Candidate Number: 0112257L TABLE OF CONTENTS Introduction 3 Types and Methods of Measurement 5 What is the roof area? 8 Figure1, Sample Sketch 9 What is the length of ridge necessary for ridge shingle units? 10 What is the length of valley necessary for valley metal flashing? 10 What is the length of edge necessary for drip edge flashing? 10 Waste Factors, Chimneys, Pipe Jacks 10 Factors Affecting Pricing 12 Overview Regarding Mark-Up 13 Developing the Time and Material Estimate 15 Sample Estimate 17 How to Test the Bid 18 Glossary 19 Bibliography 21 Appendix A: Table to Converting Flat Area to Roof Area 22 Appendix B: Xactimate Unit Cost Estimate 23 2 Candidate Number: 0112257L INTRODUCTION The Construction Specification Institute (CSI) has published CSI Standards and Formats. The Master Format 2012 publication “is a master list of numbers and titles classified by work results or construction practices, used throughout the North American construction industry to organize project manuals, detailed cost information, and relate drawing notations to specifications”.1 The CSI has organized construction practices into a 6-digit, 50-division system. This Technical Paper addresses Composition Shingle Roofing and associated flashing. The pertinent Master Format cites are: 07 00 00.00 Thermal and Moisture Protection 07 01 00.00 Operation and Maintenance of Thermal and Moisture Protection 07 01 50.81 Roof Replacement 07 01 60.00 Maintenance of Flashing and Sheet Metal 07 06 60.00 Schedules for Flashing and Sheet Metal 07 31 10.00 Shingles and Shakes 07 31 13.00 Asphalt Shingles 07 31 13.13 Fiberglass-Reinforced Asphalt Shingles 07 72 26.00 Ridge Vents “The roof frame forms the base to which roofing materials are applied. Its function is to keep out the weather and to protect the occupants. It must also provide proper drainage of water and be strong enough to withstand high winds and, in cold climates, heavy snow loads. In addition, the roof must be pleasing to the eye and compliment the structure it adorns.”2 “The material that is applied to the surface of a roof to make it waterproof and tight against the weather is called roofing.”3 The overwhelming majority of roofing in residential construction is composition shingle roofing. “Flashing is necessary to protect and waterproof all joints and interior angles on the roof surface, such as the intersections of roof slopes, areas around chimneys and vent pipes 1 www.csinet.org, specifically http://www.csinet.org/Main-Menu-Category/CSI-Store/6/26e3aea3-927a-e111- aa1a-0019b9e160b2.html. 2 John Capotosto, Basic Carpentry (Virginia: Reston Publishing Company, Inc., 1975), pg. 173. 3 Paul I. Thomas, How to Estimate Building Losses and Construction Costs (New Jersey: Prentice-Hall, 4th Edition, 1983), pg. 263. 3 Candidate Number: 0112257L and wherever there is a projection through the roof surface…The flashing must carry water over the joint and not into it.”4 Composition shingles are nailed over an underlying base felt that has been directly nailed to the structure’s wood roof sheathing. In certain building code jurisdictions, a new layer of composition shingles can be installed directly over a single existing layer of composition shingles. Historically, composition shingles were manufactured with an asphalt base that was a petroleum byproduct. The asphalt was mixed with organic base materials such as rag, wood, and jute. Asphalt shingles and asphalt saturated felts are organic products. In the last quarter of the 20th century a fiberglass mat was substituted for the organic base materials. Manufacturers developed fiberglass shingles and associated fiberglass base felts. “This has resulted in a stronger shingle with considerably more asphalt for the same weight as the felt base shingle. Consequently the fiberglass shingle has better weather resistance and a longer life.”5 Fiberglass shingles and fiberglass base felts are inorganic products. As inorganic products the glass fiber base is noncombustible. Organizations that rate building materials, such as Underwriters Laboratory, classify fiberglass shingles and felts with a Class A label; organic based products are classified with a Class C label. This paper assumes the use of the more modern fiberglass shingles and base felts. Both asphalt base and fiberglass base shingles are manufactured in the conventional three-tab configuration and size. Both asphalt base and fiberglass base have accompanying hip and ridge units. The application or installation method, and hence the man-hours necessary for installation, are the same for both asphalt base and fiberglass base shingles and underlying felts. In order to estimate the cost of composition shingles, flashing and other necessary accessories the estimator must determine: The quantity of roof area to be roofed. The shape of the roof. The slope of the roof. The amount of labor required. The quantity of material and quality of composition roof shingle. 