1. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. S TEEP R OOFS 16 R OOFING

2. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Shingles Small, overlapping roofing units with staggered vertical joints made of wood, asphalt, slate, clay, concrete, metal, or other materials S TEEP R OOFS

3. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Wood Shingles and Shakes Most commonly used woods are naturally decay-resistant species like red cedar, white cedar, and redwood. Wood Shingles: Tapered; both the face and back are sawn –Lengths: 16, 18, and 24 in. –Thickness: ¼ to ½ in. at the butt (thicker end) S TEEP R OOFS

4. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Wood Shingles and Shakes Wood Shakes: Thicker than shingles, usually split on one or both faces –May be tapered or uniform thickness ("straight") –Length: 18 and 24 in. –Butt thickness ½ to ¾ in. A split face has a rougher texture than a sawn face. Shakes generally produce a rougher textured surface with stronger shadow lines than shingles. S TEEP R OOFS

5. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Wood Shingles and Shakes To improve longevity and where practical, wood shingles and shakes should be installed with air circulation beneath. Skip sheathing: Spaced sheathing boards (right) allow air circulation under shingle or shakes. S TEEP R OOFS

6. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Wood Shingles and Shakes Solid sheathing, usually plywood, is recommended for areas prone to wind- driven snow or ice damming. (See eave in adjacent image and in previous photo.) Solid sheathing may also be required for roof decks in areas of high seismic risk. S TEEP R OOFS Roofing paper underlayment is used under shingles and shakes over solid sheathing, and may be woven into shakes (but not shingles) over skip sheathing.

7. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Wood Shingles and Shakes Breather mat: Roughly 3/8-in. thick mat of tangled synthetic fibers installed over solid sheathing and roofing felt, to allow air to circulate under the shingles or shakes S TEEP R OOFS

8. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Wood Shingles and Shakes Prone to decay and surface erosion of the wood fibers (right) Can be preservative-treated for improved decay-resistance Vulnerable to fire, but can be chemically treated to reduce flammability S TEEP R OOFS

9. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Wood Shingles and Shakes Unique, natural appearance Minimum slopes: –Shakes: 4:12 –Shingles: 3:12 Life expectancy: 15 to 25 years S TEEP R OOFS

10. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Asphalt or Composition Shingles Cut from heavy, asphalt- impregnated fiberglass or cellulosic felts Surface mineral granules provide color, and protect the shingles from UV degradation and abrasion. The standard 3-tab shingle is 12" wide x 36" long. S TEEP R OOFS

11. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Asphalt or Composition Shingles Available in a variety of styles, weights, and colors S TEEP R OOFS

12. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Asphalt or Composition Shingles Installed over solid sheathing and underlayment of asphalt-saturated felts or synthetic membranes S TEEP R OOFS

13. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Asphalt or Composition Shingles Roofing underlayment and shingles (of all types) are generally installed starting from the eaves and working up the slope of the roof, to achieve an overlapping that naturally sheds water off the roof. Metal flashings at roof edges protect against water seepage under the shingles. S TEEP R OOFS

14. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Asphalt or Composition Shingles Flexible and easily cut The open valley requires additional sheet metal work. Woven and closed cut valleys can be completed without sheet metal. S TEEP R OOFS

15. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Asphalt or Composition Shingles Moderately fire- resistant Life expectancy: 15 to 25 years Minimum slopes: –4:12 –2:12 with double- coverage roofing paper underlayment S TEEP R OOFS

16. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Mineral Surfaced Roll Roofing Same material as asphalt shingles, supplied in 3-ft wide rolls. Fastened with nails at overlapping edges. May also be set in asphalt adhesive. Minimum slope: 1:12 Life expectancy: 6 to 15 years S TEEP R OOFS

17. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Slate Shingles Split from natural slate, cut to size, and punched or drilled for nailing Minimum slope: 4:12 Heavy, noncombustible Durable, lasting up to 60-80 years Note the copper flashing and synthetic underlayment material (to the left in the photo) S TEEP R OOFS

18. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Clay and Concrete Tile Kiln-dried clay or cast concrete Glazed or unglazed Heavy, noncombustible Minimum slopes: –4:12 –2½:12 with double- coverage underlayment Life expectancy: 30 to 75 years S TEEP R OOFS

19. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Other Shingle Materials Sheet metal Rubber Fiber-reinforced cement Plastic Top: Aluminum roofing shingles, stamped and coated to imitate the appearance of slate. Bottom: Copper roofing shingles S TEEP R OOFS

20. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Architectural Sheet Metal Roofing Roofing made from a variety of metals in sheet form More expensive metals form self-protecting oxide coatings: –Lead –Copper –Zinc –Stainless steel These metals naturally patina to variety of shades and colors depending on the metal itself and the atmospheric conditions under which they are placed into service. Right: Copper sheet metal patinas to colors ranging from green to black, depending on atmospheric conditions. S TEEP R OOFS

21. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Architectural Sheet Metal Roofing Less expensive, less long-lasting metals are usually coated with high-performance paint-like coatings for greater protection: –Aluminum –Metallic-coated steel (zinc- or zinc- aluminum-coated steel) –Ferrous (plain) steel Right: Coated aluminum sheet metal roofing S TEEP R OOFS

22. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Metallic-Coated Steel Steel with a thin coating of zinc or zinc-aluminum alloy These coatings extend the life of the metal by: –Forming self-protecting oxide coatings (unlike steel which readily corrodes) –Providing galvanic protection, sacrificing themselves to protect the underlying metal if the coating is scratched and the underlying metal is exposed S TEEP R OOFS Zinc-coated (galvanized) steel sheet metal

23. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Flat-Seam Metal Roofing Typical pan size: 18 in. x 24 in. Attachment cleats are nailed to decking and rolled into the flat pan seams. For slopes below 4:12, seams are soldered for greater watertightness. For steeper slopes, seams may be sealed with mastic or elastomeric sealant. Rosin paper applied over the asphalt-saturated roofing paper prevents panels from wearing through the underlayment as they expand and contract with temperature changes. S TEEP R OOFS

24. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Flat-Seam Metal Roofing Right: Soldering flat metal roofing seams on a low-slope roof S TEEP R OOFS

25. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Standing-Seam Metal Roofing Typical pan width: 18 – 24 in. Seams are typically ¾- to 1-in. tall. Cleats are nailed to decking and rolled into the seams. For slopes below 4:12, seams are sealed and rubberized roof underlayments with greater resistance to water passage are used in place of traditional roofing paper underlayment. S TEEP R OOFS

26. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Standing-Seam Metal Roofing Right: Standing seam copper roofing S TEEP R OOFS

27. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Batten-Seam Metal Roofing Typical pan width: 20 – 24 in. Seams are typically 2-in. tall. Cleats are nailed to decking and rolled into the seams. For slopes below 4:12, seams are sealed and rubberized roof underlayments with greater resistance to water passage are used in place of traditional roofing paper underlayment. The slight tapering in the battens (right) allows for unrestrained expansion and contraction of the sheet metal. S TEEP R OOFS

28. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Batten-Seam Metal Roofing Right: Batten-seam copper roofing S TEEP R OOFS

29. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Architectural Sheet Metal Roofing Sheet metal roofing panels are produced in one of two ways: in a factory or on the construction site. Specification terminology: –Factory-formed panels: Metal Roof Panels –Site-formed panels: Sheet Metal Roofing Right: Metal roof panels. Coated steel, factory- formed standing seam panels S TEEP R OOFS

30. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Architectural Sheet Metal Roofing Right: Sheet metal roofing. Sheet copper coming off a coil (toward the top- right of the photo) is rolled into a standing seam pan on the construction site using a portable panforming machine. S TEEP R OOFS

31. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Sheet Metal Thickness Steel sheet thickness historically expressed in gauge numbers Note: Higher gauge numbers correspond to thinner sheets! Contemporary standards refer to steel sheet metal thickness in decimal inches. Gauge numbers are still frequently used in common practice. S TEEP R OOFS

32. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Sheet Metal Thickness Copper sheet thickness is expressed as the weight in ounces of one square foot of metal. Aluminum sheet thickness is expressed in decimal inches. S TEEP R OOFS

33. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Galvanic Series of Metals When different metals come into contact, electrical current flows between them, and corrosion of the more active or anodic metal results. Avoid direct contact between metals far apart on the galvanic series. The further apart the metals on the list, the greater the electrical potential difference and the greater the potential corrosion. For example, it is relatively safe to have copper and tin in direct contact; but contact between copper and zinc should be avoided (right). It is usually safe for fasteners to be more cathodic than the metals they attach. For example, stainless steel fasteners are OK for copper roofs; zinc coated fasteners are not. (See the text for a more in-depth discussion.) S TEEP R OOFS Greater potential difference Lesser potential difference

34. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. S USTAINABLE R OOFING 16 R OOFING

35. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Cool Roofs Roofs meeting the minimum reflectance requirements of one or more green rating systems Roofs with high solar reflectance or solar reflective index (SRI) experience lower temperatures. Reducing solar heating of roofs reduces cooling loads on the building, increases the life of roofing materials, and reduces urban heat island effects. S USTAINABLE R OOFING

36. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Cool Roofs White or light-colored single-ply membranes Modified bitumen low-slope roof membranes surfaced with reflective-white coated granules White liquid-applied membrane coatings(top) Composition shingles surfaced with cool color coated granules meeting cool roof requirements (bottom) S USTAINABLE R OOFING

37. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Cool Roofs Sheet Metal Roofs: All of the colors on the metal roof panel color chart at right are cool colors meeting cool roof requirements for steep roofs. Cool colors meet cool roof requirements by selectively reflecting solar energy in the near- infrared portion of the spectrum while absorbing light in the visible spectrum (which accounts for their apparent color). S USTAINABLE R OOFING

38. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Green Roofs Roofing systems covered with vegetation; also called eco roofs or vegetated roofs Protect roof membrane from UV degradation and temperature extremes Moderate swings in building heating and cooling loads Reduce noise transmission and reflectance Reduce stormwater runoff Provide natural habitat Reduce urban heat island effects S USTAINABLE R OOFING

39. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Green Roofs Extensive green roofs –2-4 in. soil depth –Low-maintenance, drought- tolerant plants –Moderate roof loads Intensive green roofs –Up to 36 in. or more in soil depth –Greater variety of plants, shrubs, and even trees –Irrigation and plant maintenance required –Greater roof loads Right: An extensive green roof during installation –Note the gravel borders that confine plant growth away from parapets and walls. S USTAINABLE R OOFING

40. Fundamentals of Building Construction, Materials & Methods, 5 th Edition Copyright © 2009 J. Iano. All rights reserved. Green Roofs Typical components include –Plant materials –Growth medium (soil and amendments) –Filter fabric, to confine soil particles –Drainage/aeration/water storage layers –Rigid insulation –Protection layer/root barrier –Roofing or waterproofing membrane (may be located above or below the insulation) –As needed: air barrier, vapor retarder, and/or substrate board –Roof deck S USTAINABLE R OOFING Simple, light weight extensive green roofs may rely on conventional roofing membranes for waterproofing. Heavier, intensive systems more commonly rely on more robust waterproofing membranes intended for below-grade applications.