Structural problems are every homebuyer's nightmare - hidden defects that surface after purchase, costing tens of thousands in repairs. The panel of chartered surveyors at Survey Merchant UK share expert guidance on identifying structural issues during property viewings, helping you avoid expensive mistakes and make informed buying decisions.
Why Spotting Structural Problems Matters
As CIOB, RPSA and/or RICS qualified building surveyors, the panel inspects thousands of properties annually. Many structural problems aren't immediately obvious to untrained eyes. What looks like minor cracking might indicate serious subsidence. That slight slope in floors could signal foundation failure. Understanding warning signs helps you:
- Avoid costly surprises - Structural repairs often cost £10,000-£50,000+
- Negotiate lower prices - Identified problems strengthen negotiating positions
- Make informed decisions - Know what you're buying before committing
- Plan future costs - Budget for necessary repairs and works
- Request professional surveys - Know when to call the panel of chartered surveyors
While professional building surveys from the panel of qualified surveyors remain essential, knowing what to look for during viewings helps you shortlist properties wisely and ask the right questions.
Understanding Different Types of Structural Problems
The panel of chartered building surveyors categorize structural issues into several types. Understanding these helps you recognize warning signs:
1. Subsidence
Subsidence occurs when ground beneath foundations sinks or moves, causing buildings to settle unevenly. CIOB, RPSA and/or RICS surveyors identify subsidence as one of the most serious and expensive structural problems. Clay soils are particularly susceptible - they shrink when dry and swell when wet, causing seasonal movement.
Common subsidence causes:
- Tree roots removing moisture from clay soils
- Leaking drains washing away supporting soil
- Prolonged dry weather shrinking clay
- Mining activity and ground cavities
- Inadequate foundations for ground conditions
2. Settlement
Settlement differs from subsidence - it's normal consolidation of ground under building weight. The panel of qualified surveyors explain that all properties settle slightly after construction. Settlement usually stabilizes within 10 years. Historic settlement evidenced by old, repaired cracks is less concerning than active, progressive movement.
3. Heave
The opposite of subsidence - ground swells and lifts foundations. Building surveyors typically see heave after large trees are removed. Without tree roots extracting moisture, clay soils rehydrate and expand, pushing foundations upward. Heave causes similar cracking to subsidence but pushes walls apart rather than pulling them together.
4. Structural Movement
Various factors cause structural movement beyond ground issues. Chartered surveyors investigate:
- Wall tie failure in cavity walls
- Lintel failure over openings
- Roof spread pushing walls outward
- Floor failure causing wall movement
- Poor alterations and modifications
- Thermal and moisture-related movement
The Warning Signs: What to Look For
CIOB, RPSA and/or RICS qualified surveyors share the key warning signs during property viewings:
Cracking - Reading the Clues
Not all cracks indicate serious problems, but chartered building surveyors assess cracking carefully. Understanding crack characteristics helps determine severity:
Crack Width Classification
- Hairline (< 1mm) - Usually minor, often cosmetic shrinkage
- Fine (1-5mm) - May indicate movement, monitor for changes
- Moderate (5-15mm) - Requires investigation by the panel of qualified surveyors
- Severe (15-25mm) - Serious structural concern needing expert assessment
- Very Severe (>25mm) - Significant structural failure, immediate chartered surveyor inspection essential
Crack Patterns to Worry About
Building surveyors pay special attention to:
- Diagonal cracks - Stepping through brickwork in 45-degree patterns, particularly near corners or openings. These often indicate subsidence or settlement.
- Tapered cracks - Wider at one end than the other, suggesting progressive movement in one direction. Classic subsidence indicator.
- Horizontal cracks - At ceiling/wall junctions or running along walls, potentially indicating roof spread or lintel failure.
- Vertical cracks - Straight down from corners of openings or at wall junctions, possibly thermal movement or foundation issues.
- Multiple cracks - Several cracks in different areas suggest widespread problems requiring urgent chartered surveyor assessment.
Red Flag: Progressive Cracking
Look for recently repaired cracks that have reopened. Fresh plaster or paint over cracks that have reappeared indicates ongoing movement. The panel of qualified surveyors consider this a serious warning sign requiring immediate professional investigation. Active movement needs addressing before purchase.
