A CCTV drain survey is an inspection of underground drainage pipes using a specialist camera. The camera is passed through the drainage system so the condition of the pipework can be viewed from inside without immediately excavating the ground.
This type of survey can help identify the cause of recurring blockages, slow drainage, unpleasant smells, leaks and unexplained ground movement. It is also useful before building work, property purchases or major drainage repairs.
Underground drains are normally hidden beneath floors, gardens, driveways and roads. Without a camera inspection, it can be difficult to know whether a problem is caused by a simple build-up of debris or a more serious structural defect.
A CCTV drain survey provides evidence of what is happening inside the pipe. This allows the contractor or property owner to make a more informed decision about cleaning, repair or replacement work.
How does a CCTV drain survey work?
A CCTV drain survey uses a waterproof camera designed to travel through drainage pipes.
The camera is connected to equipment that allows the operator to view the footage as the inspection takes place. Depending on the pipe size and layout, the system may use a small push-rod camera or a larger remotely controlled unit.
The inspection usually begins at an accessible point such as:
- An inspection chamber
- A manhole
- A rodding point
- An external gully
- An accessible pipe connection
The camera is fed into the drain and moved along the pipe. The operator watches the screen and records visible defects, obstructions and changes in pipe condition.
The distance travelled can normally be measured, helping the operator estimate where a fault is located in relation to the access point.
What happens before the camera is inserted?
Before the survey begins, the drainage contractor may check the accessible chambers and ask about the symptoms.
Useful information can include:
- Which appliances are draining slowly
- Whether the blockage keeps returning
- Where smells are strongest
- When the problem first appeared
- Whether recent building work has taken place
- Whether the issue becomes worse during rainfall
- Whether parts of the garden or driveway have sunk
The drain may need to be cleaned before the camera inspection. Heavy grease, mud, scale or standing waste can obstruct the view and prevent the camera from travelling through the pipe.
High-pressure drain jetting may therefore be recommended before or during the survey.
What can a CCTV drain survey identify?
A camera survey can reveal a wide range of drainage problems that cannot be diagnosed reliably from the surface.
These may include:
- Cracked pipes
- Collapsed sections
- Displaced joints
- Tree root intrusion
- Grease and waste deposits
- Scale build-up
- Foreign objects
- Standing water
- Deformed pipes
- Poor gradients
- Open joints
- Incorrect connections
- Construction debris
- Signs of infiltration or leakage
Some faults are immediately obvious on the recording. Others require interpretation by an experienced drainage professional.
For example, standing water could indicate a local dip in the pipe, a downstream obstruction or an incorrect fall. The position of the water and the surrounding pipe condition help determine the likely cause.
Can the survey show a collapsed drain?
Yes. A camera may show a heavily deformed pipe, a section that has broken away or a complete obstruction where the pipe has collapsed.
In some cases, the camera cannot pass beyond the damaged area. Even then, the footage and distance measurement can help locate the suspected collapse.
Further investigation may be needed from another access point to understand the full extent of the damage.
A collapsed drain usually requires repair or replacement. Simply clearing the pipe will not restore its structural condition.
Can it find tree roots?
Tree roots often enter drains through cracks, damaged joints or other openings.
Once inside the pipe, they can spread through the available space, catch waste and restrict the flow of water. The camera can show where roots have entered and how much of the pipe is affected.
Root cutting may restore flow temporarily, but the opening that allowed the roots to enter may still need repair. Without addressing the structural defect, the roots can return.
Can it identify poor pipe gradients?
A CCTV survey can reveal sections where water is sitting inside the pipe.
Some standing water may indicate that part of the drain has settled or was installed with an inadequate fall. This is sometimes referred to as a belly or dip in the pipe.
A significant low point can collect waste and contribute to recurring blockages.
The camera footage alone may not provide every level measurement needed for a complete redesign, but it can confirm that the drainage is not flowing consistently.
When should a CCTV drain survey be arranged?
A survey is particularly useful when the cause of a drainage problem is unclear or when the same problem keeps returning.
Common reasons for arranging one include:
- Recurring drain blockages
- Several slow-draining appliances
- Persistent sewage smells
- Water backing up
- Suspected pipe damage
- Sunken paving or ground
- Leakage near a drain run
- Drainage problems after construction work
- Planning an extension
- Purchasing an older property
- Checking a drainage repair
- Investigating an off-mains system
A one-off blockage caused by hair, grease or another local obstruction may not always require a full survey.
However, if the drain blocks again shortly after cleaning, there may be an underlying defect that is repeatedly catching waste.
Should a survey be carried out before an extension?
A CCTV drain survey can be very useful before building an extension, particularly where drains run through or close to the proposed footprint.
The survey can help confirm:
- The location of the drainage run
- Pipe condition
- Approximate depth
- The direction of flow
- Existing connections
- Whether rerouting may be needed
- Whether repairs should be completed first
Building over a drain without understanding its condition can create future difficulties. A damaged pipe may become harder to access once it is beneath the completed extension.
A survey can also help identify whether drainage work should be included within the wider groundworks programme.
