Underground drainage is essential for preventing flooding, protecting property foundations and maintaining a hygienic environment. Pipes and fittings made from durable materials facilitate seamless drainage for both domestic and commercial properties.
Table of Contents
- Underground Drainage Fittings Explained
- Types of Fittings
- Standards & Regulations
- How to Choose Drainage Fittings
- Best Practices for Fittings Installation
Underground Drainage Fittings Explained
So, what are underground drainage fittings? Simply put, underground drainage fittings consist of a range of components designed to connect, redirect and manage foul and surface water below ground level. Underground fittings are used to create reliable drainage and ensure wastewater flows efficiently away from a property. Common fittings include adaptors, connectors, couplings and puddle flanges. When correctly specified and installed, these fittings help prevent blockages, leaks and long-term drainage failures.
Use Cases
Underground drainage fittings are used across a wide range of pipe system layouts. They manage foul water drainage, surface water and groundwater collection. Typical applications include connecting horizontal pipe runs, changing direction around foundations and joining branch pipes into a main drain. They also link pipes to inspection chambers, which are crucial for maintaining systems. Along with helping to maintain hygiene standards, they help buildings remain compliant with drainage and waste disposal statutory guidance.
Materials
Fittings are commonly manufactured from durable plastics designed for below ground use. This includes uPVC, polypropylene and polyethylene. Some fittings may also incorporate rubber seals or EPDM components to create watertight connections. The chosen material should always be compatible with the pipework and suitable for the surrounding ground conditions.
Pipe Sizes
The most common size for domestic drainage is 110mm, typically used for soil pipes and general foul water systems. Larger diameters, such as 160mm, are often specified for higher flow rates, shared drainage runs or small commercial applications. These sizes cover everything from domestic drainage needs to smaller commercial systems. Selecting the correct size is essential to maintain adequate flow capacity and reduce the risk of blockages. If you need guidance, we recommend consulting our helpful team to ensure your pipe sizes are accurate.
Types of Fittings
There are several types of fitting, each designed for a specific purpose within a pipe system. Let’s review the following fittings and explain their role within your underground drainage system.
Adaptors
Adaptors help connect two different-sized drainage pipes and fittings within an underground drainage system. Adaptors often incorporate neoprene or EPDM rubber bodies. These materials help accommodate minor movement, vibration and thermal expansion, which is a necessity in colder climates. Along with providing a secure and watertight connection, adaptors help prevent leaks and structural weakness at junction points.
Connectors
As per their name, connectors are designed to join two sections of pipe or fittings together. They help maintain alignment and ensure a continuous sealed drainage path. Connectors are important for reducing the likelihood of joint failure and maintaining underground drainage systems over a long period of time.
Couplings
Pipe couplings are available in a wide range of sizes, typically from 32mm to 400mm in diameter. They are commonly specified for maintenance work, pipe replacements or situations where slight misalignment needs to be accommodated. Couplings provide a strong mechanical joint while allowing a controlled degree of movement.
Puddle Flange
Puddle flanges help maintain a watertight seal. They’re used where a pipe passes through a concrete structure or the walls of a building. It's designed to prevent water ingress or leakage. They form a physical barrier within the concrete to maintain watertight integrity.
Standards and Regulations of Underground Drainage Fittings
Underground drainage fittings must comply with relevant British and European standards. This includes BS EN 1401 for plastic drainage pipes and ensures safety, performance and durability. In commercial settings, additional compliance is required to meet local authority and environmental requirements. Using certified fittings ensures underground drainage performs as intended.
How to Choose the Right Drainage Fittings for Your Project
The right drainage fittings are essential to prevent flood damage, maintain hygienic standards and keep systems operating efficiently. Consider the following when choosing the right drainage fittings:
- Pipe diameter and flow requirements
- Compatibility with existing materials and connection types
- Conditions of the installation environment
- Compliance with relevant standards
- Future access requirements for maintenance and inspections
It’s important to assess all these factors early in the design stage to avoid costly structural changes later in the project.
Domestic vs Commercial Applications
Commercial applications will often require higher load ratings, since they are typically subjected to greater traffic loads, deeper installations and higher volumes of wastewater. Domestic drainage systems typically involve smaller pipe sizes with fittings designed for lower flow volumes. Consider the demands of the property before choosing underground drainage fittings and connectors. Assess your needs or consult a professional, such as the experts at Drainfast, before deciding on drainage fittings.
Ground Conditions and Load Requirements
Ground conditions should also be considered when choosing the right drainage fittings. Heavy traffic areas and deep installations may require fittings with higher load bearing capabilities. Along with durable inspection chambers to check for blockages, soil type, water table level and potential ground movement should all be considered. Flexibility becomes especially important in more unstable soils.
New or Existing Systems
New drainage systems allow for greater flexibility in fittings and layout design. Existing systems often require adaptors or specialist couplings to integrate new components. When retrofitting, assess the condition and material of existing pipes to ensure compatibility. Careful selection helps maintain system performance without compromising older sections of the network. Updating existing systems might require consulting experts to ensure you select the right fittings.
Best Practices for Underground Drainage Fittings Installations
Correct installation all starts with proper planning. Create detailed plans and consult with specialists to ensure you have the right fittings.
- Ensure all underground drainage pipes and fittings are the correct size
- Maintain the correct gradient to promote consistent flow
- Use appropriate bedding material to support pipes evenly
- Check seals and joints are clean to prevent leaks
- Test connections as a proactive measure to identify any issues
Pre-project Support
Work with a specialist provider of drainage supplies, such as the experts at Drainfast. Our team of experienced suppliers can assist with product selection, compliance guidance and design considerations. We also offer a free material take off service to help keep you on budget, reduce material waste and prevent project delays.
Find the Right Drainage Fittings With Drainfast
Whether you are working on a small domestic project or a large commercial installation, Drainfast offers a comprehensive range of underground drainage fittings to suit your needs. Reach out to our team of experts for advice, insight and expert support. We’re here to make sure you find the right components for your project. Fill out our contact form, give us a call on 01420 555600 or send us an email at [email protected].