Complete Crack Assessment Guide
| Crack Type | Likely Cause | Severity Level | Action Required | Typical Repair Cost |
|---|---|---|---|---|
| Hairline diagonal through brickwork | Thermal movement, minor settlement | Low - Monitor | Repoint and monitor for 6-12 months | £200-£500 |
| Stepped cracks (5-10mm) near corners | Differential settlement, possible subsidence | Medium - Investigate | Professional surveyor inspection, monitoring | £5,000-£15,000 (if underpinning needed) |
| Tapered cracks (wide top, narrow bottom) | Active subsidence | High - Urgent | Immediate structural engineer assessment | £15,000-£50,000+ (underpinning) |
| Horizontal cracks at ceiling junction | Roof spread, lintel failure | Medium-High | Structural survey, roof inspection | £3,000-£10,000 (roof remediation) |
| Vertical cracks from window corners | Lintel failure, thermal stress | Medium | Survey to assess lintel condition | £1,500-£4,000 (per lintel replacement) |
| Multiple fine cracks (spider web pattern) | Plaster shrinkage, render failure | Low - Cosmetic | Replaster or re-render | £1,000-£3,000 |
| Wide cracks (15mm+) with displaced bricks | Severe subsidence or wall tie failure | Very High - Critical | Immediate engineer input, structural repairs | £20,000-£75,000+ |
| Cracks following mortar joints | Foundation movement, wall settlement | Medium-High | Structural survey, monitoring | £8,000-£25,000 (if stabilization needed) |
| Internal/external cracks aligned | Through-thickness structural movement | High | Full structural investigation essential | £10,000-£40,000 |
| Cracks with recent repainting | Active ongoing movement (covered up) | High - Red Flag | Walk away or demand full investigation | £15,000-£60,000+ (if structural) |
Pro Tip: Measuring Cracks
Carry a coin during property viewings for quick crack width assessment:
- 1p coin (1.65mm thick): If it fits in crack, you're at moderate concern level
- £1 coin (2.8mm thick): If it fits, professional surveyor needed
- 10p coin (1.85mm thick): Good middle-ground measurement tool
- Pencil width (6-7mm): If pencil fits, serious structural investigation essential
Remember: It's not just width - crack pattern, location, and alignment matter as much as size. Chartered surveyors assess all factors holistically.
External Wall Issues
The panel of chartered building surveyors examine external walls thoroughly. Warning signs include:
- Bulging or bowing walls - Walls curving outward, particularly on gable ends or long walls without support
- Leaning walls - Walls not truly vertical, visible by looking along their length
- Separated walls - Gaps appearing where walls meet at corners
- Stepped cracking in brickwork - Following mortar joints in stair-step patterns
- Displaced or sliding bricks - Individual bricks moved from original positions
- Cracked or displaced lintels - Over windows and doors
Internal Signs of Structural Problems
Inside properties, the panel of CIOB, RPSA and/or RICS surveyors look for:
Doors and Windows
- Sticking doors - Doors suddenly becoming difficult to open/close without obvious cause
- Gaps around frames - Increasing gaps between frames and walls
- Windows won't close - Particularly upper floor windows in older properties
- Diagonal frame distortion - Frames no longer square, causing operational problems
Floors
The panel of qualified surveyors assess floor conditions carefully:
- Sloping floors - Use a marble or ball - does it roll? Significant slopes indicate structural movement
- Bouncy floors - Excessive movement when walking suggests joist problems
- Cracks in floor finishes - Particularly if aligned with wall cracks
- Separation from walls - Gaps appearing where floors meet walls
Ceilings
- Sagging ceilings - Visible dips or undulations
- Cracks running across rooms - Especially if aligned with external wall cracks
- Bulging plasterwork - Ceiling plaster losing adhesion and detaching
Roof Problems
The panel of chartered building surveyors examine roofs for structural concerns:
External Roof Signs
- Sagging ridge lines - Visible dips in roof apex when viewed from distance
- Slipped or missing tiles/slates - Indicating roof movement or deterioration
- Bulging roof slopes - Undulations in roof planes suggesting structural failure
- Leaning chimneys - Chimneys not vertical, potentially dangerous
Internal Roof Space Signs
If you can access the loft, the panel of qualified surveyors recommend looking for:
- Roof spread - Ridge pushed upward, rafters pushed outward at eaves
- Broken or sagging timbers - Particularly purlins and rafters
- Cut or removed structural members - Previous alterations weakening structure
- Daylight through roof covering - Holes or displaced tiles/slates
- Water staining on timbers - Indicating leaks and potential rot
Tree-Related Structural Risks
Trees near properties cause frequent structural problems. Our panel of chartered surveyors assess tree risks during building surveys:
High-Risk Tree Species
Some trees pose greater subsidence risks on clay soils:
- Oak - Extensive root systems, high water demand
- Poplar - Fast-growing, thirsty trees
- Willow - Love water, roots seek it aggressively
- Elm - Deep roots and high water uptake
- Ash - Large root systems affecting wide areas
Safe Distance Guidelines
Our panel of CIOB, RPSA and/or RICS qualified surveyors use rough guidelines for tree distances:
- Trees should ideally be 1.5 times their mature height from properties
- High water demand species need greater distances on clay
- Multiple trees collectively pose greater risks
- Recently removed large trees may cause heave
If properties have large trees nearby, our panel of building surveyors strongly recommend professional surveys including specialist tree root investigations if subsidence is suspected.
