Box Culverts
Made-to-order concrete culverts for drainage, access and water management
Why choose precast Box Culverts?
Box culverts offer a durable, low-maintenance alternative to in-situ construction. The smooth mould finish enhances flow efficiency, while the interlocking spigot-and-socket joint guarantees quick alignment and easy sealing.
They are designed to meet your project’s loading, flow, and structural requirements and can be customised with additional features such as mammal ledges, V-channels, flow channels, or twin-box systems.
Made to order – manufactured to your required width, height and loading
Fully customisable – with optional flow channels, mammal ledges, headwalls and more
Fast installation – delivered ready to place on a prepared foundation
Durable and long-life – design life up to 120 years
Watertight – spigot-and-socket joints sealed with mastic or rubber strip
High performance – suitable for heavy loading, deep cover and high surcharge
With our Box Culverts, you’ll get:
Response from the team within 4 working hours
Full technical support with drawings and specification guidance
UK-wide delivery on reliable lead times
Sizes & Product Range
Precast box culverts are available in a wide range of internal spans and heights to suit both drainage and access applications.
- Internal widths: 500mm to 6,000mm
- Internal heights: 500mm to 3,600mm
- Section lengths: typically 1,000–2,000mm, depending on size and weight
All units feature a spigot-and-socket interlocking joint for quick installation and precise alignment.
Joints can be sealed using a rubber strip or mastic where a watertight connection is needed.
Flexible, customisable culvert options
Box culverts can be manufactured with a range of additional features to
- Mammal ledges: cast into the culvert to enable wildlife to pass safely above the water level
- Flow channels: half-round channels cast into the base, available in multiple sizes
- Twin-box configurations: for separating water flow from dry access routes
- V-channels: designed to increase flow rate and reduce silt build-up
- Headwalls & wing walls: supplied to match culvert opening dimensions
- Open culverts with cover slabs: ideal for cable channels or maintenance access routes
Product Features & Specifications
Concrete: C50
High-strength concrete ensures long-term durability and consistent performance, even in demanding environments.
Material density: 18 kN/m³
Engineered for stability, load-bearing performance and resistance to environmental conditions.
Surcharge capacity: up to 20 kN/m²
Durable, high-performance concrete suitable for infrastructure projects.
Design life: Up to 120 years
Manufactured to meet long-term performance standards when specified with correct reinforcement cover.
Connection: spigot-and-socket joints
Each section interlocks for rapid installation and accurate alignment.
Edge detail: Chamfered edges
Provides a clean finish and reduces the chance of chipping during handling.
Reinforcement cover: 30mm minimum
Ensures durability and compliance with relevant British and Eurocode standards.
Finish: Smooth mould finish
Improves water flow performance and reduces maintenance requirements.
All precast box culverts are manufactured to BS EN 14,844 and CE marked.
Handling & Installation
Box culverts are supplied with spherical head lifting clutches, with the number and size determined by the overall weight of each section.
Installation is straightforward:
- Delivered ready to place
- Offloaded and positioned using a crane or excavator
- Laid onto a prepared foundation
- Joints sealed with mastic or a rubber strip if required
- No additional fixings needed
A foundation gradient should be included where liquid flow is required through the channel.
Typical Applications
Suitable for:
Storm and foul sewers
Watercourse diversion
Underpasses, tunnels and subways
Open channels and attenuation tanks
Service tunnels and ducts
Cattle underpasses
Pedestrian and vehicle subways
Sea outfalls and discharge channels
Questions We Get All The Time
Costs vary depending on span, height, loading, reinforcement and optional features. Share your project details and we’ll return a tailored quote.
The five most common types are: pipe culverts, arch culverts, box culverts, open culverts and bridge culverts.
When correctly specified, box culverts can achieve a design life of up to 120 years.
Internal widths range from 500–6,000 mm and internal heights from 500–3,600mm. Section lengths typically range from 1,000 to 2,000mm.
Units are placed onto a prepared foundation using a crane, HIAB or other suitable lifting equipment and joined using mastic or rubber strips to create a watertight seal.