Flexcrete Cemprotec EF Primer is a single component acrylic and styrene acrylic copolymer solution with high penetration into the substrate. It stabilises and seals cementitious or asphalt substrates and prevents outgassing in Flexcrete waterproof cementitious coatings. This includes when used as a hybrid system with resin-based coatings and screeds applied over cementitious waterproofing or levelling coats.

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• Pack Contents
• Preparation - Concrete
• Preparation - Asphalt
• Placing
• Tape Joints and Overlaps
• Cleaning and Storage
• Application Top Tips
• Technical Data

Pack Contents

Cemprotec EF Primer is supplied in 5 litre and 25 litre units.

Preparation - Concrete

New surfaces generally only require a minimum of 1 day cure prior to treatment. Surface laitance and any curing membrane must be removed by blast cleaning techniques or acid etching. Flexcrete repair materials and polymer modified toppings may also be overcoated after 1 day.

Existing surfaces should be inspected thoroughly. The areas to be treated must be free from all unsound material including dust, oil, grease, organic growth or any previous surface treatments. Smooth surfaces should be roughened. This can be achieved by using portable shot-blasting equipment such as Blastrac or other approved blasting or scarifying techniques. The substrate should be prepared to leave a surface texture.

Any remaining contamination from oil and grease must be completely removed with a proprietary degreasant. To remove heavy contamination, it may be necessary to use hot compressed air equipment, flame spalling or steam cleaning techniques.

All previous repair materials, patches, etc. which are unsound should be removed. Static cracks, voids, defects, etc. should be cleaned out prior to making good using an appropriate Flexcrete repair mortar. Final high pressure water jetting is recommended to remove any remaining debris to leave a thoroughly clean, dust free open textured surface.

The prepared substrate should be thoroughly soaked with clean water until uniformly saturated without any standing water.

The compressive strength of the parent concrete should be minimum 20 MPa.

Preparation - Asphalt

Assuming that there are no defects, new asphalt may be treated after 72 hours, although ideally it should be left longer to allow any shrinkage to occur. Surfaces should be wiped with a proprietary solvent to remove any surface contamination and allowed to dry prior to treatment.

Existing asphalt must be inspected for defects. Any areas which have lost adhesion or blistered must be re-adhered or replaced. Any areas exhibiting sagging or slumping should be ironed out or replaced. Large cracks must be cleaned out and filled using a compatible material or heated and re-sealed. Do not overheat. If necessary, patch repairs should be carried out and allowed to cure prior to subsequent coating.

The surface should be prepared with enclosed shot blasting equipment or a surface planer or scaler to provide a good texture and to ensure that all surface contaminants are removed. Oil and grease contamination should be removed using powerful detergents in combination with high pressure water jetting. Areas of severe contamination should be cut out and filled with a Flexcrete repair mortar.

Clean down all surfaces using high pressure water at a minimum of 2000 psi to provide a clean, contamination free surface for treatment. Allow surfaces to dry before continuing.

Placing

Cemprotec EF Primer should be poured onto the prepared surface and spread using a roller or a brush. Allow to become a transparent blue colour before continuing, typically 30-90 minutes depending on temperature. If not overcoated within 7 days, the primer must be mechanically removed by blast cleaning or hand held power tools before re-application as above.

If areas are subjected to ponded water during the 7 day overcoat window, inspect for softening and degradation. Mechanically remove any affected primer using blast cleaning or hand held power tools and reapply.

Note - do not add water or other materials to this product.

Coverage

Concrete:

• Porous: 3 m²/litre
• Normal quality (20-30N/mm²): 5 m²/litre
• Dense/power-floated: 7 m²/litre

Cemprotec Levelling Coat: 10 m²/litre

Asphalt: 7 m²/litre

Cleaning and Storage

All tools should be cleaned with water immediately after use.

Materials can stored be for 12 months in dry, frost free conditions away from heat.

Application Top Tips

1. Rough, porous or irregular substrates will reduce coverage
2. For roller application use short pile rollers or equivalent
3. Low temperatures and high humidity will extend drying times
4. Clean brushes and rollers occasionally during use
5. Cold Weather Working (See separate Guide)
• Do not apply below:
• ≥3ºC on a rising thermometer
• ≥5ºC on a falling thermometer
6. Do not use any product which has been frozen
7. Protect from prolonged storage at ≥40°C

Technical Data

The properties given above are obtained from laboratory tests: results obtained from on-site testing may vary according to site conditions.