Contents Preface xiii Acknowledgments xv Chapter 1. Introduction 1 Why Roofs Fail 2 Lessons from History 6 Need for Research and Standards 7 Chapter 2. The Roof as a System 9 Design Factors 9 Basic Roof Components 10 Disastrous Combinations 15 Constructing the Roof 16 Divided Responsibility 17 Unified Responsibility 17 Performance Criteria 18 References 24 Chapters. Draining the Roof 25 Why Drain the Roof? 28 Life-Cycle Costing Example 31 How to Drain the Roof 32 Drainage Design 34 Draining an Existing Roof 41 Alerts 42 Design 42 Maintenance 42 References 42 Chapter 4. Structural Deck 43 Deck Materials 43 Design Factors 46 Slope 46 Deflection 48 Dimensional Stability 49 Moisture Absorption 51 Anchorage of Components 51 Deck Surface and Joints 53 Steel Decks 54 Recommendations for Steel Decks 55 Alerts 56 Design 56 Field 57 References 58 Chapter 5. Thermal Design 59 Thermal Insulating Materials 60 Rigid Board Insulation . 61 Poured-in-Place Insulating Concrete Fill 63 Design Factors 64 Strength Requirements 66 Moisture Absorption 66 Venting 68 Dimensional Stability 69 Tapered Insulation 71 Anchoring Insulation to the Deck 71 Solid Bearing for Insulation Boards 72 Refrigerated Interiors 72 Effects of Increased Insulation Thickness 73 Joint Taping 74 Double-Layered Insulation 75 Principles of Thermal Insulation 77 Moisture Reduction of Insulating Value 78 Heat-Flow Calculation 80 Heat Gain or Loss 83 Cool Roofs 83 Principles of Radiant Heat Transfer 85 Complicating Factors 89 California Cool 91 Seasonal Factors 92 ANSI/IESNA 94 ASHRAE Standard 90.1 94 Alerts 96 Design 96 Field 97 References 99 Chapter 6. Vapor Control 101 Fundamentals of Vapor Flow 101 Techniques for Controlling Moisture 104 General Ventilation 105 Vapor Retarder 105 Self-Drying Roof System 113 The Futility of Topside Venting 117 Theory of Vapor Migration 117 Diffusion 117 Air Leakage 120 Air Barriers 122 Sample Vapor-Retarder Calculation 123 Alerts 126 Design 126 Field 127 References 127 Chapter 7. Wind Uplift 129 Historical Background 131 Mechanics of Wind-Uplift Pressure 135 Basic Wind-Speed Determinants 136 Building Shape, Size, and Enclosure 142 Determining Final Wind-Uplift Pressure 144 Procedure for Calculating Design Wind Pressure 149 Design Example: Anchored System 150 SEI/ASCE 7-02 versus FM Global 151 Perimeter Flashing Failures 152 Wind-Uplift Mechanics on Ballasted Roofs 155 Gravel Blowoff and Scour 158 Wind-Uplin Design for Ballasted, Single-Ply Roof Assemblies 160 Basic Ballasted Wind-Design Systems 163 PMR Wind Design 168 Retroactive Redesign 170 Design Example for Ballasted, Loose-Laid System 170 Wind-Uplin Testing 170 Laboratory Tests 171 Field Wind-UplittTests 175 Repair Procedures after Wind-Uplin Failure 176 Mechanical Fasteners177 Alerts 183 General 183 Design 183 Field 183 References 184 Chapter 8. Fire Resistance 185 Nature of Fire Hazards 185 External Fire Resistance 186 Internal Fire Hazards 188 Below-Deck Fire Tests and Standards 189 Flame-Spread Test 189 FM Fire Classification 189 Time-Temperature Ratings 191 Fire Rating versus Insulating Efficiency 192 Building Code Provisions 193 Alert 193 Chapter 9. Historical Background of Contemporary Roof Systems 195 Built-up Bituminous Membranes 196 The First-Generation Single-Ply Pioneers 197 The Cold-Process Dead End 198 The Second-Generation Success 198 New Roof Systems 200 Modified Bitumens 203 Chapter 10. Elements of Built-up Membranes 207 Membrane Materials 209 Roofing Bitumens 209 Incompatibility of Asphalt and Coal Tar Pitch 214 Coal Tar Pitch versus Asphalt 215 Felts 215 Surfacing 219 Smooth-Surfaced Membrane 225 Mineral-Surfaced Roll Roofing 226 Heat-Reflective Surfacings 226 Built-up Membrane Specifications 227 Shingling of Felts 227 Coated Base Sheet 229 Phased Application 230 Temporary Roofs 233 Joints in Built-up Membranes 234 Membrane Performance Standards 236 BUR Failure Modes 238 Blisters 239 Splitting 249 Ridging 254 Membrane Slippage256 Alerts 260 General 260 Design 261 Field 261 References ._ 263 Chapter 11. Modified-Bitumen Membranes 265 Historical Background 266 Modified-Bitumen Materials 268 Rubberizing Polymers 268 Reinforcement 269 Surfacing 274 Modified-Bitumen Specifications 275 Modified-Bitumen Flashings 278 Performance Criteria for Modified Bitumens 279 Modified-Bitumen Failure Modes 282 Defective Lap Seams 282 Checking 283 Shrinkage 285 Blistering 285 Delamination :- 288 Slippage 288 Splitting 290 Alerts 291 General , 291 Design 291 Field 291 References 292 Chapter 12. Elastomeric Membranes 293 Basic Material 293 Field Seaming296 Flashings 296 Mechanically Fastened Systems 301 Elastomeric Failure Modes 301 Alerts 305 General 305 Design 307 Field 307 References 307 Chapter 13. Weldable Thermoplastics 309 Materials309 Historical Background 312 Flashings 315 Failure Modes 315 Alerts 316 References 317 Chapter 14. Flashings 319 Flashing Functions and Requirements 320 Materials 321 Base Flashing Materials 322 Counter-flashing Materials 325 Principles of Flashing Design 326 Eliminating Penetrations 326 Reducing Openings 327 Flashing Elevation ! 