Damp and Moisture-Related Structural Issues
While not always structural, damp problems often accompany or cause structural damage. Our panel of chartered surveyors investigate connections between damp and structural defects:
Rising Damp
Ground moisture rising through walls via capillary action. Our panel of qualified surveyors identify rising damp through:
- Tide marks on walls up to 1 meter high
- Peeling paint and damaged plaster
- Salt deposits and staining
- Musty odors
- Rotting skirting boards
Severe rising damp can compromise wall strength over time, particularly if associated with timber decay.
Penetrating Damp
Water penetrating through external walls from outside. Our panel of building surveyors find this causes structural problems when:
- Prolonged saturation freezes and damages brickwork
- Embedded timber elements (lintels, joists) rot
- Wall ties corrode and fail
- Render debonds and falls
Condensation vs. Structural Damp
Our panel of chartered surveyors distinguish condensation (lifestyle issue) from structural damp (building defect). Condensation appears on cold surfaces like windows and external walls, particularly in corners. Structural damp shows specific patterns related to defect locations. Professional surveys with moisture meters definitively diagnose damp sources.
Foundation and Ground Issues
While foundations are hidden, our panel of CIOB, RPSA and/or RICS qualified surveyors identify signs suggesting foundation problems:
Visible Foundation Issues
- Exposed foundations - Ground levels reduced, exposing normally-buried brickwork
- Foundation steps - Different foundation levels on slopes, with cracks at changes
- Settlement cracks near drains - Suggesting drain leaks undermining foundations
- Infilled ground - Properties on filled land prone to uneven settlement
Ground Investigation Triggers
Our panel of building surveyors recommend ground investigations when we find:
- Progressive subsidence or settlement
- Properties on clay soils with large trees
- Former commercial or industrial sites
- Made ground or landfill sites
- Mining areas or ground cavities
- Slopes and embankments
Age-Specific Structural Concerns
Different property ages have characteristic structural issues. Our panel of chartered surveyors explain what to watch for:
When to Walk Away vs. When to Investigate Further
Not all structural problems mean walking away. Our panel of qualified surveyors help clients decide when problems are manageable and when they're deal-breakers:
Warning Signs to Walk Away
- Widespread severe cracking - Multiple areas with wide, progressive cracks
- Obvious structural failure - Severely leaning walls, collapsed sections
- Active subsidence - Clear evidence of ongoing, progressive movement
- Dangerous structural elements - Leaning chimneys, unstable walls
- Undisclosed major repairs - Hidden structural works suggesting bigger problems
Problems Worth Investigating
Our panel of chartered building surveyors can assess and quantify these issues:
- Minor historic cracking - Old, repaired, stable cracks
- Isolated defects - Single issues in otherwise sound properties
- Repairable problems - Clear causes with known solutions
- Cosmetic issues - Superficial problems appearing worse than they are
Decision Matrix: Walk Away or Negotiate?
Use this decision guide when you spot structural problems:
| Problem Severity | Action | Typical Cost Impact |
|---|---|---|
| Minor cosmetic cracks | Proceed - factor in minor repair costs | £500-£2,000 |
| Moderate cracks, stable | Get Level 3 Survey - negotiate if needed | £3,000-£10,000 |
| Large cracks, active movement | Structural engineer report essential | £15,000-£50,000 |
| Severe structural failure | Walk away unless heavily discounted | £50,000-£150,000+ |
| Multiple severe issues | Walk away - too risky | Unquantifiable |
Remember: Even "minor" problems in wrong locations can be serious. Always get professional surveyor input before deciding.
Professional Survey Essential
Never rely solely on viewing observations for structural assessments. Our panel of CIOB, RPSA and/or RICS chartered surveyors use specialist equipment, extensive experience, and technical knowledge to properly diagnose structural problems. Professional building surveys from the qualified team provide definitive assessments, repair recommendations, and cost guidance. Don't risk your biggest investment - call 0204 579 8270 for expert building survey services.
