Structural Defect Survey
A focused structural inspection for properties with suspected structural problems — cracks, movement, subsidence, heave, wall tie failure or roof spread. Our structural defect survey provides a detailed structural assessment, diagnoses the cause and severity of the defect, and delivers clear, prioritised recommendations for remedial works.
Whether you have noticed cracking, doors that no longer close, sloping floors or bowing walls, our experienced surveyors use specialist diagnostic techniques to determine whether the movement is historic and stable, or active and progressive — so you know exactly what you are dealing with and what needs to be done.
Structural Defect Survey
Our Home Surveyor & Property Valuer Accreditation & Professional Membership
Our Structural Defect 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 Structural Defect Survey?
A structural defect survey is a focused, specialist structural inspection commissioned when a property shows signs of structural distress — cracking, movement, subsidence, heave, wall tie failure or roof spread. Unlike a standard home survey which provides a general overview of the property's condition, a structural defect survey zeroes in on the suspected structural issue, diagnoses its cause and severity, and provides a detailed specification for remedial works.
What It Covers
- Detailed crack analysis — width, pattern, location, orientation and probable cause
- Diagnosis of whether structural movement is historic and stable or active and progressive
- Assessment for subsidence, heave, settlement and landslip including drainage and vegetation review
- Wall tie inspection for cavity wall tie corrosion or failure using a borescope where indicated
- Roof structure inspection — trusses, purlins and timbers checked for spread, deflection or failure
- Lintel, beam and load-bearing element assessment above openings and within the structure
- A detailed written report with findings, photographs, diagnosis and a remedial works specification
What It Does Not Cover
- A full building survey of the entire property — this is a focused structural investigation
- A market valuation or reinstatement cost assessment of the property
- Testing of electrical, gas, plumbing or drainage installations
- Guaranteed diagnosis behind concealed areas or within the building fabric without opening up
- Carrying out the actual remedial or structural repair works — we diagnose and specify only
When Should You Commission a Structural Defect Survey?
A structural defect survey is the right course of action when you have specific concerns about the structural integrity of a property. Here is how to tell if it suits your circumstances.
Suitable For
- Properties with visible cracking
- Suspected subsidence or ground movement
- Wall tie corrosion or failure in cavity walls
- Roof spread or sagging
- Lintel failure above windows or doors
- Bowing or leaning walls
Not Suitable For
- Properties with no structural concerns
- General pre-purchase surveys (these include a structural check but are not specialist investigations)
Not sure whether you need a structural defect survey or a full building survey? Speak to a surveyor for free, no-obligation advice.
What Is Included in a Structural Defect Survey
Every structural defect survey we produce includes the following as standard.
Crack Analysis
Detailed examination of cracks — width, pattern, location and probable cause. We measure crack width precisely, record the pattern and orientation, and assess whether the cracking is through the masonry units or following mortar joints, all of which informs the diagnosis.
Structural Movement Assessment
Diagnosis of whether movement is historic and stable or active and progressive. We look for tell-tale signs such as stepped cracking, differential movement between elements, distortion of openings and recent movement indicators that tell us whether the issue is ongoing.
Subsidence Investigation
Assessment for subsidence, heave, settlement and landslip with drainage and vegetation review. We examine the external environment — trees, drains, ground levels and soil conditions — to identify the likely cause of any ground movement affecting the structure.
Wall Tie Inspection
Examination for cavity wall tie corrosion or failure using a borescope where indicated. Wall tie failure is a common cause of cracking in cavity-walled properties built between the 1930s and 1970s, and can lead to progressive structural deterioration if not addressed.
Roof Structure Check
Inspection of roof timbers, trusses and purlins for signs of spread, deflection or failure. Roof spread can push external walls outwards and cause cracking at ceiling level — our inspection identifies the root cause and the remedial work required.
Remedial Recommendations
Clear specification of structural repairs, underpinning or monitoring required. Our report provides a prioritised schedule of works that you can take to structural engineers, builders or specialist contractors for comparable quotes.
How the Structural Defect Survey Process Works
From enquiry to report — straightforward and transparent.
Get a Quote
Contact us with the property details and a description of the structural concerns you have noticed. We respond within 24 hours with a fixed-price quote tailored to the property and the suspected defect.
Book the Inspection
Choose a convenient date. We typically schedule within 5–10 working days of your instruction, subject to access and availability. We can often accommodate urgent cases at shorter notice — just let us know.
Surveyor Inspects
The surveyor attends the property and carries out a thorough structural inspection, typically taking 2–4 hours depending on the size of the property and the nature of the suspected defects. You are welcome to be present and ask questions throughout.
Receive Your Report
Your detailed structural defect report — including findings, crack analysis, photographs, diagnosis and a remedial works specification — is delivered within 5–7 working days. Any urgent safety concerns are communicated on the day.
Specialist Equipment We Use for Structural Surveys
We use professional-grade diagnostic equipment to assess structural defects accurately, ensuring our diagnosis is based on objective evidence rather than visual inspection alone.
Crack Monitoring Gauge (Tell-Tale)
A precision crack monitor fixed across a crack to track whether it is widening, narrowing or stable over time. Essential for distinguishing between active and historic movement when the survey cannot determine this from a single inspection.
Digital Inclinometer
A precision instrument that measures the angle of lean or tilt in walls and structural elements. Used to quantify wall bowing and monitor changes over successive inspections.
Borescope
A flexible camera probe that can be inserted into cavities, wall ties and hidden voids to inspect structural elements that are not visible from the surface — such as cavity wall ties, embedded beams and concealed lintels.