327 Differential Movement 328 Flashing Contours and Cants 329 Flashing Connections 329 Specific Flashing Conditions 330 Edge Details 330 Vertical Flashings 331 Roof Penetrations 333 Expansion-Contraction Joints , , 338 Water Conductors 341 Flashing Failures 341 Sagging 341 Ponding Leakage 342 Diagonal Wrinkling 342 Poslconstruction Damage 344 Alerts 344 General 344 Design 344 Field 345 Standard Details 345 Chapter 15. Protected Membrane Roofs and Waterproofed Decks 367 Why the Protected Membrane Roof? 369 How PMR Changes Component Requirements 372 PMR Design and Construction 373 Drain Location 374 PMR Flashings ; 374 PMR Insulation Performance Requirements 374 Thermal Quality of PMR Insulation 377 Refinements in Locating PMR Insulation 377 Surfacing Protected Membrane Roofs 378 Life-Cycle Costing 379 Waterproofed Deck Systems 381 Structural Decks 381 Membranes382 Protection Boards 385 Drainage Design 385 Aggregate Percolation versus Open Subsurface Drainage 387 Insulation 387 Flashing 388 Wearing Surface Design 389 Plaza Furniture 390 Detailing390 Flood Testing 390 Alerts (for PMRs) }391 Alerts (for Waterproofed Decks) 391 Design 391 Field 392 References 393 Chapter 16. Sprayed Polyurethane r 395 Historical Background 396 Materials 399 Polyurethane Foam 399 Membrane Coating 401 Surfacing Aggregate 406 Detailing SPF Systems 407 Application Requirements 407 Foam Application 414 Coating Application 417 Quality Assurance 418 Maintenance 419 Alerts 480 General 420 Design 420 Application 420 Maintenance 420 References420 Chapter 17. Metal Roof Systems 423 Historical Background 424 Metal Roof Concepts and Terminology 427 Design Factors428 Thermal Movement 428 Drainage 429 Condensation 429 Penetrations 430 Wind-Uplift Resistance 430 Corrosion Protection 430 Metal Roofing Accessories 432 Thermal Insulation 437 Underlayments 438 Vapor Retarders 439 Detailing Metal Roofing 439 Metal-Roof-System Defects 442 Aesthetic Problems 442 Functional Problems 444 Metal Roof Evaluation 447 References 447 Chapter 18. Field Inspections . 449 Quality Assurance 449 QA Inspections J 450 Application Checklists 456 Visual Roof Surveys 463 Nondestructive Moisture Detection 465 Benefits of Nondestructive Moisture Detection 467 Limitations 468 Principles of Nondestructive Moisture Detection 468 Other Moisture-Detection Techniques 471 References 473 Chapter 19. Reroofing and Repair 475 Re-covering or Tearoff-Replacement? 477 Investigation and Analysis 478 Preliminary Investigation 478 Leak-Detection Technique 479 Visual Inspection and Analysis 479 Field-Test Cuts 481 Large-Scale Moisture Surveys .481 Assessment for Remedial Action 481 New Performance Criteria 482 Reroofing specifications 483 Isolating the New Membrane 484 Flashings 484 Surface Preparation of Existing Membrane485 Retrofit Metal Roofing 486 Alerts 487 For Replacement Bituminous Roof Membranes 487 For Loose-Laid Synthetic Single-Ply Membranes 490 For Sprayed Polyurethane Foam (Plus Fluid-Applied Coating) 490 Chapter 20. Roof-System Specifications 493 Specifications and Drawings 494 Drawing Requirements 494 Specification Requirements 494 Writing Style 495 Specifying Methods 495 Master Specification 496 Division of Responsibility 497 Temporary Roofing 498 Special Requirements 498 Specifying New Roofing Products 499 Quality Assurance 500 Coordination 501 Test Cuts 502 Alerts 504 General 504 New Products 504 General Field 504 Technical 505 References 505 Chapter 21. Roofing Guarantees and Warranties 507 Manufacturer's Bond 507 Manufacturer's Warranty 509 Analyzing the Warranty 510 Warranty Checklist 513 Roofer's Guarantee 514 Roof-Maintenance Program 515 Glossary of Roofing-Related Terms 517 Appendix A ASTM International Conversion Factors and Roofing Standards 547 Appendix B Index and Abstracts of ASTM Test Methods for Roofing Materials 551 Index 571