1. More Than Just a Concrete Border
Walk down any organized street in Gulshan, or drive through the Purbachal Expressway, and look down. Separating the chaotic traffic from the peaceful footpath is a line of concrete blocks. These are Kerb Stones (often spelled Curb Stones).
In the rush of construction, kerb stones are often an afterthought—treated merely as a cosmetic “border line.” This is a mistake. In Bangladesh’s heavy-rain climate and dense traffic conditions, the kerb stone is an engineering necessity. It acts as the structural rim that holds the road together. Without it, the edges of asphalt roads would crumble under the weight of buses, and rainwater would seep under the pavement, destroying the road base.
This guide explores why these heavy concrete blocks are critical for modern infrastructure, how to choose the right type, and the correct way to install them.
2. The Three Critical Roles of a Kerb Stone
Before we discuss prices, we must understand why we are buying them. A kerb stone has three specific jobs:
2.1. The Structural Retainer
Think of a paved road like a spread of butter. When a heavy truck drives on the edge, the asphalt wants to spread outwards. The kerb stone acts like the rim of a plate. It physically locks the pavement layers (sand, brick chips, bitumen) in place, preventing “edge spreading.”
2.2. The Drainage Channel
In Bangladesh, drainage is everything. A properly installed kerb acts as a wall that forces rainwater to flow along the gutter line into the nearest catch pit or drain. Without kerbs, water washes onto the soil, turning road shoulders into mud pits.
2.3. The Safety Barrier
For pedestrians, the kerb is the line of defense. A “Barrier Kerb” (6 inches high) provides a physical and psychological check for drivers. When a rickshaw or car tire hits the kerb, the driver feels it immediately and steers back, saving the person walking on the footpath.
3. Types of Kerb Stones in the Market
Not all kerbs are designed to stop cars. Choosing the wrong profile can lead to accidents or damaged vehicles.
3.1. Barrier Kerb (Upstand Kerb)
- Profile: Vertical and high.
- Function: To strictly prevent vehicles from leaving the road.
- Use Case: City streets, busy footpaths, median dividers, and bridge approaches.
- Standard Size: Typically 6 to 8 inches exposed above road level.
3.2. Mountable Kerb (Roll-over Kerb)
- Profile: Sloped or chamfered face.
- Function: Allows a vehicle to drive over it slowly without damaging the tires.
- Use Case: Driveway entrances, parking lot borders, and suburban roundabouts.
3.3. Garden Edging / Pin Kerb
- Profile: Small, rectangular, often decorative.
- Function: Purely aesthetic or to hold garden soil. Not meant for traffic impact.
- Use Case: Parks, rooftop gardens, and walkway borders.
4. Manufacturing: Wet Cast vs. Hydraulic Press
When ordering, your supplier might ask: “Do you want Wet Cast or Pressed?” Here is the difference.
Table 1: Manufacturing Method Comparison
| Feature | Wet Cast (Vibrated) | Hydraulic Pressed (Semi-Dry) |
| Process | Liquid concrete poured into molds and vibrated. | Dry mix compressed by a high-tonnage machine. |
| Surface Finish | Extremely Smooth (Glass-like). | Textured (Like a sandpaper/block). |
| Strength | High (if cured well), but corners can chip. | Very High (Uniform density). |
| Aesthetics | Premium look. Paints look shiny on it. | Industrial look. Good for heavy roads. |
| Cost | Higher (Slower production). | Lower (Mass production). |
| Durability | Good against rain. | Excellent against abrasion (tire rubbing). |
Recommendation: For high-end residential areas or where you plan to paint the kerbs (Black/Yellow), use Wet Cast. For highways or industrial zones, use Hydraulic Pressed.
5. Technical Specifications & Dimensions
In Bangladesh, there is no single “standard,” but most manufacturers follow the Public Works Department (PWD) or City Corporation norms.