Moisture Meter
A calibrated electronic moisture meter used to check whether damp is contributing to the structural defect — for example, corroded wall ties are often associated with cavity damp, and timber decay may result from persistent moisture ingress.
Laser Measure
A digital laser distance meter used to take precise measurements of deflection, distortion and dimensional changes across the structure, providing objective data to support the diagnosis.
High-Resolution Camera
A professional-grade camera used to capture detailed photographs of all structural defects, including close-ups of crack patterns, wall tie condition, roof structure and external defects for inclusion in the report.
Signs You May Need a Structural Defect Survey
Recognising the early warning signs of structural problems can save you significant expense and stress. Here are the most common indicators that a property may have a structural defect requiring specialist investigation.
Cracking
Cracks wider than 5mm, cracks that are wider at one end than the other (tapered), diagonal or stepped cracks radiating from the corners of doors and windows, and cracks that pass through bricks or blocks rather than following mortar joints are all potential indicators of structural movement. Hairline cracks that follow mortar joints are usually cosmetic and not a cause for concern.
Key indicator: cracks that have appeared suddenly or widened noticeably over weeks or months suggest active movement.
Distortion
Doors and windows that stick, jam or will not close properly, particularly if they previously operated correctly, can indicate that the surrounding structure has moved. Sloping or uneven floors, particularly where the slope is localised rather than consistent across the whole floor, can indicate localised structural settlement or joist failure.
Key indicator: doors that bind at the top on one side suggest the frame has gone out of square — usually from structural movement.
Deformation
Visible bowing or leaning of external walls, particularly gable walls or parapets, roof sagging or ridgeline distortion, and bulging at first-floor or ceiling level can all indicate structural deformation. In cavity-walled properties built from the 1930s onwards, horizontal or stepped cracking at approximately 450mm vertical intervals may indicate wall tie failure.
Key indicator: bowing that is visible to the naked eye is rarely trivial — it almost always warrants structural investigation.
Common Structural Defects We Investigate
Understanding the most common structural defects helps you recognise when a property may need specialist attention. Here are the issues we most frequently diagnose.
Subsidence
Downward movement of the ground supporting the building, typically caused by clay shrinkage (particularly in drought conditions affecting properties on clay soils), tree root activity extracting moisture from the soil, or leaking drains washing away fine soil particles. Subsidence usually manifests as diagonal cracking, wider at the top than the bottom, often concentrated near windows and doors. The crack pattern typically follows the path of least resistance through the masonry.
Common in: properties on clay soils, particularly in areas with mature trees close to the building. Clay shrinkage subsidence is especially prevalent across parts of Bedfordshire, Cambridgeshire and Hertfordshire.
Wall Tie Failure
Cavity wall ties are metal connectors that tie the inner and outer leaves of a cavity wall together. In properties built before 1981, wall ties were typically made from mild steel with limited or no corrosion protection. Over decades, moisture in the cavity can cause these ties to corrode. As steel corrodes it expands — sometimes by up to 10 times its original thickness — and this expansion can crack the mortar joints horizontally, causing the outer leaf to bulge or bow outwards.
Common in: cavity-walled properties built between the 1930s and early 1980s. Horizontal cracking at regular vertical intervals is the classic tell-tale sign.
Roof Spread
Roof spread occurs when the weight of the roof covering — particularly heavy materials such as concrete tiles that have replaced lighter original slates — pushes the rafters downwards and outwards at the eaves. This outward thrust can push the tops of the supporting walls outwards, causing horizontal cracking at ceiling level where the wall meets the ceiling, and bulging or leaning of the external walls at high level. The condition is often progressive and worsens over time if not addressed.
Common in: older properties where lightweight original roof coverings have been replaced with heavier modern tiles without strengthening the roof structure.
Structural Defect Survey Questions
When should I commission a structural defect survey?
You should commission a structural defect survey whenever you see signs of structural movement or distress in a property — particularly cracking wider than 5mm, cracks that are wider at the top than the bottom, diagonal cracks around doors and windows, doors and windows that stick or will not close, sloping or uneven floors, or visible bowing or leaning of walls. A standard home survey will flag these issues but may not provide the detailed structural diagnosis and repair specification you need. A structural defect survey gives you a definitive answer and a clear plan.
Is cracking always a sign of a serious structural problem?
No. Most cracking in buildings is cosmetic and results from thermal expansion and contraction, minor settlement or plaster shrinkage. However, some cracking patterns indicate serious structural movement. Key warning signs include: cracks wider than 5mm, cracks that are wider at one end than the other (tapered), diagonal cracks radiating from the corners of doors and windows, cracks that pass through bricks or blocks rather than following mortar joints, and cracks that have appeared or widened recently. A structural defect survey distinguishes between cosmetic cracking and structural movement.
Do you use specialist equipment for structural surveys?
Yes. Depending on the nature of the suspected defect, we may use: a borescope for inspecting cavities and hidden voids, a crack monitoring gauge (tell-tale) to track whether cracks are moving, a digital inclinometer to measure wall lean, a moisture meter to check for damp-associated structural issues, and in some cases we may recommend further investigations such as a CCTV drain survey or a structural engineer's calculation. We will explain what equipment is needed and why before proceeding.
How long does a structural defect survey take?
A structural defect survey typically takes between 2 and 4 hours on site, depending on the size of the property and the nature of the suspected defects. The surveyor examines all accessible parts of the structure in detail and the report is delivered within 5–7 working days. If we identify an urgent safety concern we will tell you on the day.
Get a Fixed-Price Structural Defect Survey Quote
Free, no-obligation quote within 24 hours. Independent, impartial advice from experienced surveyors who do not contract for remedial works.