Skim Coat

Rapid Set® Skim Coat: Patching, Skim Coating, and Underlayment

Use Rapid Set® Skim Coat to save time and easily repair, level and smooth concrete substrates prior to the installation of floor coverings. Skim Coat is used for floor underlayments, concrete repairs, patching and skim coating. It is a high bond strength, fast-curing, smooth (unsanded), hydraulic cement-based material for use on interior and exterior projects. Skim Coat has excellent bond strength and is resistant to mold and mildew. No primer or curing compound is necessary.

Apply and finish from featheredge to 1-inch deep. Top with flooring such as VCT, sheet vinyl, carpet, tile, pavers within 1 hour and with an epoxy in 16 hours. One 20-pound bag has skim coat coverage of 66.6 square feet at 1/8-inch deep or 33.4 square feet at ¼-inch deep.



The Datasheet explains the performance and technical characteristics of Rapid Set® Skim Coat.  It also shows how to use Skim Coat (i.e. surface preparation, mixing, placement and curing).

The Spanish Datasheets are also available.


The Safety Data Sheet (SDS) outlines information and procedures for handling and working with Rapid Set® Skim Coat.  It includes physical and chemical property information, potential hazards, emergency procedures and CTS’s contact information.


The Specification gives a detailed statement explaining the type of jobs to specify Rapid Set® Skim Coat for, the scope of work, thicknesses, performance requirements and usage.

Standard Practices

Q: Where can I use Rapid Set® Skim Coat?
A: Rapid Set® Skim Coat can be used as an underlayment and cosmetic patching. Please contact your local CTS Cement representative for more information on other applications.

Q: Can Rapid Set Skim Coat be used as a wear surface?
A: Rapid Set Skim Coat cannot be used as a wear surface. It will not support car or forklift traffic.

Q: How should the surface be prepared?
A: Surface should be mechanically abraded by scarifying, grinding, shot-blasting, or other approved methods. Remove all loose particles from the surface. Surface must be porous, not be contaminated by oil, bond breakers, paint, acids, dirt or other materials that prevent a good bond.

Q: How much working time do I have with Rapid Set Skim Coat?
A: At temperatures of 70°F, the working time of Rapid Set Skim Coat is approximately 20-30 minutes. Cold materials and water will slow down the set time, while warm materials and water will speed up the set time.

Q: How thick can I apply Rapid Set Skim Coat?
A: Rapid Set Skim Coat can be applied in thicknesses from featheredge up to 1-inch deep

Q: What type of primer should I use with Rapid Set Skim Coat?
A: Rapid Set Acrylic Primer is specially formulated for compatibility with Rapid Set Skim Coat.

Q: Do I need a primer? When would I use a primer?
A: Primer is not needed for Rapid Set Skim Coat application. A primer will be needed if Rapid Set Skim Coat is applied in multiple lifts. Multiple lifts will require primer to be used between lifts. Primer may be needed for porous substrates.

Q: Can a sealer be used with Rapid Set Skim Coat? What kind of sealer should I use?
A: Yes, Rapid Set Skim Coat can be compatible with sealers. Water based sealers are recommended for use with Rapid Set Skim Coat. Other sealers may be used, please contact your local CTS Cement Representative for more information.

Q: How many FLOW Control® packets can I use per 20-lb bag of Rapid Set Skim Coat?
A: For a 20-lb bag of Rapid Set Skim Coat, only one packet may be used.

Q: How many SET Control® packets (0.9 oz, 25 grams) can I use per 20-lb bag of Rapid Set Skim Coat?
A: For a 20-lb bag of Rapid Set Skim Coat, only one packet may be used.

Jobs & Applications

Miami Art Gallery, Miami, FL, CRS (micro topping on floor)

Leed Product Evaluation

TechnicalSupportWhether you’re working on a time-sensitive project and need answers, or evaluating and choosing the right cement products, or looking to achieve specific results, we are here to help. Get answers to your questions from our technical support team. Find and download useful information from our website. Ask us to help get your construction team up to speed by requesting a jobsite demonstration or educational seminars.

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