Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D6369-99 – Standard Test Method Technical Guide
📐 Scope and Significance of EPDM Flashing Design
This guide covers the design of details for typical conditions encountered in new ballasted, mechanically attached, or fully adhered ethylene propylene diene terpolymer (EPDM) sheet roof systems. It assists designers in preparing details for each specific condition that may occur on a project. The values stated in SI units are to be regarded as standard, with conventional units provided for information purposes only. This standard does not address all safety concerns, so users must establish appropriate safety and health practices and determine regulatory limitations prior to use.
⚙️ Key Terminology and System Types
For definitions of terms used in this guide, see Terminology D1079. The following system types are defined based on membrane attachment method:
| 🟦 System Type | 📏 Description |
|---|---|
| Ballasted Sheet Roofing | A system which incorporates a loose laid vulcanized EPDM sheet over an accepted substrate and is held in place with either stone ballast, pavers, or a combination thereof. |
| Fully Adhered Sheet Roofing | A system which incorporates a vulcanized EPDM sheet fully adhered over a secured and accepted substrate. |
| Mechanically Attached Sheet Roofing | A system which incorporates a mechanically fastened vulcanized EPDM sheet over a secured and accepted substrate. |
📊 Design Guidelines for Drawings and Penetrations
The designer must detail all typical and special conditions on the project, with particular attention to transitions in plane and intersection of different details. Treated wood blocking shall be installed to provide attachment for accessory items such as gravel stops and metal sleeves. For penetrations, flashing must accommodate differential movement between the deck and penetration (e.g., pipe, conduit, column, or drain). Where “H” or “I” column sections occur, install blocking between flanges to facilitate flashing installation and weld sloping steel hoods to the column.
| 📐 Flashing Detail | 🎯 Requirement |
|---|---|
| Hood vertical leg extension | Minimum 100 mm (4 in.) over flashing |
| Treated wood blocking | For attaching accessory items (e.g., gravel stops, metal sleeves) |
| Penetration flashing | Accommodate differential movement between deck and penetration |
This guide does not address all installation requirements such as membrane cleaning, surface preparation, fastener spacing, or adhesive application. Insulation, fastener types, protection mats, stone ballast, pavers, and perimeter attachment requirements are also not covered. The designer shall review project requirements and consult the membrane system supplier, building insurer, and local building codes for specific needs.
⚠️ Important: This guide is not all-inclusive. The designer must detail all typical and special conditions, with particular attention to transitions and intersections. Shop drawings should be provided to confirm field conditions and design intent.
💡 Tip: The membrane system supplier or system applicator should provide shop drawings of each condition to verify field conditions and confirm understanding of the design intent.
❓ Frequently Asked Questions
🔍 What is the minimum extension for vertical hood legs over flashing?
Per Section 6.1.1, the vertical leg of the hood must extend a minimum of 100 mm (4 in.) over the flashing to ensure proper coverage and drainage.
💡 Which components are not covered by this guide?
Insulation, fastener types, protection mats, stone ballast, pavers, and perimeter attachment requirements are not covered. These must be determined from project specifications and supplier consultations.
⚡ Why is treated wood blocking required?
Treated wood blocking is installed to provide secure attachment for accessory items such as gravel stops and metal sleeves, as stated in Section 5.3.
📌 How should design details be confirmed?
According to Section 5.1, the membrane system supplier or system applicator should provide shop drawings of each condition to confirm field conditions and verify understanding of the design intent.