Koster WS 6000 - Self-Leveling, Cementitious Wear Surface - 50 lb Bag - SL 295 022

Order By Phone 800-515-1002
Free Local Delivery Available (NYC & Greater Area)*
Pick Up Available in Westchester & NYC
Need Product Help? Speak With A Pro 914-920-3232

Self-leveling, cementitious wear surface.


KOSTER WS 6000 is a self-leveling, cementitious topping and resurfacer intended to be used as a wear surface. KOSTER WS 6000 may be polished, stained or sealed with KOSTER K1 Sealer. The product is walkable in 3-4 hours depending on ambient conditions.

Technical Data

 Working Time: Approx. 25-30 min at 70oF (ASTM C1708)
Thickness: 3/8 in to 1 1/4 in neat, up to 5 inches with aggregate
Compressive Strength: >6000 psi at 28 days (ASTM C109)
Initial Set: Approx. 30 min (ASTM C191)
Walkable: Approx. 3-4 hr
Install Flooring: Approx. 16 hr (depending on temp. and humidity)
Polishable Approx. 24 hr (depending on temp. and humidity)


Fields of Application

KOSTER WS 6000 is designed for levelling unevenness of concrete substrates as well as surfaces covered with KOSTER VAP I® 2000 moisture control coatings. It is intended for interior use only.


Substrates to receive KOSTER WS 6000 must be sound, clean, and free of curing compounds, oil, grease, paint, loose particles, or any contaminant that may weaken bond. The tensile pull off strength of the substrate must be at least 200 psi (ASTM C1583). Do not acid etch substrates. Do not clean concrete substrate with chemicals. Do not bridge movement joints with KOSTER WS 6000. Environmental temperature must be 60 - 90°F.


Priming: Before installing KOSTER WS 6000, it is essential to prime the surface using KOSTER VAP I® 2000 moisture mitigation products, KOSTER MPE, or KOSTER ES. Each product requires a sand broadcast to rejection (approximately 0.5 lb/ft² for sand broadcast). Please consult the KOSTER Technical Data Sheets for detailed installation instructions.

Mixing: Mix TWO bags of KOSTER WS 6000 at a time. Measure out exactly 10 quarts (9.5 L) of clean potable water. (5 quarts water (4.7L) for each 50-lb bag.) Pour approximately 8 quarts of the water into the mixing vessel. Add two 50-lb. bags of KOSTER WS 6000 in increments while mixing with an electrical mixer equipped with a suitable helical or egg-beater style mixing paddle at 600 - 700 rpm. Add the final 2 quarts of water to the mix at the end as needed until all 10 quarts are added. Do not over-water! After all material and water has been added into the mixing vessel, mix for a total of 2 to 3 minutes. The resulting consistency must be smooth, flowable, and lump free.

Installation: Pour mixed KOSTER WS 6000 onto the floor and spread using a gauge rake at minimum thickness of 3/8" and a maximum thickness of 1 1/2". For projects where rubber-wheels with a high load are to be used, the minimum thickness should be 1/2". If polishing the KOSTER WS 6000, the minimum thickness should be 1/2". A smoothing tool should be used to blend freshly poured material into adjacent pours. Wear non-metallic cleated shoes, NOT metal spikes. A spike roller should be used immediately after raking or smoothing to help remove any trapped air (within a 10 minute timeframe). Protect poured underlayment from excessive heat, cold, premature drying, or freezing. Setting and drying times will be shortened in hot temperatures and extended in cold temperatures.

Polishing: KOSTER WS 6000 may be polished after being allowed to properly cure for 24 hours. Use standard industry techniques when polishing. A test area is always recommended prior to installation of the full area to determine suitable results. Product may be top-coated with KOSTER K1 Sealer. (Refer to product Technical Data Sheet.)

Coverage (Dependent on application)

3/8" 18 ft2/bag
1/2" 12 ft2/bag
3/4" 8 ft2/bag
1" 6.25 ft2/bag


Clean mixing equipment thoroughly with water and stiff scrub brush to avoid getting hardened product into subsequent batches. Keep mixing bucket clean.

Eligible LEED Credits
Recycled Content
Regional Materials
Low Emitting Materials

50 lb bag (SL 295 022)

Store in a cool, dry place. When stored properly in original, unopened bags, shelf life is 12 months.

The information contained in this technical data sheet is based on the results of our research and on our practical experience in the field. All given test data are average values which have been obtained under defined conditions. The installer is responsible for the correct application taking into consideration the specific conditions of the construction site and the final results of the construction process. This may require adjustments to the recommendations given here for standard cases. Specifications made by our employees or representatives which deviate from the specifications contained in any Company literature may not be relied upon in the absence of written confirmation from the Company. The installer must comply with all testing, technical requirement, guidelines, and industry customs at all times. The terms, conditions, and limitations contained in the written warranty for the product controls over the specifications contained herein. This guideline has been technically revised; all previous versions are invalid.