MET SURVEYORS
Expert Advice on Property Matters
Crack Monitoring & Structural Movement Monitoring
Find Out Whether Cracks and Structural Movement Are Still Active
Cracks can tell us that movement has occurred.
What they do not always tell us is whether that movement happened years ago, has now stabilised, varies seasonally or is still continuing.
That is where crack monitoring and structural movement monitoring can be valuable.
Met Surveyors provides monitoring services across London and the Home Counties for properties affected by cracking, suspected subsidence, settlement, extension movement, sloping floors and other signs of structural movement.
For most new enquiries, we recommend beginning with a Specific Issue Survey from £695 + VAT.
If monitoring is considered appropriate during that inspection, the service can normally be upgraded while we are already at the property.
What Is Crack Monitoring?
Crack monitoring records movement across a crack over a period of time.
Monitoring gauges are installed across selected cracks and an initial baseline reading is recorded.
The gauges are then revisited at agreed intervals so that subsequent readings can be compared with the original measurements.
This can help establish whether the crack appears:
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Stable
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Continuing to move
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Increasing
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Opening and closing seasonally
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Moving vertically as well as horizontally
The results can provide useful evidence when deciding whether further investigation or repair is necessary.
Why Monitor Cracks?
A structural survey is normally based on the condition of the property at the time of inspection.
In many cases, the likely cause of cracking can be identified from the pattern, location and surrounding construction.
In other cases there simply is not enough evidence from one inspection to determine whether movement is continuing.
Monitoring can be particularly useful where:
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The age of the cracking is uncertain
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Cracks have previously been repaired and reopened
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Subsidence is suspected
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Settlement may still be taking place
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Movement appears seasonal
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An extension is moving differently from the original house
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Cracks appeared following prolonged dry weather
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Further evidence is required before deciding upon repairs
The purpose is to replace guesswork with a recorded history of movement.
What Is Structural Movement Monitoring?
Structural movement monitoring is broader than simply measuring one crack.
A building may display movement through a combination of different symptoms.
These can include:
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Changing crack widths
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Movement between different sections of a building
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Distortion around doors or windows
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Sloping floors
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Sinking floors
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Changes in floor level
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Movement around extensions
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Reopening previous repairs
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Changes to external masonry
Where appropriate, crack readings can therefore form part of a wider structural movement monitoring programme.
This can be useful where the concern involves possible subsidence, settlement, differential movement or movement
between old and new parts of a building.
Building Movement Monitoring
Buildings move for many different reasons.
Possible causes include:
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Normal settlement
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Differential settlement
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Thermal movement
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Shrinkage
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Changes in ground conditions
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Tree related ground movement
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Drainage defects
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Subsidence
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Structural alterations
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Movement between different foundation types
The objective of building movement monitoring is not simply to record that movement exists.
It is to establish how the building is behaving over time.
That information can then assist in deciding what should happen next.
Subsidence Monitoring
Where subsidence is suspected, monitoring can help establish whether cracking is changing.
Possible subsidence related factors may include:
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Shrinkable clay soil
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Long periods of hot and dry weather
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Mature trees
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Leaking drains
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Shallow foundations
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Different foundation depths
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Previous structural movement
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Local ground conditions
Monitoring does not, by itself, prove that subsidence is the cause.
It provides evidence about whether visible movement is continuing.
That information can then be considered alongside the construction, ground conditions and other available evidence.
How Does Crack Monitoring Work?
Monitoring normally begins by selecting suitable cracks that provide useful information about the movement being investigated.
Monitoring gauges are fixed across those cracks.
At the initial visit we record:
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Location of each monitoring point
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Baseline measurements
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Photographs
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Crack pattern
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Relevant structural observations
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Condition of nearby walls, floors and openings
The same points are then measured during subsequent visits.
The readings are compared with the baseline and with previous measurements.
What Does a Crack Monitoring Gauge Measure?
A typical crack gauge consists of two overlapping components fixed on opposite sides of a crack.
The graduated scale allows relative movement between the two sides to be recorded.
Depending upon the installation, this may help record:
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Horizontal movement
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Vertical movement
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Changes in crack width
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Relative displacement
The monitoring method selected depends upon the type and location of movement.
