Description
Dust reduced, cementitious, self-leveling underlayment
PRODUCT DESCRIPTION
Sika® Level-425 is a one-component, durable and
versatile cementitious underlayment for interior
concrete and cementitious substrates. It can be applied
manually or by pump to produce a self-smoothing,
rapid-setting, and flat substrate prior to the application
of a final floor finish. Typical application thickness is
1/16” to 2” (1.5 to 50.8 mm).
USES
▪ Concrete
▪ Cement substrates
▪ Rapid drying cement screed systems
▪ OSB/Plywood only suitable for flexible coverings
▪ Ceramic tiles, terrazzo or natural stones
CHARACTERISTICS / ADVANTAGES
▪ Highly fluid self-leveling
▪ Levels new and renovates old floors
▪ Interior only
▪ Manual or pumpable applications
Excellent underlay for all type of residential and
commercial flooring
▪
▪ Compatible with subfloor heating systems
▪ Superior workability for easy installations
▪ Dust reduced
▪ Extended working time
▪ High strength
▪ Very low shrinkage
▪ Smooth finish ready for floor covering
Can accept caster wheel loading if the thickness is
greater than 1/8’’ (3.2 mm)
▪
PRODUCT INFORMATION
Chemical Base Cement-based, polymer-modified binder system and fillers
Packaging 55 lb (24.9 kg) bag
Appearance / Color Gray powder
Shelf Life 12 months from date of production if stored properly in original, unopened
and undamaged sealed packaging
Storage Conditions Store dry at 41–86 °F (5–30 °C)
Protect from moisture. If damp, discard material
TECHNICAL INFORMATION
Compressive Strength 1 day 2,000 psi (17 MPa)
7 days 4,200 psi (29 MPa)
28 days 5,600 psi (39 MPa)
(ASTM C-109)
73 °F (23 °C)
50 % R.H.
Flexural Strength 28 days 1,000 psi (7 MPa) (ASTM C-293)
73 °F (23 °C)
50 % R.H.
APPLICATION INFORMATION
Mixing Ratio 6.5-7 qts (6.2- 6.6 L)
Fresh mortar density 118 lb/ft3 (1.9 kg/l) (ASTM C-138)
Coverage 30 ft2 at 1/4” (2.78 m2 at 6 mm) per bag
(Coverage figures do not include allowance for surface profile and porosity or material waste)
Layer Thickness Min. Max.
Neat 1/16”
(1.5 mm)
1” (25.4 mm)(1.25″ in areas <100 sqft.)
Extended 1/4”
(6.3 mm)
▪ up to 1.5” (38 mm) (35 lb. of sand per 55 lb. bag) (2″ in areas <50 sqft.)
▪ up to 2” (50.8 mm) (55 lb. of sand per 55 lb. bag) (2.5″ in areas <50 sqft.)
Product Temperature 65–75 °F (18–24 °C)
Ambient Air Temperature 41–86 °F (5–30 °C)
Note: When using water based adhesives on the finished product the best results will be achieved at ambient
and substrate temperatures between 59 and 77 °F (15–25 °C).
Relative Air Humidity < 75 %
Note: The substrate and uncured product applied on the floor, must be at least 5 °F above dew point to reduce
the risk of condensation, blooming or cement laitance forming on the surface.
Substrate Temperature 41–86 °F (5–30 °C)
Pot Life ~ 30 minutes
As the temperature will affect the pot life, application temperature:
▪ Above 73 °F (23 °C) will reduce the pot life and the working time.
▪ Below 73 °F (23 °C) will extend the pot life and the working time.
Waiting / Recoat Times ~ 30 minutes
Applied Product Ready for Use Walk-on time: 3 hours
Suitable for overcoating with:
Non moisture sensitive floor covering 3 hours
Moisture sensitive floor covering 16 hours up to 3/8″ (9.5 mm)*
