Product Codes

  • Grey 30620342 - 20kg bag
  • White 30620343 - 4.17L polyjerry


Approx. 5m2 per bag at 2mm to 3mm depth (depending on the smoothness of the floor surface & application technique)
30620342 - 20kg bag 30620343 - 4.17 litre polyjerry
Blend of cement and latex liquid
+5°C to +25°C
Bostik SL C540 FLOW Latex Liquid
Feather edge to 20mm (bulk out above 10mm)
Up to 20 minutes after mixing (depending on ambient temperatures)
Foot traffic: approx. 1½ hours. Loose lay floor coverings: approx. 8 hours. Bonded textile floor coverings: approx. 12 hours. On non-absorbent subfloors lay floor coverings: approx. 24 hours (<3mm depth at +20°C, depending on ambient conditions)
Store and transport securely. Store for up to 6 months from date of manufacture in original, unopened packaging, clear of the ground, in cool, dry conditions within the temperature range +5°C to +25°C and out of direct sunlight. Protect from excessive drafts, frost, damp, condensation and dew.
Powder and liquid
Typically 25N/mm² after 28 days
Typically 7N/mm² after 28 days
Clean tools and equipment with warm soapy water immediately after use

Key Features

Can be used over firmly bonded adhesive residues
Excellent flow characteristics
Protein-free and low-odour


Bostik SL C540 FLOW is a two-part cementitious underlayment with an improved flow for smoothing and levelling uneven floors before laying decorative floor coverings. It has excellent workability and flow, is self-smoothing and can be trowelled to a feather edge. Bostik SL C540 FLOW can be applied over most common substrates, including concrete, sand/cement screeds, stone, anhydrite screeds, terrazzo & quarry tiles, asphalt and other solid and rigid subfloors. Bostik SL C540 FLOW should not be used over adhesive residues. As Bostik SL C540 FLOW is protein-free, it is suitable for biologically sensitive areas. The low-odour formulation makes it ideal for use in occupied buildings. The moisture tolerant formula enables Bostik SL C540 FLOW to be used to smooth rough-textured subfloors before the application of Bostik damp proof membranes in buildings incorporating a base DPM. It is suitable for use with warm water underfloor heating systems, provided a surface temperature of +27°C is not exceeded and in areas of high solar gain. It is not to be used as a wearing surface and should always be covered with a floor covering. For interior use only.

Case Study
Bostik – Flooring in Healthcare
Bostik – Flooring in Healthcare
Technical advice and quality subfloor preparation products and flooring adhesives from Bostik are said to have enabled the progress of the new hospital building.
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