressive strength: High early and final strength for domestic, commercial, and light-industrial interiors.
• Working time and trafficability: Approximately 15–20 minutes working time; accepts light foot traffic after 90 minutes at +20°C.
• Drying time before coverings: 4 hours for loose-laid coverings; approximately 24 hours per 5 mm thickness for bonded finishes such as vinyl or wood.
• Surface moisture: Ensure substrate <75%RH before installation of impervious finishes.
• Compatibility: Suitable for use over concrete, screed, stone, and other rigid mineral subfloors; not for exterior or submerged applications.
• Standards compliance: Subfloor preparation and installation in accordance with BS 8204 (Code of Practice for Concrete Subfloors).
• Important note: Always follow the manufacturer’s data sheet and safety guidance. Use appropriate PPE during mixing and application, and ensure adequate ventilation throughout the curing process.