Sherwin-Williams Floorcoating Cemcrete Primer

4.7 Kilograms
£62.70 (inc VAT)
Special Offer

  • Single Pack
  • Easy to Use & Apply
  • Bonds to Cementitious Substrates
  • Can be Used as a Dust Sealer
  • Water & Alkali Resistant


Sherwin-Williams Floorcoating Cemcrete Primer

Efficient concrete primer

Cemprime is a single pack copolymer emulsion designed purposely as a primer for porous substrates. It stabilises and seals substrates effectively promoting adhesion that will allow self-smoothing compounds to be applied directly. It can also be used as a dustproof coating when applied as a tight coat by squeegee or roller depending on texture, and finish. Once dry R.S. Cemprime produces a water and alkali resistant polymer layer which both bonds to and strengthens the surface.


• Single pack

• Easy to use and apply

• Provides effective bonding to cementitious substrates

• Can be used as a dust sealer

• Water and alkali resistant

Recommended Uses

• As a primer for pumped industrial screeds

• Ideal for porous substrates such as concrete and sand/cement

• As a temporary surface sealer and dust proofer


New Concrete Floors:

New concrete must be clean, sound, dry, fully cured and surface laitance removed by vacuum enclosed shot blasting or mechanical grinding, a minimum strength of 25N/mm2 is required.

Existing Concrete Floors:

Remove all dirt, oil, grease, old paint or any other surface contaminants by vacuum enclosed shot blasting, scarifying or mechanical grinding. Fats, oils or greases must be removed by mechanical means and detergent washing and make sure all residue of detergent is washed and removed by rinsing with clean water. Local repairs should be carried out using Resupatch or Resuscreed 45.

Existing Floors (previously coated):

All previous coatings and loose floor paints must be removed by mechanical preparation as described in the above section and primed as specified. If the old resin flooring cannot be removed, then please consult with our technical team for advice on intercoat adhesion and suitability, as it may not be compatible with existing floor coating.

Where R.S. Cemprime is applied to masonry/concrete surfaces, care must be taken to ensure that surface preparation is thorough but does not disfigure the surface.


The ambient temperatures of the area and substrate should not be allowed to fall below 10°C throughout the application and the curing period. Where possible it is recommended that the application area is  heated to a minimum temperature of 15°C and time is allowed for the ambient and substrate temperature to stabilise prior to installation.

R.S. Cemprime can be applied by squeegee, brush or roller and worked well into the surface, at a rate of 5 m2 /l. Open, highly porous substrates may require a second application to ensure the formation of a suitable surface film to provide a bond. Rates of coverage may vary substantially dependant on the surface preparation and finish of the concrete, rates given assume a shot blasted surface with medium porosity. Once applied and dry it will not re-disperse in water.

On highly porous surfaces, or when used as a dust proofer, a very dilute (1:1 with water) wash may be applied to obtain maximum penetration Once dry this should then be followed by an application of the standard material (neat) to the surface to build the film thickness.

N.B. R.S. Cemprime is not suitable for non-porous surfaces.

Full product data sheets and safety data sheets are available on request.


Product: Cemprime
Finish: Semi-gloss
Recommended thickness range: 200 to 250 microns WFT per coat
Colour: Clear (when dry)
Products required for this system
Primer: R.S. Cemprime
System: As per specification
Surface Seal: As per specification

Product Information

System Thickness
200-250 microns WFT 46-58 microns DFT
*Coverage rate is calculated based on a sealed and smooth surface and may vary based on the substrate roughness and other conditions.
Solids Content by Weight 26%
Pack Sizes 5 Litres and 25 Litres
Pack Make Up 1 x Base (Single pack material)
Shelf Life 36 months (Base) in unopened containers
Storage Keep out of direct sunlight. Store in a dry place, between 15°C- 30°C. Product is not freeze thaw

Revised 07/2018 Issue 1—REF : CEPR
Coverage Rate
5 Litres will cover 25m2
@ 200 microns wet film thickness.
*Coverage rate is calculated based on a sealed and smooth surface and may vary based on the substrate roughness and other conditions.
Pot Life N/A
Recoating Intervals 6 hours or once surface has lost tackiness
Light Traffic 24 hours
Full Traffic 72 hours
Full Chemical Cure 7 Days

Category Guide
FeRFA Category : 1

Slip Resistance Dry N/A
Method BS7976 pt1-3 2002
The slip resistance of a floor surface can vary as a result of the installation process, conditions at the time of application and subsequent traffic. Inappropriate cleaning or maintenance can adversely affect performance. For further advice on potential wet areas please consult our technical sales team.

Bond Strength 1.8 N/mm2
Method BS EN 13892-8:2003

Temperature Resistance Tolerant of temperatures up to 50oC

VOC Life Expectancy Dependant on the floor system


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