New Build Cracks: Settlement or Something to Worry About?

Cracks in a new build do not automatically mean there is a structural problem. New homes contain plaster, mortar, concrete and timber that dry and respond to changes in temperature and moisture after construction.

NHBC says most homes experience some cracking at some point and that many cracks are not serious.

That reassurance should not be used to dismiss every crack as "settlement". The useful approach is to understand the likely causes, photograph what you see and look for signs that movement is continuing or affecting other parts of the home.

Why do cracks appear in new builds?

Common causes include:

• drying shrinkage

• thermal movement

• moisture changes

• movement where different materials meet

• ground settlement

Different causes can create similar-looking cracks, so appearance alone may not provide a definite diagnosis.

What are shrinkage cracks?

Many construction materials contain water when installed.

As plaster, mortar and concrete dry, they can shrink slightly. This can lead to fine cracks during the first months of occupation.

NHBC guidance says typical shrinkage cracks in masonry walls are often vertical or horizontal, a constant width and normally less than 2mm wide.

You may see them:

• near ceilings

• close to floors

• where plasterboard joints meet

• around skirting or architraves

• where different materials meet

Small cracks of this type are often cosmetic.

What is thermal movement?

Buildings expand and contract as temperature and moisture conditions change.

Different materials move by different amounts.

NHBC notes that thermal movement can create minor cracking around areas such as:

• junctions between external and internal walls

• plasterboard joints

• lintels

• timber joinery

• skirting and architraves

These cracks can appear or change slightly with the seasons.

Is it really "settlement"?

The word settlement is often used loosely.

Ground settlement can occur, but not every new build crack is caused by the foundations moving.

Drying shrinkage and thermal movement are common alternative explanations.

Avoid accepting or repeating a diagnosis unless someone appropriately qualified has actually assessed the issue.

When is a crack more concerning?

A crack deserves closer attention when the pattern suggests continuing or significant movement.

Examples include:

• cracking that noticeably widens

• stepped cracks through brickwork or blockwork

• repeated cracking after repair

• several related cracks appearing together

• distortion around windows or doors

• doors suddenly becoming difficult to close

• floors becoming noticeably uneven

• walls appearing to bow

• cracking accompanied by water ingress

• cracking that appears rapidly

These signs do not prove structural failure. They are reasons to obtain professional advice.

Does crack width matter?

It can be useful evidence, but width should not be treated as a diagnosis.

NHBC's homeowner guidance says shrinkage cracks are normally less than 2mm wide.

A wider crack is not automatically dangerous, and a narrow crack is not automatically irrelevant.

Location, direction, progression and associated symptoms also matter.

How should you monitor a crack?

Take clear photographs.

Include:

• the date

• the full wall or area

• a close-up

• a ruler or scale where practical

• notes about nearby doors, windows or floors

Repeat the photographs if you think the crack is changing.

Avoid relying on memory.

If the crack has already been repaired once, keep a record of the previous repair and when it reopened.

Should you fill cracks immediately?

For minor drying cracks, developers may advise waiting until the home has gone through more of its drying-out period before final decorative repairs.

However, do not simply fill and paint over a crack you believe is growing or linked to another problem.

Report it first.

Repairing the surface can hide useful evidence about whether movement is continuing.

What if cracks appear around doors and windows?

Small cracks can occur where different materials meet or around lintels as the home dries.

Look for the wider pattern.

Ask whether:

• the door or window still opens normally

• the frame looks distorted

• the crack is stable

• the crack is repeated on the exterior

• there is water ingress

• other nearby cracks are developing

If several symptoms appear together, professional assessment becomes more important.

Are ceiling cracks normal?

Hairline cracking can occur along plasterboard joints or where materials meet.

Report:

• cracks that are widening

• substantial sagging

• repeated cracking after repair

• cracking associated with water staining

• cracking accompanied by unusual movement

Water staining may indicate a leak rather than normal drying.

What should you report to the developer?

Report the crack with photographs and enough detail to locate it.

Include:

• room

• wall or ceiling

• approximate length

• approximate width

• date first noticed

• whether it is changing

• related symptoms

Ask the developer whether it intends to inspect, monitor or repair it.

What if the developer says it is normal?

Ask for the explanation in writing.

For a small stable drying crack, that may be reasonable.

If the crack is continuing to change or you remain concerned, consider an independent assessment.

A general snagging inspector may be able to document the defect, but suspected structural movement may need a suitably qualified building surveyor, structural engineer or other specialist.

Find local inspection firms through the snagging company directory, and ask about their scope before booking.

Does the warranty cover cracks?

It depends on the crack, age of the home, cause and policy terms.

A fine cosmetic shrinkage crack may not be an insured structural defect.

More significant damage caused by a qualifying defect may fall within warranty protection, depending on the policy.

Read the new build warranty guide and check the actual warranty issued for your property.

How does cracking fit into snagging?

Cracking is one item within a wider build-quality inspection.

Our common new build snag checklist covers finishes, windows, doors, drainage and other areas.

If you are deciding whether to commission an inspection, read is a snagging survey worth it?.

What if the developer will not investigate?

Keep your photographs and written timeline.

Use the formal after-sales process and escalate if necessary.

For Code-covered homes, developers must provide after-sales support and complaints procedures.

Read what happens if a developer won't fix snags.

Research the housebuilder before reserving

Look at recent customer feedback for recurring themes around cracking, remedial work and aftercare, but do not assume a review proves the cause of a technical defect.

Use the developer directory and developer rankings as part of wider research.

The bottom line

Fine cracks can be a normal part of a new home's drying and adjustment.

What matters is whether the crack is stable, where it appears and whether it is accompanied by other signs of movement.

Photograph cracks, monitor changes and report them. If cracking widens, recurs, distorts openings or appears with other significant symptoms, get appropriate professional advice rather than relying on the label "normal settlement".