Roofing Design and Practice

by Patterson, Stephen; Mehta, Medan

• ISBN13: 9780130259950
• ISBN10: 0130259950
• Format: Hardcover
• Copyright: 2001-01-01
• Publisher: Pearson College Div

Summary

For courses in Construction Methods and Materials, Commercial Construction, Residential Construction, and Roofing Design, in departments of Architecture, Architectural Engineering, and Construction Science/Management/Technology.Combining academic rigor with contemporary design practice, this is the first true text book on roofing design, and the only reference that comprehensively addresses all roof design issues. It provides necessary information on the suitability of various systems for specific projects, and offers students a greater knowledge that will enable them to prevent most roof failures and resulting disputes.

Table of Contents

Introduction to Roofing	1	(12)
Roof Types Based on Roof Slope	2	(1)
Steep Roofs	3	(3)
Low-Slope Roofs	6	(4)
Other Roof Types	10	(1)
Roof Design Process	11	(2)
Built-Up Roof Membranes	13	(24)
Anatomy of a Built-Up Roof Membrane	14	(5)
Built-Up Roof Felts	19	(3)
Layout of Built-Up Roof Felts	22	(3)
Use Classification of Built-Up Roof Felts	25	(2)
Bitumen	27	(1)
Roofing Asphalt	28	(3)
Roofing Coal Tar	31	(1)
Surfacing on a Built-Up Roof	32	(5)
Modified Bitumen and Single-Ply Roof Membranes	37	(22)
Anatomy of a Modified Bitumen Sheet	38	(1)
SBS-Modified Bitumen Membrane	39	(4)
APP-Modified Bitumen Membrane	43	(3)
Single-Ply Roof	46	(4)
Attachment of a Single-Ply Membrane to Substrate	50	(7)
Roof Membrane Selection	57	(2)
Roof Insulation	59
Modes of Heat Transfer	61
Heat Transfer by Conduction	63
R-Value of a Multilayer Component	68
Heat Transfer by Convection and Radiation	69
U-Value and Minimum Required Roof Insulation	72
Other Important Properties of Roof Insulation	73
Rigid Board Roof Insulation Types	75
Primary and Secondary Roof Insulations	80
Insulating Concrete Fill	81
Protected Membrane Roof	85

Excerpts

PREFACE OBJECTIVES OF THIS BOOK The aesthetic aspects of a roof may or may not be important, but in functional performance, the roof is one of the most critical components of a building. Most energy loss from a building envelope (particularly from a single-story building) occurs through the roof. Disastrous wind -caused damage to a building initiates when the roof fails to function as a structural diaphragm. Inadequate roof drainage may cause excessive water ponding on the roof, leading to its collapse. Water leakage, the most aggravating aspect of the malperformance of a building envelope, occurs primarily through the roof. In fact, a large majority of owners' complaints with the design and construction of buildings relate to roofs that leak. Although authoritative data is not available, it is estimated that nearly 65% of building construction lawsuits relate, in one way or the other, to roofing problems. The above statistic assumes significance considering that the roof cover of a typical building is replaced every few years -- one estimate gives a 12- to 14-year period. This replacement frequency would be unacceptable for any other envelope component - walls, doors, windows, etc.! It is the authors' belief that most roof failures and the resulting disputes can be prevented if the architects, engineers, contractors, roofing consultants, and facility managers -- all personnel engaged in the design, construction, and maintenance of buildings -- have greater knowledge of roofing design and practice. This book has been written to supply that knowledge. It has taken several years to complete this book, during which the authors cotaught (and still continue to teach) a five-week component on roofing design to architecture students at the University of Texas at Arlington, as part of a building construction course. Roofing Design and Practiceis a joint undertaking of a roofing consultant, who has been in practice for over 25 years, and a university professor, who has taught building construction courses to architecture students for nearly the same period. Therefore, it combines academic rigor with the meticulousness necessary in contemporary design practice. It is expected that it will serve both as a text for students of architecture and construction, as well as a reference resource for roofing consultants, practicing architects, consulting engineers, construction specifiers, roofing contractors, and facility managers. The need to undertake this project arose from the relative absence of a suitable publication, which could be adopted as a textbook for the course. An initial survey by the authors indicated that, although there are a few excellent manuals and compendiums dealing with the subject, none address all of the design and practice issues comprehensively in the reader-friendly format of a textbook. Anyone involved with roofing design and installation knows that the roof in a contemporary building is an extremely complex component. Long gone are the days when a roof in architectural drawings could be represented by a squiggly line atop a wood or concrete deck, indicating a three- or four-ply, gravel-covered, built-up roof. In fact, it is highly inaccurate to refer to a contemporary roof as a mere component, since it consists of an integrated and interactive system of several components. A typical low-slope roof in today's building consists of a roof membrane, insulation, vapor retarder (and sometimes an air retarder), and a roof deck. All of these components must be physically and chemically compatible with each other. Each component has its own individual design requirements, in addition to those of the system as a whole. The roof must not only provide a waterproof cover over the building and be durable against all deteriorating environmental elements (such as ultraviolet radiation, exhausts from neighboring industries, kit