U-STUCCO™ RDX is a high-quality blend of white portland cement and mineral based lightweight aggregates that conforms to ASTM C926 which is developed as a replacement to job-site mixed scratch & brown base coat stucco. U-STUCCO™ RDX meets code criteria for exterior portland cement plaster.


Cement : ASTM C150
Light Weight Aggregate : ASTM C330 / C332


  • Gain up to 2.2 R value per inch without the addition of any rigid foam board.

  • Covers “thermal breaks” in wall assemblies and significantly enhance any structure’s insulation performance and energy efficiency.

  • Provides superior fire-resistance, water-resistance, moisture protection and thermal insulation compared to conventional stucco.

  • Apply in a single pass of up to 1 inch to nearly any substrate, including plywood, OSB, CMU & AAC blocks, concrete, metal, EPS, XPS, ICF and even on plastic* surfaces.


Meet U-STUCCO™, industry’s lightest ‘true’ one-coat stucco that is revolutionizing the stucco industry with its thermal, fire, water and acoustic insulation properties. It’s an ultra light-weight (1/7th weight of the conventional stucco) hydrophobic, high crack and corrosion resistant, UV reflective, ready-to-use powder-mix product. It provides fire resistance (2hr rated @1200°C/ 2192°F) as well as thermal (up to R 2.2 per inch), water and acoustic insulation (38 dB).

U-STUCCO’s simple one-coat application process greatly reduces time and labor expenses and renders traditional 3-coat application obsolete. U-STUCCO™ can be applied in a single pass of up to 1 inch to nearly any substrate, including plywood, OSB, gypsum, masonry, AAC, steel, foam and plastic substrates.

U-STUCCO™ is ideal for achieving superior energy efficiency. It can be used in conjunction with EPS, XPS, ICF or Fiberglass (Mineral Wool) to create wall assemblies with higher insulation R values and improved crack and water-resistance complying with California Title 24 code helping you build sustainable and energy efficient living spaces. U-STUCCO™ RDX may also be used over wood or gypsum backing and as a scratch and brown coat application for traditional stucco systems.

U-STUCCO™ is 99% inorganic and contains 40% post-consumer recycled content making it a true green product. It is a Class 1 (A1) non-combustible material therefore it doesn’t burst into flame or emit any toxic gas when exposed to fire. It also allows your building to breathe and prevents mold and mildew.


U-STUCCO™ RDX can be used both in new construction and renovation projects. It can be applied on various substrates such as OSB, plywood, concrete, cinder blocks, bricks, densglass, drywall, sheetrock, EPS, XPS, ICF, AAC, wood and steel structures.


Apply by hand trowel or plaster gun.


Ambient and surface temperature must be between +40°F (+5°C) and +95°F (+35°C). Try avoiding application under extreme wind, cold or direct sunlight conditions or when temperatures may fall outside this range within 24 hours of application. Provide supplemental heat and protection from precipitation as needed.


The application surface must be structurally sound, clean, free of dust, mold, dirt, silicones and paint products which may affect the ability of U-STUCCO™ RDX to bond to the surface. Major cracks, holes or voids should be repaired prior to application. The surface shall be wet especially at highly porous and absorbing surfaces or at high temperatures. On lathed construction, apply to lathing installed in accordance with ASTM C1063. U-STUCCO™ RDX requires water-resistive barrier installed and flashed in accordance with the building code and to form a water-shedding surface. Install Water Resistive barrier (type and method of application) per manufacturer’s Guide or Specifications. Do not apply to substrates which are frozen or contain frost or ice.

For application to very dense or smooth concrete and additional surface preparation options, contact U-STUCCO™ USA Technical Support.


Pour U-STUCCO™ RDX 44 lb (20 kg) bag into a mixing container, followed by 3.7 to 4.0 gallons (14 to 15 lt) of cool, clean potable water (let hose run to clear it of hot water) and mix for approximately 12 minutes. For the mixing process, a hand mixer or plastering machine can be used. Mixing should be done mechanically at a high speed until the mixture reaches a homogenous consistency and workability.

Mix same size batches using the same amount of water, to ensure consistency. Briefly re-mix before using (approximately 1 minute). Only U-STUCCO™ USA approved additives can be added to this product.


Thoroughly dampen concrete and masonry substrate if necessary before applying U-STUCCO™ RDX. Apply by hand trowel or plaster gun to a minimum thickness of approximately 1/4 inch (5 mm) On lathed construction the total thickness can be up to 1 inch(25 mm) Using a trowel or plaster pump, apply U-STUCCO™ RDX to the properly prepared surface. Always float the material uniformly to provide a surface receptive to the application of the finish coat. Sand or smooth finish can be easily achieved after 1 to 3 hours after the application depending on the ambient temperature and application thickness. Various finishes can be achieved with different techniques. Always allow U-STUCCO™ RDX to dry thoroughly before applying acrylic primers or finishes.

Read the entire label before using this product. All materials are to be installed in compliance with local building code requirements, ASTM C926, C1063 and U-STUCCO™ USA’s specifications.


The minimum thickness over any substrate is inch (5 mm). Some assemblies may require specific minimum thickness. U-STUCCO™ RDX can be applied up to 1 inch (25 mm) thickness with a single pass.


Curing time may vary due to ambient temperature, surface temperature, surface porosity, application methods, and thickness of material. All freshly applied material must be protected by an approved protective system from inclement weather until fully dry.


Sets in 90 to 120 minutes after mixing, depending on temperature, humidity and substrate conditions.


Approximate Coverage, depending on the condition of substrate and the thickness of application is based on uniform thickness and zero waste factor. 44 lb (20 kg) bag of U-STUCCO™ RDX will cover approximately;



Available in 44 lb (20 kg) net weight in a multi-layer moisture resistant bag. Store off ground and protect from rain and moisture. Storage space temperature should be no lower than +40°F (+5°C)


It may be irritant to eyes and skin when exposed. Wear appropriate dust, skin and eye protection. In case of eye contact, flush immediately with water and consult a physician. Wash hands with soap and water after use. Keep out of reach of children. For more information on handling this product refer to its material safety data sheet (SDS).


U-STUCCO™ Green Building Materials are produced under ISO 9001:2008 quality standards. The product quality is monitored according to the EN 998-1 by U-STUCCO™ USA, LLC in the factory laboratories.


U-STUCCO™ RDX is warranted to perform in accordance with the product specification when used pursuant to the application instructions. This warranty is limited to and shall not exceed the total amount paid by the buyer for the product here under. In no event U-STUCCO™ USA, LLC shall be liable for any loss of profits, special or consequential damages in respect to any claim. The foregoing warranties are in lieu of all other warranties express or implied including those concerning suitability for a particular use.

This product data sheet has been prepared in good faith on the basis of information available at the time of publication. It is intended to provide users with information about the guidelines for the proper use and application of the covered product(s) under normal environmental and working conditions. Because each project is different, U-STUCCO™ USA, LLC cannot be responsible for the consequences of variations in such conditions, or for unforeseen conditions.


This information is designed to guide you and has been conscientiously compiled according to the latest state of our technology. U-STUCCO™ USA assumes no liability, expressed or implied, in connection with the use of the product because of the great variety of applications and working conditions.

Ideal for Title 24 Compliant High Performance Wall Assemblies