Drainage Survey
A specialist drainage survey inspecting foul and surface water drainage systems using CCTV camera technology, manhole inspections, gully assessments and soakaway testing. We assess pipe condition, identify blockages, root ingress, collapsed drains and compliance with current building regulations, providing a comprehensive report on the condition of your drainage network.
Drainage defects can cause subsidence, damp, structural damage and environmental contamination — yet the drainage system is one of the least inspected parts of any property. Our drainage survey gives you certainty about what is happening below ground, whether you are buying, selling or investigating a specific problem.
Drainage Survey
Our Home Surveyor & Property Valuer Accreditation & Professional Membership
Our Drainage Surveys are carried out by qualified surveyors who belong to the professional bodies that set UK property standards. Every report is prepared to recognised guidance and is completely independent, so you can rely on the findings when you buy, sell or value a home.
What Is a Drainage Survey?
A drainage survey — also called a CCTV drain survey, drain inspection or drainage condition assessment — is a specialist inspection of the below-ground foul and surface water drainage network serving a property. Using a waterproof, high-resolution camera fed through the pipework, the survey produces a real-time video record of the internal condition of every accessible drain run, together with a written report identifying defects such as cracks, displaced joints, root ingress, blockages, scale build-up and collapsed sections. It is the only reliable way to assess the condition of below-ground drainage without excavation.
What It Covers
- CCTV camera survey of all accessible foul and surface water drain runs, producing a video record and still images of every defect identified
- Manhole and inspection chamber survey — recording chamber type, depth, construction material, benching condition and any evidence of surcharging or rat infestation
- Pipe condition grading using the standard 1-to-5 classification system — from serviceable (grade 1) to collapsed or fully blocked (grade 5)
- Gully and rainwater pipe assessment — checking that rainwater goods are correctly connected to the surface water drainage system and not cross-connected to the foul system
- Soakaway percolation testing where applicable, to assess whether soakaways are functioning correctly and meet current Building Regulations standards for surface water disposal
What It Does Not Cover
- A full structural survey of the property — the drainage survey is limited to the drainage system only
- A market valuation of the property
- Testing of gas or electrical installations
- Internal plumbing inspection above ground — sinks, baths, toilets and internal pipework are not covered
- Carrying out the actual drain repairs, relining or replacement — we diagnose and report, we do not contract
When Should You Commission a Drainage Survey?
A drainage survey is the right course of action in specific situations. Here is how to tell if it suits your circumstances.
Suitable For
- Homeowners experiencing recurring blocked drains, slow-running sinks and baths, or gurgling sounds from pipework
- Buyers purchasing an older property where the condition of below-ground drainage is unknown or suspected to be defective
- Property owners investigating the cause of subsidence where drain washout is a suspected contributory factor, or where insurers have requested a drainage survey
- Homeowners whose property has a private drainage system — septic tank, cesspit or package treatment plant — that may not have been inspected for years
- Owners of properties with large gardens or mature trees where root ingress into drainage is a known risk
- Anyone planning a house extension or significant landscaping that may affect, or be affected by, existing below-ground drainage runs
Not Suitable For
- A drainage survey alone is not a substitute for a full building survey where there are wider structural or condition concerns
- Properties where the drainage system is shared with neighbouring properties and access to all sections is not available — we can only survey what is accessible
- Internal plumbing issues such as leaking taps, faulty ball valves or toilet cistern problems — these are plumber-level issues, not drainage survey items
- Properties on a public sewer — the section of drain beyond your property boundary is the responsibility of the local water authority and is outside the scope of our survey
- If you need the drain repair, pipe relining or excavation work carried out — we diagnose and report, we do not contract
Not sure whether your drainage problem is above ground or below ground? Speak to a surveyor for free, no-obligation advice.
What Is Included in a Drainage Survey
Every drainage survey we produce includes the following as standard.
CCTV Drain Camera Survey
High-resolution colour CCTV camera fed through every accessible foul and surface water drain run, producing a continuous video recording and still images of every defect, joint and change in pipe material.
Pipe Condition Grading
Every section of drain graded from 1 (serviceable, no defects) to 5 (collapsed or fully blocked) using the standard industry classification, giving you a clear, at-a-glance picture of which sections need attention and how urgently.
Manhole & Chamber Survey
Every accessible manhole, inspection chamber, rodding point and back-inlet gully opened and inspected — recording chamber type, depth, construction, benching, and any signs of surcharging, vermin or structural defect.
Root Ingress Assessment
Identification and grading of any tree root ingress into the drainage system — recording the pipe section affected, the severity of the intrusion and the likely tree species responsible, where identifiable.
Gully & Rainwater Pipe Check
Assessment of all gullies, rainwater downpipes and surface water connections to confirm correct connection, adequate flow and no cross-connection to the foul drainage system (a common cause of pollution incidents).
