CLEARMASTERS
in drainage
levels first
Regulations
and reinstate
for aftercare
The basics
Why drains need access points
Every drain needs points where it can be inspected, cleared and surveyed. The Building Regulations expect access at the head of a drain, wherever it changes direction or gradient, where drains join, and at regular intervals on long straight runs.
If an existing manhole is damaged rather than missing, see manhole repairs. If you don’t know where your drains run, we can trace them first.
We do this work across Surrey, West Sussex, East Sussex, Kent, Hampshire and London, with tankers and engineers in each area most days.
An inspection chamber is a shallow access point that you work on from the surface. A manhole is big enough for someone to get down into. Which you need depends on the depth and the use.
Getting the position, depth and cover right at the start saves a lot of trouble later. A chamber in the wrong place, or with a cover that can’t take the traffic over it, is one of the most common problems we’re called out to.
Step by step
How a new manhole is installed
Step through a typical installation, or let it play. Tap a step to jump to it.
Chamber types
Plastic, concrete or brick?
We’ll recommend the right chamber for the depth, the ground and the loads on it.
| Plastic | Precast concrete rings | Brick | |
|---|---|---|---|
| Typical use | Shallow domestic runs and inspection chambers | Deeper manholes and commercial sites | Repairs, awkward layouts and matching existing chambers |
| Depth | Shallow to medium | Medium to deep | Any, but slower to build |
| Strengths | Light, quick to fit, preformed channels | Strong, and big enough to get into | Can be built to any shape |
| Cover | Matched cover and frame, up to the rating the chamber allows | Any class, set on a cover slab | Any class |
Cover classes
Which manhole cover do you need?
Manhole covers are rated to BS EN 124 by the load they can take, from A15 for gardens up to D400 for roads and beyond.
A cover that’s too weak for where it sits will crack or break, and a rocking or broken cover is a real hazard. Recessed covers can be filled with block paving or slabs so they blend in.
Pick where the manhole is to see the class it needs.
Where is the manhole?
Permissions
Public sewers, adoption and the road
Since October 2011, most shared drains and lateral drains outside your boundary have belonged to the water company. Building over or close to one, usually within 3 metres, needs the water company’s agreement before you start, and a manhole may need moving or rebuilding as part of it.
On new developments, sewers built to the water company’s adoption standards can be adopted under a Section 104 agreement. A new connection to a public sewer needs the water company’s approval, and any work in a public road needs a licence from the highway authority.
We’ll check the sewer records for your site at the survey, and tell you what’s needed.
Check before you build if
- There’s a manhole where the extension will go
- A shared drain runs across the garden
- You’re connecting to the sewer in the road
- Several houses will share the new drains
- The work is in or next to a public road
Why Clearmasters
Why choose Clearmasters?
We survey, jet and repair manholes every day, so we know what goes wrong with them. We build new ones with watertight joints, properly formed benching and the right cover, so they stay trouble-free.
Ask us a questionWe survey before we dig
Levels, ground conditions, buried services and where the water can go, checked before we quote.
Done to the rules
Designed and built to the Building Regulations, British Standards and the manufacturer’s instructions.
We look after it afterwards
We empty, jet, survey and service what we install, so you have one firm for the life of the system.
CCTV before and after
We can survey the drains before we design, and after we connect, so you know it’s right.
What our customers say
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Questions answered
Manhole installation FAQs
What’s the difference between a manhole and an inspection chamber?
An inspection chamber is a shallow access point that you work on from the surface. A manhole is big enough for a person to go down into. Deeper drains need manholes; shallow domestic runs usually just need inspection chambers.
Do I need permission to install a new manhole?
Work on your own private drains doesn’t usually need planning permission, but new drainage for an extension or new building needs Building Regulations approval. Anything on or near a public sewer needs the water company’s agreement.
What cover class do I need?
It depends on what drives over it: A15 for gardens and paths, B125 for driveways and car parks, C250 for kerbsides, and D400 for roads. Use the picker above for a guide.
Can a manhole be inside my extension?
It’s best avoided. If a chamber has to end up inside, it needs a sealed, double-sealed or bolted-down cover, and if it’s on a public sewer, the water company’s agreement. Often the better answer is to divert the drain and build a new chamber outside.
How long does it take?
A single domestic chamber is usually done in a day or two, depending on the depth, the ground and the reinstatement.
How much does a new manhole cost?
It depends on the depth, the type of chamber, the cover and the surface that has to be put back. We’ll give you a free, no-obligation quote after a survey.
Got a different question? Call 03333 233566 or send us a message.
Related services
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