Questions to Ask Sellers
If you spot potential structural problems, our panel of chartered surveyors recommend asking sellers:
- Are you aware of any structural issues with the property?
- Has the property had any structural repairs? When and by whom?
- Have you noticed any cracks appearing or worsening?
- Are there any guarantees or insurance policies for structural work?
- Have structural engineers surveyed the property?
- Are there any issues with nearby trees?
- Has the property suffered subsidence or settlement?
- What is the ground type/soil condition here?
- Have any underpinning or foundation works been done?
- Can you provide documentation of any structural works?
Sellers must disclose known material defects. Failure to disclose structural problems constitutes misrepresentation. Our panel of qualified surveyors have seen cases where buyers successfully claimed against sellers for non-disclosure.
The Value of Professional Building Surveys
While this guide helps you spot potential problems, professional surveys from our panel of CIOB, RPSA and/or RICS chartered surveyors remain essential:
What Our Building Surveyors Provide
- Expert assessment - Decades of experience identifying subtle problems
- Specialist equipment - Moisture meters, thermal cameras, endoscopes
- Technical knowledge - Understanding causes, implications, and solutions
- Comprehensive reports - Detailed findings with repair recommendations and costs
- Legal protection - Professional indemnity insurance covering our assessments
- Negotiation support - Evidence supporting price reductions
Our panel of qualified building surveyors spot problems you'll miss. Professional surveys typically cost £600-£1,500 but save thousands by identifying structural defects before purchase. Many clients have walked away from properties after our panel of chartered surveyors found serious problems, or negotiated £10,000-£30,000 price reductions based on our findings.
Summary: Your Structural Problem Checklist
During property viewings, our panel of chartered surveyors recommend checking:
Quick Viewing Checklist
- External walls: Cracks, bulges, leaning
- Internal walls: Crack patterns, recent repairs
- Doors/windows: Operation, gaps, distortion
- Floors: Slopes, bounce, separation
- Ceilings: Sagging, cracks, bulges
- Roof: Ridge lines, slopes, chimneys
- Trees: Large trees near property
- Damp: Staining, peeling, odors
- Ground: Slopes, drainage, exposure
- Extensions: Junction cracks, poor construction
Get Expert Structural Assessment
Spotted potential structural problems during viewings? Our panel of CIOB, RPSA and/or RICS chartered surveyors at Survey Merchant UK provide comprehensive building surveys identifying all structural issues, explaining causes and implications, and recommending repair solutions with cost guidance.
Operating across London, Birmingham, Manchester, and Bristol, our panel of qualified building surveyors deliver expert assessments protecting your property investment. Don't risk buying structural problems - get professional surveys from our experienced team.
Frequently Asked Questions
While you can identify obvious warning signs, many structural problems require professional assessment. Our panel of chartered building surveyors use specialist equipment, technical knowledge, and experience to detect issues hidden from untrained eyes. DIY inspections miss critical defects that could cost thousands in repairs.
Subsidence is very serious and can cost £10,000-£50,000+ to repair. However, not all movement indicates active subsidence. Our panel of CIOB, RPSA and/or RICS surveyors assess crack patterns, monitor movement, and identify causes. Historic subsidence that's been properly repaired may not be a deal-breaker, but active movement requires immediate attention and specialist investigation.
Not always. Fine hairline cracks under 1mm wide are often cosmetic settlement cracks. However, the building surveyors check crack width, location, and direction to determine severity. Diagonal cracks, stepped cracks in brickwork, or cracks wider than 3mm may indicate structural movement requiring professional investigation.
Not necessarily. Our panel of chartered surveyors provide repair cost estimates and advice on severity. Minor structural issues may be negotiable with sellers. Serious problems like active subsidence or foundation failure might justify walking away, but many structural defects are repairable. Professional advice helps you make informed decisions rather than emotional ones.
Costs vary enormously depending on the problem. Minor crack repairs cost £500-£2,000. Underpinning foundations costs £10,000-£50,000+. Roof structure repairs range from £3,000-£15,000. Our panel of building surveyors provide realistic repair cost estimates in survey reports, helping you negotiate prices or budget for necessary works.
Book Your Building Survey
Protect your property purchase with expert surveys from CIOB, RPSA and/or RICS chartered surveyors. Our experienced building surveyors identify structural problems you'll miss, providing comprehensive reports with repair recommendations and costs. Make informed decisions with professional guidance.