How Many Monitoring Gauges Are Needed?
There is no fixed number that is appropriate for every building.
The objective is to select enough monitoring points to provide useful evidence without unnecessarily monitoring every hairline crack.
The number required depends upon:
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Number of affected areas
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Pattern of cracking
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Size of the building
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Whether several elevations are affected
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Whether an extension is involved
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Complexity of the movement
Our standard programme is intended for a typical residential property with a limited number of representative monitoring locations.
Additional monitoring points can be quoted where required.
Start With a Specific Issue Survey
For most homeowners, the sensible first step is:
Specific Issue Survey From £695 + VAT
This allows us to inspect the property and establish what the cracking appears to represent.
Monitoring may not be necessary.
The problem may instead be consistent with:
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Minor settlement
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Plaster shrinkage
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Thermal movement
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Lintel movement
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Poor bonding
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Movement between an extension and the original building
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A localised floor defect
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Previous alterations
Where the available evidence is sufficient, there is little value in paying for months of monitoring.
The first inspection allows us to decide whether monitoring is justified.
Upgrade to Crack Monitoring During the Initial Survey
If monitoring is recommended during the Specific Issue Survey, it can normally be established during the same visit.
This means that while we are already at the property we can:
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Select appropriate monitoring locations
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Install the monitoring gauges
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Take the baseline measurements
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Record the initial photographs
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Establish the monitoring programme
This avoids the need for a separate setup visit.
Standalone Crack Monitoring Programme From £1,695 + VAT
Upgrade During Your Specific Issue Survey From £1,395 + VAT total / Save £300 + VAT
The initial survey becomes the first stage of the monitoring programme.
What Is Included in the Crack Monitoring Programme?
Our standard programme can include:
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Initial assessment of the reported concern
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Installation of crack monitoring gauges
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Baseline readings
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Baseline photographs
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Three scheduled return monitoring visits
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Measurement of each monitoring point
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Comparison with previous readings
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Assessment of recorded movement
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Final written monitoring report
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Recommendations regarding next steps
The programme may be adapted where a longer monitoring period or additional monitoring points are required.
How Long Should Structural Movement Be Monitored?
There is no single monitoring period suitable for every property.
Some localised issues may be assessed over several months.
Where possible subsidence or seasonal ground movement is involved, a longer period may be more useful because ground conditions can vary throughout the year.
The appropriate period depends upon factors including:
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Nature of the cracking
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Time of year
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Soil conditions
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Nearby vegetation
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Previous movement
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Initial monitoring results
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Extent of the problem
Where necessary, additional monitoring visits can be arranged after the standard programme.
What Happens at Each Monitoring Visit?
During the return visits we will normally:
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Inspect the monitoring gauges
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Record current readings
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Compare readings with the baseline
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Compare them with previous visits
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Photograph the monitored areas where appropriate
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Record visible changes to the cracks
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Note other relevant changes to the building
This creates a chronological record of movement.
What Happens at the End of the Monitoring Programme?
At the end of the agreed monitoring period, the readings are reviewed.
A written monitoring report can then explain whether:
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No measurable movement was recorded
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Limited movement was recorded
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Movement appears to be continuing
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Movement appears seasonal
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Further monitoring would be appropriate
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Additional investigation is recommended
The findings help determine the next logical stage.
Does No Recorded Movement Mean the Building Will Never Move Again?
No.
Monitoring records what happened during the monitoring period.
A property could behave differently at another time of year or following different weather conditions.
This is particularly relevant where seasonal ground movement is possible.
For that reason, the report should be read as evidence of the building's behaviour during the monitoring period rather than a permanent guarantee of stability.
Level Monitoring and Sloping Floors
Movement does not always show itself through cracks alone.
Some properties also display changes to floor levels.
Possible signs include:
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Sloping floors
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Sinking floors
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A change in level between rooms
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A difference in level between an extension and the original house
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Cracked floor slabs
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Gaps beneath skirting boards
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Doors dragging across the floor
Where floor movement is relevant, level measurements may form part of a wider structural movement assessment.