Drainage Mapping
A dimensioned sketch plan showing the layout of the drainage network — pipe runs, manhole locations, flow directions and connection points — based on our on-site investigation and tracing.
Video Footage & Stills
Full video recording of the CCTV survey provided on a USB drive or via a secure download link, together with annotated still images of every significant defect. You keep the footage permanently — it is yours.
Defect Report & Repair Recommendations
A clear, prioritised report listing every defect identified — with its location, severity grade, recommended repair method (no-dig patch lining, full relining, localised excavation or replacement) and indicative cost guide.
How the Drainage Survey Process Works
From enquiry to report — straightforward and transparent.
Get a Quote
Contact us with the property details and the reason for the drainage survey — purchase, subsidence investigation, persistent blockages or planned extension. We respond within 24 hours with a fixed-price quote.
Book the Inspection
Choose a convenient date. We typically schedule within 5–10 working days of your instruction. We will let you know if any pre-survey preparation is needed, such as clearing access to manhole covers.
Surveyor Inspects
The surveyor attends with CCTV camera equipment and inspects every accessible drainage run, manhole, gully and connection — usually taking 1.5–3 hours depending on the size and complexity of the drainage network.
Receive Your Report
Your detailed drainage survey report — including video footage, still images, pipe condition gradings, a drainage layout plan and prioritised repair recommendations — is delivered within 5 working days.
The Three Most Common Drainage Defects We Find
Below-ground drainage defects are surprisingly common — even in properties where the drains appear to be functioning normally day to day. These are the three issues we encounter most frequently during our CCTV surveys.
Displaced & Open Joints
The most common defect in older drainage systems — particularly those constructed with traditional salt-glazed clayware pipes — is displaced or open joints between pipe sections. Over time, ground movement, vehicle loading, tree root pressure or simply poor original bedding can cause one pipe section to shift relative to the next, opening a gap at the joint. Water and solids escape through the gap into the surrounding ground — a process known as exfiltration — washing away fine soil particles and potentially creating voids that can lead to localised subsidence. Equally, groundwater and soil can enter the pipe through the same gap (infiltration), contributing to surcharging of the system during wet weather.
Common signs: no obvious above-ground symptoms, CCTV revealing gaps between pipe sections, evidence of soil or silt entering the pipe at joints, fine roots penetrating through open joints.
Root Ingress
Tree and shrub roots are naturally drawn to the moisture and nutrients present in drainage systems — even a microscopic gap at a pipe joint is enough for fine root hairs to enter. Once inside, roots proliferate within the pipe, forming a dense mat that traps solids, restricts flow and eventually causes complete blockage. Willows, poplars, ash, sycamore and leylandii are among the most aggressive species for root ingress. The problem is cumulative — a small amount of root ingress today will only get worse as the tree continues to grow. Left untreated, root ingress can fracture clay pipes and displace joints, requiring excavation rather than the simpler no-dig root cutting or patch lining that would have sufficed if caught early.
Common signs: slow-running drains, recurring blockages, gurgling sounds, CCTV showing a mass of fine roots within the pipe bore — often worse during the growing season.
Collapsed or Partially Collapsed Drains
The most serious drainage defect, a collapsed drain is one where the pipe crown (top) has fractured and fallen into the pipe bore, partially or completely obstructing flow. Collapses typically occur in older clayware or pitch-fibre pipes that have been subject to years of ground loading, corrosion, root pressure or bedding erosion. Pitch-fibre pipes — widely installed in the 1950s to 1970s as a cheaper alternative to clay — are particularly susceptible to delamination, where the inner layer of the pipe blisters and peels away, eventually collapsing inwards. A collapsed drain usually requires excavation and replacement of the affected section, although in some cases pipe relining — inserting a resin-impregnated liner that cures in place to form a new pipe within the old one — may be viable.
Common signs: complete loss of flow, persistent blockages that rodding does not clear, CCTV showing the pipe crown fractured and fallen into the bore, visible subsidence or depression in the ground above the drain run.
Specialist Equipment We Use
We use professional-grade drainage survey equipment — the same technology used by water authority contractors and civil engineering firms.
CCTV Crawler Camera
A self-propelled, remote-controlled crawler unit with a pan-and-tilt high-resolution colour camera, designed for surveying larger-diameter pipes (150 mm and above). The crawler can traverse long runs of pipework, recording continuous video with on-screen depth and distance measurement.
Push Rod Camera
A smaller, flexible camera head on a semi-rigid push rod, used for surveying smaller-diameter pipes (100 mm and 150 mm) and domestic drainage runs where a crawler unit is too large. The camera records continuously as it is pushed through the pipe.
Sonar Drain Tracer
A sonde (radio transmitter) attached to the camera head that transmits a signal detectable from the surface, allowing us to trace the exact line and depth of the drainage run and mark it on a site plan — essential for drainage mapping.
Manhole Lifting Keys
Heavy-duty lifting keys and bars for safely opening cast iron, concrete and composite manhole covers and inspection chamber lids without damaging the frame or surrounding paving.