Is a drain survey useful when buying a property?
A general property survey may not include a detailed inspection of underground drainage.
A specialist CCTV survey can provide additional information, particularly for older properties, rural homes and buildings with a history of drainage problems.
It may identify defects that could otherwise remain hidden until after the purchase, such as:
- Root-damaged pipes
- Repeatedly repaired sections
- Collapsed drains
- Inappropriate connections
- Displaced joints
- Heavy scale
- Poorly maintained off-mains drainage
The findings do not necessarily mean that the purchase should not proceed. They provide useful information for budgeting, negotiation and future maintenance planning.
What happens during the survey?
The exact process depends on the drainage system and the reason for the inspection, but a typical survey follows several stages.
1. The symptoms are reviewed
The contractor asks where the problem occurs and how frequently it happens.
This helps identify which section of the system should be inspected first.
2. Access points are opened
Accessible inspection chambers and manholes are located and opened.
The contractor checks the direction of flow, the number of connecting pipes and whether wastewater is moving through the chamber.
3. The pipe may be cleaned
If the drain is heavily obstructed, it may be cleaned using suitable equipment.
A cleaner pipe gives the camera a clearer view of cracks, joints and other defects.
4. The camera is inserted
The camera is passed through the pipe while the operator monitors the footage.
The direction, distance and visible defects are recorded.
5. Problems are documented
The operator notes where defects appear and assesses their likely significance.
Still images or video footage may be saved as part of the record.
6. The findings are explained
The property owner is given an explanation of what has been found and what action may be appropriate.
This could involve cleaning, monitoring, a local repair, relining, excavation or pipe replacement.
CJ Groundworks provides drainage investigation and repair services across Sussex, East Sussex, Surrey and Kent, including CCTV drain surveys and drain jetting.
Does every drain need cleaning before a survey?
Not necessarily.
A relatively clear drain may be inspected without extensive cleaning. However, deposits on the pipe walls can hide cracks and joints, while standing debris can prevent the camera from travelling through the system.
Cleaning may be necessary where the drain contains:
- Grease
- Silt
- Scale
- Tree roots
- Building debris
- Sewage deposits
- Mud or gravel
The purpose of the survey matters as well.
If the objective is simply to locate an obstruction, the camera may be inserted before cleaning. If the aim is to assess the full structural condition of the pipe, cleaning first usually provides a more reliable view.
What information is included in a drainage survey report?
The level of detail varies depending on the survey and the client’s requirements.
A basic inspection may provide a verbal explanation and footage. A more detailed survey may include:
- The surveyed pipe route
- Pipe sizes and materials where visible
- Access points used
- Direction of flow
- Recorded defects
- Approximate defect locations
- Images from the inspection
- Video footage
- Observations about pipe condition
- Recommended next steps
A clear report helps distinguish between urgent defects and issues that can be monitored.
For example, a minor joint defect may not require immediate excavation if it is not affecting performance. A collapsed section causing sewage to back up is more likely to require prompt repair.
Can the survey locate the exact position of a fault?
The camera system can often measure the distance travelled from the access point.
Additional locating equipment may be used to identify the camera’s position from above ground. This is particularly useful where the drain runs beneath a garden, driveway or building.
Accurate fault location can reduce the amount of excavation required.
Instead of opening a long trench to search for the damaged section, the contractor may be able to target a much smaller area.
Can a CCTV survey prevent unnecessary excavation?
Yes. One of the main benefits of a camera survey is that it can reduce guesswork.
Without internal footage, several different problems can produce similar symptoms. A recurring blockage might be caused by grease, roots, a displaced joint or a collapsed pipe.
Excavating before confirming the cause can result in unnecessary disruption.
A CCTV survey may show that the drain only needs:
- High-pressure jetting
- Root cutting
- Scale removal
- A local patch repair
- Relining
- A targeted replacement section
It may also confirm that excavation is necessary, but the work can be focused on the affected area.
This is especially valuable where drains run beneath:
- Patios
- Driveways
- Gardens
- Commercial yards
- Internal floors
- Roads
- Landscaped areas
What is the difference between a blockage and a structural defect?
A blockage restricts the flow through a pipe but does not always mean that the pipe itself is damaged.
Common blockage materials include:
- Grease
- Hair
- Wipes
- Food waste
- Silt
- Scale
- Foreign objects
- Construction debris
A structural defect affects the physical condition or position of the drainage pipe.
Examples include:
- Cracks
- Broken pipe sections
- Collapsed drains
- Deformed pipes
- Displaced joints
- Root entry points
- Poor gradients
The two issues can be connected.
A damaged joint may catch wipes or debris, causing a blockage. Cleaning the drain removes the immediate obstruction but does not repair the joint. The blockage may therefore return.
A CCTV survey helps identify whether cleaning alone is likely to provide a lasting solution.
What happens after a defect is found?
The recommended action depends on the type, location and seriousness of the defect.
Possible solutions include:
Drain jetting
High-pressure water is used to remove grease, silt, scale and other deposits.
This may be sufficient where the pipe is structurally sound.
