MET SURVEYORS

Are Cracks in Walls Normal?

 

Yes. Many properties develop small cracks over time.

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Common causes include:

• Drying shrinkage in plaster

• Normal settlement

• Thermal movement

• Minor movement between different building materials

• Movement between new and old construction

• Previous decoration or plaster repairs

• Changes in humidity

• Minor seasonal movement

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Very fine cracks in plaster are common and are often cosmetic.

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However, cracking should be considered more carefully where it is new, becoming wider or accompanied by other signs of movement.

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Which Cracks Should You Worry About?

 

There is no single crack size that proves a serious structural problem.

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However, certain patterns are more likely to justify further investigation.

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These include:

• Cracks that are becoming wider

• Diagonal cracks around windows or doors

• Cracks that are wider at one end

• Cracking visible both inside and outside the property

• Previously repaired cracks that have reopened

• Cracks running through masonry rather than only plaster

• Cracking between an extension and the original house

• Cracking accompanied by sticking doors or windows

• Cracks associated with distortion to walls or openings

• Movement affecting several parts of the property

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If several of these signs are present together, it is sensible to obtain professional advice.

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Hairline Cracks

 

Very fine cracks are common in plaster and decorative finishes.

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They may appear:

• Around ceilings

• Above door frames

• Around plasterboard joints

• Where different materials meet

• Following redecoration

• In newly plastered rooms

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Hairline cracking does not automatically indicate a structural problem.

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The important factors are whether the crack is changing, whether it extends into the structure behind the plaster and whether there are other signs of movement nearby.

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Diagonal Cracks Around Doors and Windows

 

Diagonal cracking around openings is one of the patterns that homeowners often associate with subsidence.

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This is because doors and windows create weaker points within a wall where movement may become visible first.

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However, diagonal cracking can also result from:

• Normal settlement

• Lintel movement

• Thermal movement

• Poor construction

• Previous alterations

• Differential movement between materials

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The presence of a diagonal crack therefore does not confirm subsidence.

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The wider pattern needs to be considered.

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Cracks That Are Wider at One End

 

A tapered crack can sometimes indicate movement.

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Where one side of a crack is noticeably wider than the other, this may suggest that part of the structure has moved relative to another part.

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This can occur through settlement, differential movement or ground movement.

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If the crack is increasing in width or appears in several locations, further inspection may be advisable.

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Cracks Between an Extension and the Original House

 

Cracking where an extension joins the original property is extremely common.

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The extension and the original building may have:

• Different foundation depths

• Different foundation types

• Different materials

• Different ages

• Different rates of settlement

• Different thermal movement

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Minor cracking at the junction can therefore occur without there being a serious problem.

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However, wider or progressive cracking may indicate more significant movement and should be investigated.

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Cracks Following Hot or Dry Weather

 

Periods of prolonged dry weather can sometimes contribute to ground movement, particularly in areas with shrinkable clay soil.

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London and much of the South East contain areas of clay soil that can change volume as moisture levels change.

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This does not mean that cracks appearing after a dry summer automatically indicate subsidence.

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However, if cracking appears suddenly following prolonged dry conditions, especially where there are mature trees nearby, further assessment may be sensible.

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Cracks and Nearby Trees

 

Trees are often blamed when cracking appears, but the relationship is not always straightforward.

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Factors that may be relevant include:

• Tree species

• Tree size

• Distance from the building

• Ground conditions

• Foundation depth

• Location of the cracking

• Previous movement

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A tree close to a house does not automatically mean it is responsible for the movement.

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Where tree related movement is suspected, a more detailed structural or arboricultural assessment may be required.

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Can Leaking Drains Cause Cracks?

 

In some circumstances, yes.

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Leaking underground drainage can affect surrounding ground conditions and may contribute to movement.

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Where cracking occurs near drainage runs, inspection chambers or areas known to have drainage problems, further investigation may be recommended.

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This may include a CCTV drain survey.

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Cracks in Older Properties

 

Older properties often contain historic cracking.

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Victorian and Edwardian buildings, in particular, may have experienced movement over many decades.

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Some cracking may have stabilised long ago.

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The presence of an old crack does not necessarily mean that the building is currently moving.

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More important questions include:

• Has the crack changed recently?

• Has it been repaired before?

• Has the repair reopened?

• Are there other new cracks nearby?

• Are doors or windows beginning to stick?

• Is there visible distortion?

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Evidence of recent change is usually more significant than the presence of an old stable crack.

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Cracks in Newly Built or Recently Altered Properties

 

New buildings and extensions can also develop cracks as materials dry and the structure settles.

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Minor settlement and drying shrinkage may occur during the early life of a building.

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However, more substantial or progressive cracking can indicate:

• Inadequate foundations

• Poor structural detailing

• Defective workmanship

• Insufficient movement joints

• Differential movement

• Structural loading issues

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If cracking continues to develop, professional advice should be obtained.

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When Should You Arrange a Survey?

 

It is sensible to seek advice where:

• A crack has appeared suddenly

• A crack is becoming wider

• Several cracks have appeared

• Cracks are visible both internally and externally

• Doors or windows have started sticking

• Floors appear uneven

• Previous repairs have reopened

• Cracks are associated with an extension

• You are concerned about subsidence

• A surveyor has recommended further structural investigation

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If you are unsure, photographs can often help us determine what type of inspection is likely to be appropriate.

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Which Survey Do I Need?

 

The appropriate survey depends on the extent of the concern.

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Specific Issue Survey

 

If the problem relates to one particular crack or localised area of movement, our Specific Issue Survey may be appropriate.

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Typical examples include:

• One crack above a window

• Cracking to one wall

• Movement around a bay

• Cracking between an extension and the house

• A localised defect identified by another surveyor

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Specific Issue Surveys start from £695 + VAT.

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The inspection focuses on the particular area of concern and includes a written report with recommendations.