SikaWall®-421 Alto

15 months, properly stored in original containers

Store off ground and protect from moisture and direct sun, do not allow to freeze.

<20 grams per liter

• Avoid heavy rain, traffic or cleaning for 48 hours after application.
• 3-4 hours under normal conditions.
• High humidity and low temperatures extend drying time.

Coverage will vary depending on surface conditions and thickness of application.

• 175-200 ft² (16-18.6 m²) per 5 gallon pail (two coats).

Clean tools frequently using clean water prior to drying.

• Substrate must be clean, dry, sound and free of contaminants such as dust, oil, mildew and efflorescence.
• Ambient conditions, substrate and the product itself must be at a minimum of 40°F during application and at least 48 hours following until the finish is fully dried. 
• Cement and gypsum plaster basecoats should cure for at least 7 days before applying the finish .

Concrete Masonry/ Concrete/Stucco

• Stucco surfaces should be fully cured ( minimum 7 days)  before application.
• Concrete Masonry  and Poured in place concrete surfaces should cure for at least 28 days before finishing.
• Remove all form release agents and efflorescence and grind down form lines or other irregularities which protrude from the plane of the substrate.
• Pre-fill any depressions in the plane of the substrate such as holes and cracks using SikaWall ArmourPlast or an approved patching/joint compound.

New Drywall ( interior)

• Treat all joints, fasteners and accessories with the industry standard joint treatment system for attaining a Level 3 finish as outlined in the Gypsum Association publication GA-214, “Recommended Levels of Gypsum Board Finish”.
• Substrate must be clean. Remove all foreign matter, alkali deposits, oil, dirt, etc. 
• Painted surfaces must be primed with Sikawall Tinted Primer. 

• Thoroughly mix with a paddle mixer to a homogeneous consistency at low rpm.
• Up to 8 ounces of clean, potable water may be added to adjust viscosity. Close container when not in use.

• Sika Facades recommends that the project owner or designer approve a job site mock-up of the application of this product. The mock-up should demonstrate the product’s appearance under the conditions given by the project specification(s).
• Periodically, as the work progresses, evaluate it from a distance to ensure the desired effect is being produced across the entire surface.
• If installing in a wet environment, the Sika Facades High Humidity Wet Areas specification must be followed.
• Apply SikaWall®-421 Alto with a standard stainless steel plaster trowel. Apply the first coat of SikaWall®-421 Alto using decorative, multi-directional trowel strokes. Achieve the bulk of the filling/leveling the substrate will require with the first coat. Allow the first coat to dry completely before proceeding.
• Inspect the first coat and scrape or sand down high trowel marks and lap lines before proceeding.
• Apply the second coat of SikaWall®-421 Alto using decorative, multi-directional trowel strokes at a thickness of the largest aggregate that is in the material. The second coat of SikaWall®-421 Alto may be applied in a full coverage coat to create a smooth plaster finish. Alternatively the second coat may be textured, leaving some of the first coat exposed in areas creating a distressed old world appearance.
• Allow the second coat to dry slightly and then water-trowel. This is achieved by applying a film of water from a spray bottle set to a fine mist to the surface and then troweling smooth.
• After the second coat has dried to the touch it can be slightly polished using a clean, dry stainless steel trowel.