4 John Capotosto, Basic Carpentry (Virginia: Reston Publishing Company, Inc., 1975), pg. 212. 5 Paul I. Thomas, How to Estimate Building Losses and Construction Costs (New Jersey: Prentice-Hall, 4th Edition, 1983), pg. 292. 4 Candidate Number: 0112257L TYPES AND METHODS OF MEASUREMENT “The unit of measurement for roofing is the square, which is an area 10’ x 10’, or 100 square feet. The quantity of roofing material needed is obtained from the measured area of the roof surface.”6 Field measuring while on the roof is the best way to obtain the measured area of the roof surface. Whether the estimator can be on the roof to obtain field measurements depends on access, safety conditions, roof shape, etc. Conditions of access and safety are: Obtaining permission of the owner or manager to enter the property. In residential properties having a sufficiently long ladder to safely reach the roof. For single story residences, a standard extension ladder or a folding / collapsing ladder is sufficient. For two story and higher residences the estimator will often have to arrange to have a multi- story ladder onsite. In commercial properties either having the correct ladder or having access to the interior roof hatch. Weather conditions such as dew, rain, or snow will affect safety. The pitch or steepness of the roof will impact safety concerns while obtaining field measurements. Low pitch roofs such as 4 in 12 (4:12) or less are easier to maneuver on than steeper pitched roofs. When possible arrange for an additional person as a ground spotter while the estimator is on the roof. The most common geometric shapes of roof slope are either rectangle or triangle. An entire roof area is typically composed of multiple slopes. (Please also see Glossary.) “Gable Roof: this roof is pitched with two slopes meeting at the ridge. It is of simple design, economical to construct, and one of the most common roofs used in residential homes.”7 A simple gable roof is two rectangular slopes. A gable roof is sometimes combined with a shed roof to create a shed dormer which is often attached to the gable roof slope at the home’s rear elevation. 6 Paul I. Thomas, How to Estimate Building Losses and Construction Costs (New Jersey: Prentice-Hall, 4th Edition, 1983), pg. 266. 7 John Capotosto, Basic Carpentry (Virginia: Reston Publishing Company, Inc., 1975), pg. 175. 5 Candidate Number: 0112257L “Shed Roof: Also called a lean-to, it is pitched in a single plane [or a single slope]. It is supported by walls or posts which are higher on one side than the other.”8 “Hip Roof: It has four sloping sides which rise to meet at the ridge. The lower edges of this roof form an overhang on all four sides of the structure. The hip roof is used mostly on low silhouette ranch type homes.”9 When the plan of the structure is rectangular a simple hip roof is four slopes, two rectangular and two triangular. “When the plan of the structure is square, all four sides [roof slopes] meet at a center point and the [roof] ridge is eliminated. It is then called a pyramid roof."10 A pyramid roof is four triangular slopes. The area of a rectangle is length multiplied by width. The formula is A = L x W. The area of a triangle is one-half base multiplied by height. The formula is A = 1/2B x H. A total roof area is the sum of the area of the individual slopes. Example: Assume a simple wood framed gable roof where the obtained field measurements taken while on the roof are: 1. Length of Ridge, including overhangs, is 42’. 2. Length of Eave edge, including overhangs, is 42’. 3. Length of Rafter edge, including overhangs, is 11’7”. This is also known as “the slope length from the ridge down to the lower edge or eave line including the overhang.”11 4. The slope length or length of rafter edge multiplied by the horizontal length of roof or the length of ridge equals the area of that slope. As a simple gable roof, it has two rectangular slopes (e.g., front elevation and rear elevation) meeting at the ridge: 1. Front elevation slope area is: a. A = 42’ x 11’7” b. A = 42’ x 11.5833 8 John Capotosto, Basic Carpentry (Virginia: Reston Publishing Company, Inc., 1975), pg. 174. 9 John Capotosto, Basic Carpentry (Virginia: Reston Publishing Company, Inc., 1975), pg. 175. 10 John Capotosto, Basic Carpentry (Virginia: Reston Publishing Company, Inc., 1975), pg. 175. 11 Paul I. Thomas, How to Estimate Building Losses and Construction Costs (New Jersey: Prentice-Hall, 4th Edition, 1983), pg. 269. 6 Candidate Number: 0112257L c. A = 486.5 SF 2. Rear elevation slope area is: a. A = 42’ x 11’7” b. A = 42’ x 11.5833 c.