1. Residential Roof Types
Civil Engineering and Architecture
© 2010 Project Lead The Way, Inc.

2. Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Residential Roof Types
Roof Shapes
Roof Types
Roofs in Architecture
Roofing Materials
Roofs as Sustainable Space
Energy Star Roof Systems
Roof Trusses
Roof Rafters
Roof Pitch
Building Codes
Roof Pitch and Materials
Project Lead The Way, Inc.
Copyright 2010

3. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Roof Shapes
Roofs protect buildings and occupants from wind, rain, cold, sun, heat, dust, etc.
Roofs add to the visual appearance of a building.
Pitched roofs shed rainfall away from the structure. Low-slope roofs require installation of drains to remove rain and snow melt from the structure.
Roofs come in many shapes.
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Copyright 2010

4. Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Roof Types
Shed
Gable
Hip
Gable with Dormer
Gable & Valley
Hip & Valley
Low-Slope
(Flat)
Gambrel
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5. Roofs as Sustainable Space
Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Roofs as Sustainable Space
Natural light creates a pleasant space for occupants and requires less energy for lighting.
Fewer light fixtures are required when using the light from the sun. One way to provide more natural light is by using skylights.
Architects can receive Leadership in Energy and Environmental Design (LEED) credits when reducing energy used by buildings.
Istockphoto.com®
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6. Energy Star Roof Systems
Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Energy Star Roof Systems
Energy collected from the sun can be used in the structure.
Reflective roofs reduce cooling energy costs.
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Copyright 2010

7. Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Roof Trusses
Courtesy Isle of Palms, SC Recreation Department
A roof truss is a simple assembly of members forming a rigid framework of triangular shapes.
Courtesy Leslie Eaves
Project Lead The Way, Inc.
Copyright 2010

8. Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Rafters
Rafters are an alternative to trusses for roof support.
Rafters are roof beams that slope from the ridge beam to the top of the wall.
Istockphoto.com®
Project Lead The Way, Inc.
Copyright 2010

9. Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Roof Pitch (Slope)
Roof pitch determined by rise/run
Run 12 in.
Rise 7 in.
Example:
A 7/12 (or 7:12) (pronounced “seven twelve”) pitch means that the roof rises 7 in. for every 12 in. horizontally.
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Copyright 2010

10. Common Residential Roof Covering Materials
Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Common Residential Roof Covering Materials
Standing Metal Seam
Clay/Cement Tiles
Asphalt Shingles
These roof covering materials are common for pitched (or sloped roofs).
Istockphoto.com®
Wood/Cedar
Slate
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11. Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Building Codes
A set of rules that specify the minimum standards for construction
International Residential Code (IRC)
Minimum regulations for residential building systems
Adopted by many municipalities
Dictates minimum roof slope by finish material
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12. Roof Pitch and Covering Materials
Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Roof Pitch and Covering Materials
Asphalt shingles
Slope. Asphalt shingles shall be used only on roof slopes of two units vertical in 12 units horizontal (2:12) or greater. For roof slopes from 2:12 to 4:12, double underlayment application is required.
Clay and Concrete tile
Deck slope. Concrete and clay tile shall be used only on roof slopes of two and one-half units vertical in 12 units horizontal (2½ :12) or greater. For roof slopes from 2½ :12 to 4:12, double underlayment application is required.
The International Residential Code includes regulations related to a vast array of building planning, design, and construction topics including design load criteria, energy conservation, mechanical systems, plumbing and electrical design. The code regulations related to roof slope presented here are a very, very small part of the IRC. We will discuss more IRC regulations later in this lesson.
Source: International Residential Code – Chapter 9 Roof Assemblies
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Copyright 2010

13. Roof Pitch and Covering Materials
Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Roof Pitch and Covering Materials
Slate and Slate-style shingles
Deck slope. Slate shingles shall be used only on slopes of four units vertical in 12 units horizontal (33- percent slope) or greater.
Wood Shakes
Deck slope. Wood shakes shall only be used on slopes of three units vertical in 12 units horizontal (25-percent slope) or greater.
Metal roof panels
Slope. Varies by type
Source: International Residential Code – Chapter 9 Roof Assemblies
Project Lead The Way, Inc.
Copyright 2010

14. Roof Pitch and Covering Materials
Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Roof Pitch and Covering Materials
Low-slope roofing materials
Built-up roofing
Modified bitumen roofing
Thermoset single-ply roofing
Thermoplastic single-ply roofing
Slope. Roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage.
Sloped roofs are designed with sufficient slope to ensure that rain water runs off of the roof fairly quickly. The shallower the pitch the longer the rain water remains on the roof. To protect the building against water intrusion, low slope roofs require covering materials that are more water-tight than is required for roofs with steeper slopes.
Source: International Residential Code – Chapter 9 Roof Assemblies
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Copyright 2010

15. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Identify the Roof Type
Low slope. Although it is not obvious in this picture, the roof covering must be of a material allowed for low-slope roofs such as a built-up roof, modified bitumen, or single-ply membrane.
Istockphoto.com®
Project Lead The Way, Inc.
Copyright 2010

16. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Identify the Roof Type
Shed. The roof covering is asphalt shingles.
Project Lead The Way, Inc.
Copyright 2010

17. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Identify the Roof Type
Gable with roof tiles.
Project Lead The Way, Inc.
Copyright 2010

18. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Identify the Roof Type
Hip roof (with valleys) with asphalt shingles.
Project Lead The Way, Inc.
Copyright 2010

19. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Identify the Roof Type
Gable and valleys with dormers. Wood shakes are used in this application.
Project Lead The Way, Inc.
Copyright 2010

20. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Identify the Roof Type
Gambrel.
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Copyright 2010

21. Residential Roof Types
Civil Engineering and Architecture®
Unit 2 – Lesson 2.1 – Building Design and Construction
Identify the Roof Type
Hip and gable, with valleys. The roof is covered with metal panel roofing.
Project Lead The Way, Inc.
Copyright 2010

22. Residential Roof Types
Civil Engineering and Architecture
Unit 2 – Lesson 2.1 – Building Design and Construction
Image Resources
iStockphoto. Retrieved March 16,2010 from
Microsoft, Inc. (n.d.). Clip art. Retrieved May 26, 2009, from
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