The ARDEX MC RAPID is a one-coat, 100% solids epoxy moisture control system designed to address high moisture conditions in new and existing concrete surfaces. It is particularly suited for fast-track construction projects where time efficiency is critical. This article provides a detailed overview of its installation process, technical specifications, and key features based on official documentation and product descriptions from ARDEX Americas and related sources.
Overview of ARDEX MC RAPID
ARDEX MC RAPID is a specialized moisture management system that suppresses excessive moisture vapor emissions in concrete substrates before the installation of flooring systems. It is a solvent-free, alkali-resistant epoxy resin system that adheres tenaciously to the substrate and reduces moisture vapor emissions to acceptable levels for floor coverings. The system is ideal for both residential and commercial applications and is compatible with a wide range of ARDEX flooring products, including underlayments and toppings.
The product is formulated for rapid installation, allowing the application of underlayment or topping as soon as four hours after coating. This makes it particularly suitable for environments where construction schedules are tight, such as healthcare facilities and institutional buildings.
Key Features of ARDEX MC RAPID
ARDEX MC RAPID offers several advantages over traditional moisture control systems. These features are outlined below and reflect the product's performance and application benefits.
- One-Coat Application: The system requires only one application, eliminating the need for multiple coats or sand broadcast for underlayment applications up to 1/4” (6 mm) in thickness.
- Fast-Setting: ARDEX MC RAPID allows for a primer to be applied in as little as four hours, significantly reducing project timelines.
- Moisture Resistance: It is effective for relative humidity (RH) readings up to 100%, making it suitable for both new and existing concrete slabs with high moisture content.
- Solvent-Free and Alkali-Resistant: The system is formulated without solvents, reducing VOC emissions, and is resistant to alkali in concrete, ensuring long-term durability.
- ASTM Compliance: The product complies with ASTM E96 standards, with a permeability rating of 0.06 perms.
- Compatibility: It is compatible with all standard commercial and residential floor coverings and all ARDEX interior toppings when applied using the sand broadcast method.
- Coverage Rates: The coverage varies depending on the thickness applied. At 10 mils (250 microns), the product covers approximately 250–270 sq. ft. (23–25 sq. m) per mixed unit, and at 14 mils (350 microns), it covers approximately 170–190 sq. ft. (16–18 sq. m) per mixed unit.
- VOC Content: The VOC content of the product is 19.9 g/L, meeting low-VOC requirements for environmentally conscious construction projects.
Installation Process for ARDEX MC RAPID
The installation of ARDEX MC RAPID requires careful preparation and adherence to recommended procedures to ensure optimal performance. Below is a step-by-step guide to the installation process, based on the manufacturer's documentation and technical specifications.
1. Surface Preparation
Prior to applying ARDEX MC RAPID, the concrete surface must be properly prepared. This includes cleaning the surface to remove any contaminants such as oil, grease, or previous coatings. The surface should be dry and free of standing water. It is also important to ensure that the concrete is structurally sound and free of cracks or other defects that could affect the performance of the moisture control system.
In some cases, a mechanical profile may be required to enhance adhesion. However, for most applications, mechanical profiling is not necessary. The surface should be free of dust and loose material, and a primer may be applied if recommended by the manufacturer.
2. Mixing the Product
ARDEX MC RAPID is a two-part system consisting of a resin (Part A) and a hardener (Part B). The mixing ratio is fixed, and the user is instructed to add the entire pre-measured contents of Part B into Part A. It is important to mix the components thoroughly to ensure a homogenous mixture.
The working time for the mixed product is approximately 20 minutes, after which the pot life begins. Once mixed, the product should be applied immediately to the substrate. Delaying the application may result in premature setting and reduced performance.
3. Application of ARDEX MC RAPID
After mixing, the product is poured onto the prepared concrete surface. It is designed to self-level and spread evenly, eliminating the need for additional tools or techniques. The thickness of the application depends on the moisture readings of the concrete slab.
- For RH readings up to 85% (ASTM F2170): Apply at 10 mils (250 microns).
- For RH readings over 85% and up to 98% (ASTM F2170): Apply at 14 mils (350 microns).
The application should be continuous and uniform to ensure even coverage and optimal moisture suppression. No sand broadcast is required for underlayment applications up to 1/4” (6 mm) in thickness. However, for thicker applications, a third coat of ARDEX MC PLUS with sand broadcast may be necessary, or the ARDEX MC ULTRA™ system can be used.