Table 2: Common Kerb Stone Sizes (Inches)
| Type | Length (L) | Height (H) | Width/Thickness (W) | Weight (Approx) |
| Standard Road Kerb | 18″ or 20″ | 12″ | 6″ | 45 – 55 kg |
| Heavy Duty Kerb | 24″ | 15″ | 6″ | 60 – 75 kg |
| Garden Kerb (Small) | 20″ | 8″ | 4″ | 15 – 20 kg |
| Channel Kerb | 18″ | 6″ | 10″ (Flat) | 30 – 40 kg |
Note: The “Channel Kerb” (or water channel) is laid flat in front of the upright kerb to carry water.
6. Market Price Analysis (2026)
Due to the heavy weight of kerb stones, transportation costs are a huge factor. The prices below are ex-factory (factory gate price).
Table 3: Estimated Price List (BDT)
| Product | Size (LxHxW) | Price Range (BDT/pc) | Remarks |
| Road Kerb (Pressed) | 18″ x 12″ x 6″ | ৳ 160 – ৳ 190 | Most common for roads. |
| Road Kerb (Wet Cast) | 18″ x 12″ x 6″ | ৳ 200 – ৳ 240 | Premium smooth finish. |
| Garden Edging | 20″ x 8″ x 3″ | ৳ 65 – ৳ 85 | For landscaping only. |
| Divider Block | Custom Shapes | ৳ 250+ | Heavy median blocks. |
7. The Installation Process: The Hidden Concrete
A kerb stone sitting on dirt is useless. If a truck hits a loose kerb, the stone will pop out. Proper installation requires Haunching.
- Trenching: Dig a trench along the road edge, wider than the kerb stone.
- Concrete Bed: Pour a 3-4 inch layer of lean concrete (mix 1:3:6) at the bottom. This prevents the kerb from sinking.
- Placement: Set the kerb stones on the wet concrete bed. Use a string line to keep them perfectly straight.
- Haunching (Backing): This is the most important step. Pour concrete behind the kerb stone, halfway up its height. This concrete wedge (haunch) locks the stone in place so it cannot be pushed over by traffic.
- Jointing: Fill the vertical gap between stones with a strong mortar (1:3).
- Painting: Apply weather-resistant traffic paint (Thermoplastic or Epoxy) for visibility.
[Image suggestion: Diagram showing the cross-section of a kerb stone with concrete haunching behind it]
8. Why Pre-Cast is Beating Cast-in-Situ
In the past, Bangladeshi contractors would build wooden shutters and pour concrete borders directly on the road (Cast-in-Situ). Today, almost everyone uses Pre-Cast.
Why the switch?
- Quality Control: Factory-made kerbs are vibrated and cured perfectly. Site-made kerbs often have honeycombs and weak spots.
- Speed: You can install 500 feet of pre-cast kerb in a day. Pouring that much on-site would take days of shuttering and curing.
- Repair: If a truck breaks one pre-cast stone, you dig it out and replace it. If a cast-in-situ wall breaks, you have to demolish and re-cast a large section.
9. Common Issues and Solutions
The “Rickshaw Axle” Problem
In Bangladesh, rickshaws often crowd the edge of the road. If the kerb is too high (more than 7 inches), the rickshaw axle or pedal scrapes against it.
- Solution: For mixed-traffic lanes, keep the exposed kerb height at 6 inches (150mm) maximum. This is high enough to stop a car but low enough to avoid most rickshaw pedals.
Water Trapping
Sometimes, the road is re-carpeted (new asphalt layer) without raising the kerb. Eventually, the road becomes higher than the kerb.
- Result: Water flows over the kerb onto the footpath or gets trapped in the middle of the road.
- Solution: When re-carpeting a road, kerb stones must be lifted and re-set to maintain the height difference.
10. Conclusion
Kerb stones are the unsung heroes of urban infrastructure. They define the boundaries of our public spaces, manage our monsoon water, and protect pedestrians from the chaos of the road. Whether you are paving a private factory driveway or working on a municipal contract, investing in high-strength, properly installed kerb stones is an investment in the longevity of your road.
Don’t just buy a block of concrete; buy a system that keeps your road safe and your drainage dry.
Next Step for You:
Different projects require different “Kerb Mix Designs” (e.g., M25 vs M30 concrete). Would you like me to provide a specification sheet that you can copy-paste into your tender documents or purchase orders to ensure suppliers give you the correct strength?
