TOP-STOP – Concrete Surface Retarder

TOP-STOP is a spray-applied, water-soluble surface retarder designed to slow the set of surface mortar in concrete to expose the aggregate. It temporarily halts the set of Portland cement at the surface while the concrete below the surface cures normally. TOP-STOP is economical and easy to use, producing beautiful exposed aggregate concrete flatwork with consistent results. TOP-STOP is non-flammable and VOC-compliant.

TOP-STOP may be used to produce an architectural finish on concrete slabs by exposing the natural color and texture of the aggregate. TOP-STOP exposes the aggregate on floor slabs, sidewalks, tilt-up and precast panels, or any normal horizontal concrete application. TOP-STOP produces roughened bonding surfaces for subsequent concrete toppings and roughens horizontal surfaces for construction joints in power plants, dams, and other civil engineering projects.


  • Architectural-quality appearance with original color and texture of the aggregate without sandblasting.
  • Easy, economical removal of the concrete surface without laborious chipping or blasting required.
  • No danger of acid residue from strong washing compounds.
  • Easy to use.
  • Less supervision of field personnel.
  • No expensive equipment required.
  • Uniform coverage results in uniform aggregate exposure; consistent results.
  • Easy water cleanup.
  • VOC compliant … actual VOC content is 0.

1 Gallon (3.79 L) Units
5 Gallon (18.93 L) Pails

Two years in original, unopened container

Color: Green
Solids, %: 18
Weight/gallon, lb./gal.: 8.94
Coverage, ft.²/gal.: 150-300

Approximately one gallon per 150-300 ft.² to retard the exposed aggregate to a depth of 1/8″ (0.32 cm) to 3/16″ (0.48 cm).
**Coverage may vary due to porosity and condition of the concrete.


Store in dry conditions, between 40° F and 95° F (4° C and 35° C). Keep from freezing.

Apply TOP-STOP with a low-pressure sprayer immediately after screeding when concrete has lost its sheen, or as soon as bleed water has disappeared. Apply only after all finishing operations are complete. Avoid puddles and over spraying.

Cover concrete with wet burlap or plastic sheeting to prevent drying out. Secure the edges of the plastic sheeting to prevent ballooning. Do not use curing compounds. Concrete admixtures which affect the setting time should not be used without first conducting a test patch. Periodically check concrete to determine depth of retarded mortar, making sure concrete hardens.

Within 12-24 hours of application (depending on temperature and humidity), remove burlap or plastic sheeting one section at a time and wash the retarded surface mortar using a low-pressure garden hose and stiff broom. Do not use excessive force. Test a small area to determine if depth of retarded mortar is at desired level. If the depth is greater than desired, allow the slab to cure longer before exposing the aggregate.

Stone color can be enhanced using EXPO-GLOSS® exposed aggregate surface sealer from W. R. MEADOWS.

Cleanup … TOP-STOP may be easily removed by water and scrubbing with a wire brush.

Apply only on freshly poured concrete. Depth of the exposed aggregate will be affected by extreme temperatures, as well as the water pressure and scrubbing action used during removal. A test patch under exact job conditions is recommended. Do not use on vertical concrete or form applications. Do not use on concrete containing calcium chloride or other set accelerators. Do not apply to frozen surfaces. Protect treated area from freezing. Do not store in metal sprayers for long periods of time.

Direct contact may result in mild irritation. Refer to Safety Data Sheet for complete health and safety information.