Practical Guide to Diagnosing Structural Movement in Buildings

Concise and readable practitioner focused guide to diagnosing the causes of cracks and movement in buildings

The expanded and updated Second Edition of Practical Guide to Diagnosing Structural Movement in Buildings shows how movement can manifest as cracking in the building fabric and provides a rigorous, structured approach to understanding the evidence to ensure the surveyor can confidently diagnose the cause and impact of any structural movement they encounter.

The book is written in four parts, with part one describing the key principles of movement and cracking. Parts two and three describe the main features of common forms of movement and the associated crack patterns, with part two covering causes other than ground or foundation movement and part three covering movement caused by ground or foundations. Part four briefly describes the techniques used to arrest further movement or repair damage caused by movement.

Topics covered in Practical Guide to Diagnosing Structural Movement in Buildings include:

• First principles, including crack patterns and cracks, rotational movement, weak routes, load distribution, and movement and orientation
• Expansion cracking, cavity wall tie corrosion, roof spread, springing from deflected beams, and overloaded floors and beams
• Clay heave, uneven loading, eccentric loading on foundations, drains and drain trenches, differential foundation movement, and load concentrations on foundations
• Repair methods, including stitching in brickwork, reinforcing brick mortar joints, tie bars, restraint straps, underpinning, grouting, and root barriers

Primarily intended for the relatively inexperienced surveyor or engineer, as well as undergraduate students, Practical Guide to Diagnosing Structural Movement in Buildings focuses on identification and diagnosis, helping to correctly diagnose problems while also demonstrating a methodical approach to show and record how the diagnosis was reached, which is critical in client satisfaction.

Malcolm Holland, BSc(Hons) MRICS, started his career as a land surveyor in the Royal Engineers before leaving the Army to return to higher education. He gained a degree in Building Surveying and then qualified as a Chartered Surveyor in 1988. During the mid 1990s he spent four years as a senior lecturer at DeMontfort University teaching building construction and pathology to general practice surveying students. Since then he has worked predominantly in private practice and mostly in the field of residential surveying.

Introduction ix

List of Figures xii

Acknowledgements xix

Part 1 First Principles 1

1.1 First Principles 3

1.2 Crack Patterns and Cracks 8

1.3 Rotational Movement 9

1.4 Contra Rotational Movement 11

1.5 Weak Routes 14

1.6 Load Distribution 22

1.7 Movement and Orientation 26

1.8 Summary of First Principles and Process 28

Part 2 Cracks in Buildings Not Related to Foundations 31

2.1 Expansion Cracking 33

2.2 Cavity Wall Tie Corrosion 44

2.3 Corrosion of Metal Built into Walls 53

2.4 Vibration of Built-in Fixings 57

2.5 Roof Spread 60

2.6 Springing from Deflected Beams 67

2.7 Lack of Lateral Stability 70

2.8 Lack of Lateral Stability in Modern Gable Walls 76

2.9 False Chimneys, Lateral Instability and Movement in Gable Walls 79

2.10 Overloaded Beams 86

2.11 Absence of Lintels (Beams) Over Openings in Cavity Walls 91

2.12 Overloaded Floors 98

2.13 Overloaded Walls 102

2.14 Differential Movement 106

2.15 Arch Thrust and Arch Flattening 108

2.16 Arch Spread in Chimneys Built over Alleys in Terrace Housing 113

2.17 Buckling of Jambs to Sash Windows and Arch Flattening 118

2.18 Wall Shortening and Sequential Movement in Walls and Roofs (Holland’s Multiple Factor Diagnosis) 123

2.19 Load Path Cracking 135

2.20 Bulging of Walls Due to Decay of Bonding Timbers 138

2.21 Bulging and Separation in Solid Brick Walls 141

2.22 Separation of Rubble-Filled Stone Walls 144

2.23 Floor Slab Settlement (Compaction) 146

2.24 Load Concentrations 153

2.25 Sulphate Attack 155

2.26 Concrete Block Shrinkage 161

2.27 Shrinkage of Calcium Silicate Bricks 165

2.28 Heat Expansion of Flue Blocks 168

2.29 Floor Cracking in Suspended Concrete Beam and Block Floors 172

2.30 Vehicular Impact Damage (Usually Garages) 177

Part 3 Cracks in Buildings Related to the Foundations and Ground Movement 183

3.1 Introduction 185

3.1.1 Design for Load 187

3.1.2 Design for Stability 189

3.1.3 Identifying Below Ground Defects 190

3.2 Foundation Movement Caused by Clay Shrinkage 193

3.3 Clay Heave 201

3.4 Seasonal Expansion of Clay Subsoil 204

3.5 Eccentric Loading on Foundations 206

3.6 Uneven Loading 209

3.7 Load Concentrations on Foundations 211

3.8 Differential Foundation Movement 213

3.9 Initial Settlement after Construction or Alterations 218

3.10 Differential Foundation Settlement Cracking between Chimneys and Party Walls, in Alleys Running through Terraces 221

3.11 Leaking Drains and Water Discharge near to Buildings 225

3.12 Drains and Drain Trenches 228

3.13 Cracking Associated with Raft Foundations 231

Part 4 Repair Methods 241

4.1 Introduction 243

4.2 Re-pointing 245

4.3 Re-pointing with Epoxy Mortar 247

4.4 Stitching in Brickwork 248

4.5 Reinforcing Brick Mortar Joints 249

4.6 Tie Bars 251

4.7 Restraint Straps 254

4.8 Buttresses/Piers 256

4.9 Preventing Roof Spread 257

4.10 Underpinning 259

4.11 Expanding Foam Underpinning 263

4.12 Grouting 265

4.13 Root Barriers 267

Index 269

The New copy of this book will include any supplemental materials advertised. Please check the title of the book to determine if it should include any access cards, study guides, lab manuals, CDs, etc.

The Used, Rental and eBook copies of this book are not guaranteed to include any supplemental materials. Typically, only the book itself is included. This is true even if the title states it includes any access cards, study guides, lab manuals, CDs, etc.