Common Structural Defects in Houses
Most homes show some movement over time. The key is telling harmless cracks from structural problems.
Warning Signs to Look For
| Sign | Possible cause |
|---|---|
| Diagonal or stepped cracks wider than ~3mm | Subsidence, foundation movement |
| Cracks that reopen after filling | Ongoing movement |
| Doors and windows sticking | Frame distortion from movement |
| Bowing or leaning walls | Failed wall ties, lateral loads |
| Sagging floors or ceilings | Overloaded or rotted joists |
| Cracks above openings | Failed or undersized lintel |
| Gaps between extension and house | Differential settlement |
Typical Causes
- Subsidence — clay shrinkage from trees or dry weather, leaking drains
- Heave — clay swelling after tree removal
- Poor alterations — walls removed without proper steel
- Corroded steel lintels — rust expansion cracks brickwork
- Roof spread — inadequate ties or removed supports
- Water damage — rotted timber, washed-out mortar
What a Structural Engineer Does
- Inspects and records the defects
- Identifies the cause (and checks drains, trees, history)
- Advises on monitoring if movement may be seasonal
- Designs the structural repair or strengthening
- Supports Building Control and insurer submissions
Typical Repairs
- Drain repair and tree management
- Underpinning or other foundation work
- Replacement lintels and steel beams — see lintel calculations
- Wall tie replacement or wall rebuilding
- Joist strengthening or replacement
Next Steps
- Structural Surveys →
- Subsidence Surveys →
- Cracks and subsidence guide →
- Structural engineer report guide →
📞 Call 07401 650600 or email us with photos of the problem — serving Ilford, Redbridge, Newham, East London, Tilbury, Grays and Thurrock.