Root cutting
Specialist equipment can remove roots from inside the pipe.
The entry point may still need repair to prevent regrowth.
Local repair
A damaged section can sometimes be exposed and replaced without renewing the entire drain run.
This may be suitable where the defect is limited to one area.
Drain relining
Some pipes can be repaired internally by installing a liner that forms a new surface inside the existing drain.
Suitability depends on the pipe condition, diameter and type of defect.
Full replacement
A heavily collapsed, badly deformed or extensively damaged drain may need to be excavated and replaced.
The surrounding ground, access and nearby structures will influence how the work is carried out.
Can a survey inspect surface water drains?
Yes. CCTV cameras can inspect both foul water and surface water drainage where suitable access is available.
Surface water systems can develop problems caused by:
- Silt
- Leaves
- Root intrusion
- Collapsed pipes
- Poor connections
- Damaged soakaway pipes
- Debris from roofing or building work
- Ground movement
A surface water drain may appear to work during light rain but back up during heavier weather.
The survey can help determine whether the issue lies in the pipework, an inspection chamber, the final discharge point or the wider capacity of the system.
Can off-mains drainage be surveyed?
Drainage pipes serving septic tanks, cesspits and sewage treatment plants can also be inspected with CCTV equipment.
The survey may be useful where:
- Wastewater is backing up towards the property
- The inlet pipe repeatedly blocks
- Ground movement is suspected
- Roots may have entered the pipe
- A treatment plant is not receiving flow correctly
- A property owner is planning replacement work
The camera survey normally focuses on the connecting drainage pipework rather than inspecting every internal component of the tank or treatment unit.
CJ Groundworks installs septic tanks, cesspits and sewage treatment plants for properties that require off-mains drainage.
What can limit a CCTV drain survey?
A camera inspection is highly useful, but it is not always able to reach every part of a drainage system.
Possible limitations include:
- No accessible entry point
- A complete blockage
- A collapsed pipe
- Very small pipework
- Tight bends
- Heavy deposits
- Standing sewage
- Poorly positioned chambers
- Multiple unrecorded connections
If the camera cannot pass through a section, the contractor may try another access point or recommend cleaning first.
In some cases, a small amount of excavation may be needed to create access or confirm the exact nature of the defect.
The survey should be treated as one part of the drainage investigation rather than a guarantee that every hidden condition will be visible.
How long does a CCTV drain survey take?
The time required depends on the size and complexity of the system.
A short domestic drain run with good access may be inspected relatively quickly. A larger property, commercial site or drainage network with multiple branches can take longer.
Factors that affect the survey time include:
- Number of access points
- Pipe length
- Blockages
- Cleaning requirements
- Number of connections
- Pipe condition
- Site access
- Whether a written report is required
It is more important for the survey to be thorough than to complete it within an arbitrary time.
How should you prepare for a drain survey?
Property owners can help by making known access points available.
Before the appointment:
- Move vehicles away from inspection covers
- Remove pots or furniture from access areas
- Avoid covering chambers with temporary materials
- Note where symptoms occur
- Record when the issue is worst
- Mention recent building or landscaping work
- Provide any existing drainage plans
Avoid continuing to use appliances if sewage is already backing up.
Adding more wastewater can worsen the blockage and make the area less safe to inspect.
Frequently Asked Questions
Will a CCTV drain survey damage the pipe?
The camera is designed for drainage inspection and should not damage sound pipework when used correctly. A severely weakened or collapsed pipe may prevent the camera from passing through.
Can a survey find a hidden drain connection?
It may reveal side connections and changes in flow direction. Further tracing or locating work can sometimes help establish where the connection runs above ground.
Do I need a CCTV survey for every blocked drain?
No. A simple one-off blockage may be cleared without a survey. A camera inspection is particularly helpful when blockages recur, several drains are affected or structural damage is suspected.
Can the camera see leaks?
The survey may show cracks, open joints, water entering the pipe or other evidence of leakage. Not every small leak is visible, particularly if the pipe is dirty or the defect is beneath standing water.
Will the survey tell me whether the whole drain needs replacing?
It can provide strong evidence about the pipe’s condition. The contractor can then recommend whether cleaning, local repair, relining or replacement is the most appropriate response.
Understanding what is happening below ground
A CCTV drain survey provides a practical way to inspect underground drainage without immediately digging up floors, gardens or driveways.
The camera can reveal blockages, cracks, displaced joints, roots, standing water and collapsed sections. This information helps identify the cause of the problem and makes it easier to choose an appropriate repair.
A survey is particularly worthwhile where a blockage keeps returning, drainage problems are affecting several appliances, building work is planned or there are signs of underground leakage or movement.
By locating and assessing the fault first, unnecessary excavation can often be avoided. Where excavation is required, the work can be targeted more accurately.
CJ Groundworks provides CCTV drain surveys, drain jetting, repairs and wider drainage solutions for domestic, commercial, industrial and rural properties across Sussex, East Sussex, Surrey and Kent.
Call 0140 373 3214 or email chris@cjgroundworks.com to discuss a drainage problem.
Find out more: CJ Groundworks
