Roof Construction Details: Useful Information Guide

By Roof Online Staff • Updated March 21, 2024

Roof construction detail drawing that shows a pipe penetration flashing detail for a built-up roof.
Pipe penetration flashing detail for a built-up roof

Construction details are focused, precise drawings that provide guidance for the person who performs the actual installation of a building component or system. Details contain very specific information about the various aspects of a building project. They focus on particular locations and parts of a building, showing complex building elements and junctions that general drawings cannot fully convey. These details are usually drawn at a larger scale than the main project drawings, providing a close-up view of how different components of the structure fit together.

Details will typically specify the materials and products to be used, the sizes and dimensions of the products, and show how they are supposed to fit together in order to achieve the proper functionality and appearance of that particular part of the building.

These focused drawings are normally produced by a specifier who works for a manufacturer, architect, or construction consultant. Details may also be produced by a contractor and then submitted for approval by an architect or engineering firm who works for the building owner. Construction details are generally drawn using some sort of CAD (computer-aided design) program.

For roofing contractors, these drawings are especially important during the roof installation process for several reasons:

  1. Clarity on Materials: Details specify the materials to be used in the roofing process, including the type of roofing material (such as tiles, shingles, or metal panels), underlayment, flashing, and any special coatings or sealants. This ensures that the right materials are used at every stage of the installation, contributing to the roof’s durability and performance.
  2. Installation Techniques: These drawings outline the specific methods and techniques required for installing the roofing materials. This might include the pattern in which tiles or shingles should be laid, the method for installing underlayment, or the technique for sealing joints and edges.
  3. Waterproofing and Insulation: Roofing details provide instructions on how to achieve effective waterproofing and insulation. They show how to install vapor barriers, insulation layers, and waterproofing membranes, crucial for preventing water ingress and ensuring the building’s thermal efficiency.
  4. Detailing of Roof Components: Details will include critical information about the installation of specific roof components like vents, skylights, chimneys, and guttering. They show how these components are supposed to integrate with the roofing materials to prevent leaks.
  5. Complex Junctions: Roofing often involves complex junctions, such as where the roof meets walls, at hips and ridges, or around penetrations. The details provide clear guidance on how the installer is supposed to handle these junctions, ensuring they are properly constructed to prevent water from entering the building.
  6. Compliance and Standards: These drawings ensure that the roofing work complies with building codes, standards, and manufacturer guidelines. This is important for passing inspections and maintaining the validity of warranties on roofing materials.
  7. Coordination with Other Trades: Roofing contractors often need to coordinate their work with other trades, such as HVAC or electrical contractors who may need to install systems that penetrate the roof. Detailed drawings help ensure that all contractors are aware of each other’s requirements and work together effectively.

Basically, construction details serve as a roadmap for roofing contractors, providing them with the specific information needed to execute each part of the installation correctly and in compliance with all relevant regulations and standards.

This helps to produce a high-quality finished roof system and plays an important role in achieving the “design life” of the roof and enhancing the overall performance of the building. In our years of performing roof leak and roof failure investigations, we’ve seen quite a few critical installation errors that could have been prevented if the roofer had just taken a look at the construction details before starting the work.

Thru-wall scupper detail for a modified bitumen roof.

1. General: Various roof-related construction details can be found on the Thermal and Moisture Protection CAD Drawings page on the ARCAT website.

2. Asphalt Shingle Roof DetailsThis page leads to a comprehensive selection of asphalt shingle details. Available at the GAF website.  

3. Built-up Roof Details: A selection of general flashing details for built-up roofs is provided on the Fields Company website.

4. Cedar Shake and Shingle Roof Details: This New Roof Construction Manual contains a large number of construction details. Available on the website of the Cedar Shake & Shingle Bureau.

5. Cedar Shingle Roof Details: Also see “Technical Information > Installation” at the Waska website for basic details.

6. Copper Roof Details: This Architectural Details page provides access to a number of well-put-together details for copper roofs and the copper components of shingled roofs. On the website of the Copper Development Association.

7. DrainsRoof Drain Details: An extensive list of easy-to-view details is provided on the Hy-Tech Products website.

8. EIFS Details: Access EIFS details on the Senergy EIFS (BASF) website.   

9. EPDM Roof Details: An extensive list of easy-to-view EPDM details is provided on the GenFlex website.

10. Expansion Joints: Construction details for various types of expansion joints can be accessed from the specialty roofing products page on the Johns Manville website. Click on the product type, then click on “technical”, then click on “installation instructions”.

11. Expansion Joints: Some good construction details for roof-to-wall expansion joints are available on the Copper Development Association website.

12. Gutter Details: Once again, the Copper Development Association does a great job with construction details. Their Hung Gutters page is copper-specific, but worth taking a look at regardless. 

13. Masonry Details: The International Masonry Institute has a number of good-looking construction details available to view or download on their Masonry Detailing Series page. 

14. Modified Bitumen Roof DetailsModified bitumen roof details can be viewed on the Siplast website.

15. PVC Roof Details: Many high-quality PVC roof details can be accessed on the Johns Manville website.

16. Scuppers: Roof Scupper Details: Details for various types of roof scuppers are available on the Copper Development Association website. 

17. Tile Roof Details: These tile roof installation guides, available at the Tile Roofing Industry Alliance’s website, are loaded with construction details. Just click where it says “Download PDF”. It looks like they are charging for access, but those prices are only for ordering hard copies.

18. TPO Roof Details: A library of TPO roof details is available on the website of Holcim Elevate, formerly Firestone Building Products.