4. Curing and Drying Time
After application, the system begins to cure. The time required for the system to cure is relatively short, allowing for quick project turnaround.
- Walkable Time: The surface can be walked on in approximately 4 hours.
- Underlayment or Topping Installation: An underlayment or topping can be installed in a minimum of 4 hours after the application of ARDEX MC RAPID.
This rapid curing time is one of the key advantages of the product, making it suitable for projects where time is a critical factor.
5. Post-Application Considerations
Once the system has been applied and cured, it is important to ensure that the surface is ready for the next phase of the project. This includes verifying that the moisture levels have been reduced to acceptable levels for the intended flooring system.
In some cases, a moisture test may be required to confirm that the ARDEX MC RAPID has effectively suppressed moisture emissions. The manufacturer recommends following ASTM F2170 standards for moisture testing in concrete slabs.
Additionally, it is important to follow the manufacturer's guidelines for the installation of any subsequent flooring systems. ARDEX MC RAPID is compatible with a wide range of flooring materials, including underlayments, toppings, and sealers. However, the specific requirements for each material should be reviewed to ensure proper installation.
Compatibility and Application Guidelines
ARDEX MC RAPID is compatible with a variety of flooring systems and underlayments. It is particularly well-suited for use with ARDEX Americas underlayments and toppings, and it supports the use of sand broadcast methods for underlayment applications.
The product is suitable for both interior and exterior applications, depending on the specific formulation and environmental conditions. However, the manufacturer notes that ARDEX MC RAPID is intended for use on interior substrates only.
For exterior applications, alternative moisture control systems may be required, and the manufacturer recommends consulting with the ARDEX Technical Service Department for guidance.
Technical Specifications and Performance
ARDEX MC RAPID is a high-performance moisture control system that is designed to meet the demands of modern construction projects. Below are some of the key technical specifications and performance metrics associated with the product:
- Moisture Vapor Emission Suppression: The system is effective in reducing moisture vapor emissions to acceptable levels for most floor coverings.
- Permeability: The product has a permeability rating of 0.06 perms, as measured by ASTM E96.
- pH Resistance: It is resistant to 14 pH solutions, as tested by ASTM D1308.
- VOC Content: The product has a VOC content of 19.9 g/L, making it suitable for low-VOC environments.
- Working Time: The working time after mixing is approximately 20 minutes.
- Pot Life: The product should be applied immediately after mixing, as it has a short pot life.
- Coverage Rates: The coverage rates vary depending on the thickness of the application. At 10 mils, the product covers approximately 250–270 sq. ft. (23–25 sq. m) per mixed unit, and at 14 mils, it covers approximately 170–190 sq. ft. (16–18 sq. m) per mixed unit.
- Packaging and Storage: The product is packaged in one 1.65-gallon (6.25-liter) unit. It should be stored in a cool, dry area away from direct sunlight and freezing temperatures. The shelf life of the product is 1 year if unopened.
Warranty and Extended System Warranty
ARDEX MC RAPID comes with a standard limited warranty, which covers defects in materials and workmanship under normal use and conditions. However, for extended warranty coverage, additional requirements must be met.
The manufacturer requires that users complete an ARDEX MC™ Pre-Installation Checklist and submit it for approval. Additionally, training by the ARDEX Technical Service Department is necessary for eligibility for the extended warranty.
Users are encouraged to contact the ARDEX Technical Service Department for more information on warranty requirements and eligibility.
Safety and Handling
As with any construction material, it is important to follow safety guidelines when handling and applying ARDEX MC RAPID. The product is a chemical-based system that should be used in a well-ventilated area to avoid the risk of inhalation or skin contact.
Safety data sheets (SDS) are available for the product and should be reviewed prior to use. These documents provide detailed information on the hazards associated with the product, as well as recommended personal protective equipment (PPE) and emergency procedures.
Users should also ensure that they are trained in the proper application and handling of the product to minimize the risk of accidents or exposure.
Conclusion
ARDEX MC RAPID is a high-performance, one-coat moisture control system that is designed for fast-track installation in both new and existing concrete substrates. It offers a range of advantages, including rapid curing, solvent-free formulation, and compatibility with a wide range of flooring systems. The product is suitable for both residential and commercial applications and is particularly well-suited for environments where time efficiency is a priority.
By following the manufacturer's installation guidelines and technical specifications, users can ensure optimal performance and longevity of the ARDEX MC RAPID system. The product is backed by a standard limited warranty, with extended warranty options available for qualified projects.