This can help establish whether changes to floor level correspond with other signs of building movement.
Movement Between an Extension and the Original House
Extensions are particularly common candidates for monitoring.
The extension and original building may have:
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Different foundations
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Different foundation depths
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Different ages
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Different materials
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Different rates of settlement
Cracking at the junction may therefore result from differential movement.
Where it is unclear whether that movement has stabilised, crack monitoring can provide useful evidence.
Monitoring After Hot Weather
Properties built on some clay soils can be affected by changing moisture levels.
Cracks may become more noticeable during or after prolonged dry weather.
Monitoring over a longer period can sometimes help establish whether movement:
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Continues
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Stabilises
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Changes seasonally
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Reverses partly during wetter conditions
This information can be useful where subsidence is being considered as a possible cause.
Reopening Cracks
A crack that has previously been repaired and later opens again can be particularly useful to monitor.
Repeated cosmetic repair does not establish why the crack keeps returning.
Monitoring can help determine whether movement is still occurring before another repair is undertaken.
Should Cracks Be Repaired Before Monitoring?
Normally, the monitored areas should remain accessible and undisturbed during the monitoring period.
If possible, photographs and measurements should be recorded before cosmetic repairs are carried out.
Once sufficient evidence has been collected and the likely cause is understood, repairs can be considered.
When Is Monitoring Not Appropriate?
Monitoring is not always necessary.
If the cause of a defect is already clear, it may be better to move directly to investigation or repair.
Similarly, if a property shows widespread and significant structural movement, a broader Structural Survey may be required before deciding whether monitoring is appropriate.
Examples include:
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Widespread cracking
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Several elevations affected
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Significant floor movement
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Several distorted openings
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Major structural alterations
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Obvious foundation concerns
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Several unrelated structural defects
The investigation should always match the scale of the problem.
When Is a Structural Survey More Appropriate?
A wider Structural Survey may be more suitable where:
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Cracking affects several areas
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Movement appears widespread
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Floors are also moving
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Several doors or windows are distorted
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Several elevations are affected
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Subsidence is strongly suspected
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The overall structural condition needs to be considered
A broader survey allows the building to be assessed as a whole rather than focusing only on selected cracks.
What If Movement Is Recorded?
Where measurable movement is identified, the next stage depends upon the circumstances.
Further investigation might include:
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Continued monitoring
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Structural Survey
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CCTV drainage investigation
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Trial holes
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Foundation investigation
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Ground investigation
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Arboricultural assessment
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Structural engineering input
Monitoring therefore helps determine whether further investigation is justified and where attention should be concentrated.
Buying a Property With Monitored Cracks?
Where a property has a history of movement, previous monitoring records can be extremely useful.
If available, purchasers should try to obtain:
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Previous crack monitoring results
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Structural reports
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Building Survey reports
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Insurance records
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Drainage reports
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Details of repairs
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Foundation investigation records
Where the position remains unclear, further structural advice may be appropriate before exchange of contracts.
Crack Monitoring Programme Prices
Specific Issue Survey From £695 + VAT
Recommended as the starting point where you have one defined structural concern.
Crack Monitoring Programme Upgraded During the Initial Survey From £1,395 + VAT total
Where monitoring is recommended and suitable monitoring points can be established during the initial visit.
Standalone Crack Monitoring Programme
From £1,695 + VAT.
Where a separate initial attendance is required to inspect the problem, install monitoring equipment and establish the baseline.
Additional gauges, additional visits or extended monitoring periods can be quoted separately where required.
Not Sure Whether You Need Crack Monitoring?
You do not need to decide before contacting us.
Send Met Surveyors:
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The property address
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Photographs of the cracking or movement
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A brief description of the problem
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When you first noticed it
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Whether it appears to be changing
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Details of previous repairs
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Photographs of any sloping or sinking floors
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Any previous survey or structural reports
For most enquiries, we recommend starting with a Specific Issue Survey from £695 + VAT.
If monitoring is required, you can then upgrade during the same visit to a Crack Monitoring Programme from £1,395 + VAT, saving £300 + VAT against commissioning the programme separately.