Flow Meter & Dye Testing Kit
Fluorescent dye introduced into the drainage system to confirm flow direction, identify cross-connections between foul and surface water systems, and verify that rainwater goods are correctly connected to the surface water network.
Soakaway Percolation Test Kit
Equipment for conducting a BRE Digest 365 percolation test on soakaways — measuring the rate at which water drains away — to determine whether existing soakaways are functioning within acceptable limits for surface water disposal.
Drainage Survey Questions
What is a CCTV drainage survey and how does it work?
A CCTV drainage survey is an inspection of below-ground pipework using a waterproof, high-resolution camera that is fed through the drainage system. For domestic surveys, we typically use a push-rod camera — a flexible rod with a camera head that is manually pushed through the pipe, recording continuous video as it goes. For larger pipes, we use a crawler unit — a remote-controlled, self-propelled camera platform that can traverse long runs and pan and tilt to inspect specific defects. The camera records everything it sees, and the surveyor narrates the findings in real time, noting the location, type and severity of each defect. After the survey, you receive the full video footage, annotated still images of every significant defect, and a written report grading the condition of each section of pipe. The survey is non-destructive — no excavation is required — and typically takes 1.5 to 3 hours depending on the length and complexity of the drainage network.
Do I need a drainage survey when buying a house?
You are not legally required to have one, but a drainage survey is one of the most cost-effective pre-purchase investigations you can commission — particularly for older properties. A standard building survey does not include a CCTV inspection of below-ground drains, yet drainage defects can be among the most expensive to repair. A collapsed drain under a concrete floor or beneath a patio can cost several thousand pounds to excavate and replace. A drainage survey before exchange gives you certainty about the condition of the drainage system and — if defects are found — gives you the evidence you need to negotiate the price or request that the seller address the issue before completion. We recommend a drainage survey for any property built before the 1980s, any property with large trees within 10 metres of the building, and any property where the building survey has flagged concerns about drains or subsidence.
How much does a drainage survey cost?
Our drainage survey starts from £300 plus VAT for a typical residential property. The exact price depends on the number of drainage runs, the number of manholes and inspection chambers, whether soakaway testing is required and the accessibility of the drainage system. We provide a fixed-price quote within 24 hours of your enquiry — the price we quote is the price you pay, with no hidden extras, no travel surcharges and no additional fees for any location within our seven counties (Bedfordshire, Buckinghamshire, Cambridgeshire, Hertfordshire, Northamptonshire, Greater London and Oxfordshire). The price includes the full CCTV video footage and still images, which you keep permanently. We are entirely independent — we do not carry out drain repairs, relining or excavation — so our report is impartial and unbiased.
What happens if you find a defect — will you fix it?
No — we do not carry out drainage repairs, pipe relining, root cutting or excavation work. Our role is entirely diagnostic: we identify and grade defects and provide clear recommendations on the appropriate repair method. This separation between diagnosis and repair is fundamental to our independence — we have no financial incentive to recommend repairs that are not needed. Our report provides enough detail for you to obtain comparable quotes from at least three competent drainage repair contractors. We are happy to review the quotes you receive and offer an opinion on whether the proposed works match our recommendations. For no-dig repairs — such as patch lining or full-length cured-in-place pipe (CIPP) relining — we can explain what the process involves and what to look for in a competent contractor.
How long does a drainage survey take on site?
A drainage survey typically takes between 1.5 and 3 hours on site, depending on the size of the property, the number of drainage runs and how many manholes and inspection chambers need to be accessed. A straightforward survey on a modern property with three or four manholes and a simple drainage layout may take 1.5 hours. A larger or older property with multiple drainage runs, a septic tank or private treatment plant, or complex drainage history may take up to 3 hours. The time is spent lifting and inspecting each manhole, setting up the CCTV equipment at each access point, feeding the camera through each drain run, and recording the findings. You are welcome to be present — many clients find it illuminating to watch the CCTV footage on the monitor in real time as the surveyor narrates the findings.
Do you offer drain mapping and tracing?
Yes — drain mapping is included as standard in our drainage survey. Using a sonde (radio transmitter) attached to the CCTV camera head, we trace the exact line and depth of each drainage run from the surface and mark it on a dimensioned sketch plan. This is particularly valuable for properties where the drainage layout is not documented — which is the case for the vast majority of pre-1990s properties — and for anyone planning an extension, conservatory, garage or significant landscaping that might encroach on, or require diversion of, existing drainage runs. The drainage map is included in your survey report at no additional cost. We cover all seven of our counties: Bedfordshire, Buckinghamshire, Cambridgeshire, Hertfordshire, Northamptonshire, Greater London and Oxfordshire.
Get a Fixed-Price Drainage Survey Quote
Free, no-obligation quote within 24 hours. Independent, impartial advice with no ties to drainage repair or relining contractors.