What Is a Surface Retarder?
A surface retarder is a specialized chemical applied to fresh concrete surfaces to delay the setting of the surface cement paste while the underlying concrete continues to cure. This creates a window of time during which the surface cement can be washed away — revealing the natural aggregate beneath.
Unlike traditional surface retarders that require film covering and tight timing windows, BES surface retarders offer:
- Precision depth control — choose from 0.5mm, 1.0mm, 2.0mm, or 3.0mm
- No film covering required — saving labor, time, and material costs
- Long open time — 12–24 hours of workable window
- High fault tolerance — even with increased spray volume, cleaning depth remains consistent
Four Depths, Four Solutions
BES surface retarders are classified by the depth of cement paste they allow you to remove. Each model is color-coded for easy identification on site, ensuring consistent, repeatable results every time.
| Model | Depth | Applicable Products |
|---|---|---|
| Surface Retarder 0.5 | 0.5 mm | Washed sand floor (No.5 sand), exposed aggregate special |
| Surface Retarder 1.0 | 1.0 mm | Washed sand floor (glass sand), gravel floor (aggregate 1–3) |
| Surface Retarder 2.0 | 2.0 mm | Gravel flooring (aggregate 3–5) |
| Surface Retarder Washed Stone 3.0 | 3.0 mm | Washed stone walls and floors |
This tiered system allows contractors to match the retarder depth precisely to the aggregate size and project requirements — from fine sand finishes to coarse gravel exposed surfaces.
Product Specifications
BES surface retarders are manufactured to the highest quality standards:
| Property | Specification |
|---|---|
| Physical state | Liquid |
| Color | Light blue / light red (model-dependent) |
| VOC content | 0 |
| pH | Acidic |
| Freezing point | 32°F (0°C) |
| Shelf life | 12 months |
| Storage | Sealed, cool, and dry place |
Application Guide
Step 1: Preparation
Use a standard sprayer. Stir the retarder thoroughly before use. The standard application rate is 0.2–0.25 kg/m², depending on the sprayer type, concrete texture, and surface finish.
Step 2: Concrete Inspection
After the concrete surface has been finished and leveled, spray before final setting. The indicator: touch the surface with your hand — if it no longer sticks to your fingers, it's ready for application.
Step 3: Spraying
Pour the retarder into the sprayer or container. Keep the nozzle 30–60 cm from the working surface. Spray evenly from left to right until the retarder color completely covers the original concrete color.
Step 4: Cleaning the Slurry
After the retarder has taken effect — approximately 10–18 hours in summer, 12–20 hours in winter — scrub the concrete surface with a soft brush. Progress through soft brush → hard brush → floor scrubbing machine, while using running water and a high-pressure washer to rinse the slurry away from the work area.
Why Choose BES Industrial?
With over 16 years of industry experience, BES Industrial is a recognized leader in decorative concrete systems. Our surface retarders are engineered for:
- Consistent depth control — no more guesswork
- Efficient application — no film covering, reduced labor costs
- Flexible timing — 12–24 hour workable window
- Forgiving application — even if you spray a little extra, the result remains consistent
Whether you're a contractor looking for reliable results or a specifier seeking precision, BES has the solution.
Application Showcase
BES surface retarders have been successfully applied to projects across China and beyond, including:
- Washed stone flooring and wall systems
- Gravel polymer pavements
- Exposed aggregate walkways
- Decorative sand-washed surfaces
Our products deliver the natural, textured aesthetic that architects and designers demand — with the engineering reliability that contractors trust.
Contact BES Industrial
Ready to achieve precise, repeatable exposed aggregate results?
Shanghai BES Industrial Development Co., Ltd.
Room 108G, 1/F, Building 10, Pujiang Zhigu, Pujiang Town
Minhang District, Shanghai, China
T: 021-51692846 / 021-34781556
E: https://www.chinabes.com.cn/