Surface Retarders

Product Description 

Surface Retarders offer unmatched reliability and control for exposed aggregate finishes. The beauty and durability of this high quality finish can be seen in landmarks worldwide: the grounds of the U.S. Capitol; Yamoussoukro Basilica, Africa; and the European Parliament, to name a few.

GCP Produits de Construction S.A.S., a French division of GCP, brings over 40 years of experience in the surface retarder market, creating a range of products with an unprecedented level of control for depth-of-etch. This allows a uniquely controllable selection of surface finishes to add beauty to architectural concrete.

GCP has been serving the needs of the international construction industry with products that improve strength and durability. The GCP combination of innovative products, sophisticated research and development and technical service and support at the job site deliver added value that is unmatched in the industry.

Product Uses 

Surface Retarders provide a comprehensive range of effect, from a light sand finish up to full exposure of 11⁄4 in. (32 mm) aggregate. The products are designed for use on cast-in-place walls, residential driveways, pool decks, golf course cart paths, sidewalks or large plaza decks and precast concrete. Review the Surface Retarder Guide below to determine the product which best matches your job requirements.

Product Advantages 

  • Comprehensive range of etch depth
  • Excellent depth-of-etch control
  • Improves flexibility of when you can wash
  • Products available both for in-form and surface applications
  • VOC compliant
  • Easy application
  • Excellent coverage rates
  • Short drying times

Product Function 

Each product creates a unique degree of reaction to produce the effect on the surface mortar. The retarding chemicals diffuse into the paste, due to the normal porosity of cement in the first hours of curing, and slow down the cement hydration reaction. During the next 16–72 hours of curing, the bulk concrete hardens except where the matrix cement has been retarded. The retarded surface cement is then removed by water or sandblasting, revealing the aggregate in the concrete mix.

Surface Retarder Guide

Top Surface Retarders

Product No. of Etches Type of Base Product Characteristics Resistance to Abrasion (concrete placing time) Heat Resist. Application Methods Approximate Coverage and Drying Time Release Required
 TOP-CAST® 11 Water A film-forming top surface retarder which prevents accelerated evaporation. Saves time by eliminating the need for covering the surface. Designed for large paving and hollow core applications. NA Up to 140°F (60°C) Low pressure, garden-type sprayer 200–300 ft2/ gal (4.9–7.4 m2/L) NA

In-Form Retarders

Product No. of Etches Type of Base Product Characteristics Resistance to Abrasion (concrete placing time) Heat Resist. Application Methods Approximate Coverage and Drying Time Release Required
Pieri® EURO-TARD 11 Solvent* An in-form retarder, unique in not requiring an undercoating release. The depth-of-etch is highly uniform. The retarded matrix is designed not to transfer to the concrete and is easily brushed from the form. Good 30–40 minutes Up to 150°F (65°C) Brush or roller: 2 light coats Spray: 1 full-bodied coat 350-400 ft2/ gal (8.6-9.8 m2/L) 10 minutes NA
Pieri® DURO-TARD 9 Solvent* An in-form retarder, unmatched for abrasion resistance. Recommended for vertical surfaces up to 10 ft, for spun poles and for multi-batch panels, where extended placing times are required. Excellent 45–60 minutes Up to 150°F (65°C) Brush or roller: 2 light coats Spray: 1 full-bodied coat 250–300 ft2/ gal (6.1–7.4 m2/L) 10 minutes WMR
Pieri® VMR NA Alcohol An undercoat for use with DURO-TARD. Ensures transfer of retarder to the cast concrete. Dries fast. Reduces or eliminates form clean-up. NA NA Brush or roller 400-500 ft2/ gal (9.8-12.3 m²/L) 20 minutes NA

*Complies with U.S. E.P.A. Volatile Organic Compound Emission Standards for Architectural Coatings

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We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right.

PIERI, and TOP-CAST are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

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GCP Applied Technologies Inc., 62 Whittemore Avenue, Cambridge, MA 02140 USA.

In Canada, 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6.

This document is only current as of the last updated date stated below and is valid only for use in the United States. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on www.gcpat.com. Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2018-11-29

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