Cracking & Movement

 

Introduction

Cracking and movement in the walls of houses, or other low-rise masonry buildings, can, at first sight, appear quite alarming. As properties throughout the UK have soared in value and as people have stretched themselves to the limit to pay mortgages so has their tolerance to apparent structural defects diminished. Even minor cracking is regarded with horror - it's therefore hardly surprising that insurance claims have risen dramatically over the last 20 years or so. This increase in claims has sometimes resulted in unnecessary or inappropriate remedial work. Repairs carried out without determining the exact cause of the problem can do more harm than good. This section of the web site provides an introduction to the causes of cracking in external walls - it's divided into four sections:
  • substructure - problems caused by poor foundations or more deep seated problems in the ground beneath them.
  • superstructure - cracking and movement which are not related to the above.
  • diagnosis - an introduction to recording, monitoring and diagnosing substructure and superstructure problems.
  • a short section on foundation repairs and remedial work.

There are plenty of books on this subject. It's not normally our job to recommend any - although a good starting point is BRE (and we have included a few in the Diagnosis section). BRE produce a variety of books and articles on cracking and movement. Some are very technical but many are easy to read, well set out and a very good starting point. Do not regard anything you read in this section as a substitute for professional advice - its purpose is to provide you with a starting point in the development of your knowledge and understanding of cracking and movement, and to encourage you to think about all the options, including the need for professional advice, before arriving at a diagnosis. 

Although cracking is associated with structural movement it should be remembered that there are other possible consequences. These include:

  • the risk of increase sound transfer if cracks are in party walls
  • cracks will encourage damp penetration and possible saturation dependent chemical attack, ie sulfate attack and wall tie failure.
  • cracks may tear vapour checks with a consequential increased risk of interstitial condensation
  • cracks in floor may allow radon or methane penetration
  • cracks in concrete housing may hasten carbonation and rusting

NB. The Defects Photos section shows a number of photos of cracking and movement - many of them sent it by former students. A few of them are also shown in this section.

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