Purple-Roof Green Roof Construction Details


total thicknessN/A
dry weightN/AFLL B.2 & ASTM E-2399
max dead load (wet)N/AFLL B.2 & ASTM E-2399
max retention storage volumeN/AFLL B.2 & ASTM E2399
max detention storage volumeN/AGRD 2151
typical plant palette

Disclaimers: The widget above allows a lot of combinations! These combinations and other information on this page are provided for convenience, and does not to replace the judgment of a licensed design professional. Not all details are suitable for every project. The table of properties above (weights, storage volumes, etc.) includes only approximate values to be used for planning purposes, as exact values may vary. The designations of dead load and live load on this page are consistent with ASTM E-2399, but actual project-specific determination of which weights consitute dead load or live load should be made by a licensed structural engineer. Any flow rates shown on this page are general estimates based on prototypical conditions and are provided for the sole purpose of providing order-of-magnitude estimates; contact us for project-specific modeling required to determine project-specific flow rates. Contact us or one of our partners for specific values or for assistance in selecting appropriate details.

Our green roof construction detail generator is capable of creating approximately 20,000 unique versions of the most commonly used green roof details:

  • Typical details
  • Border conditions (such as gravel or paver borders),
  • Edging conditions (including curbing),
  • Roof drain details, and
  • Other common details such as pipe penetrations.

Details on this page address all common built-in-place (in-situ) green roofs, including traditional green roofs, the Sponge-Roof concept, and the Purple-Roof concept.

You can print this page as a "detail data sheet", link to individual components from the legend, and share links to specific details.

In developing these details, we re-examined all prior assumptions about what makes a great construction detail.

Please contact us if you have any questions about green roof construction details and/or specifications for your project. Want to submit feedback anonymously? Click "share" and let us know how we could make these details better.

In developing these details, we re-examined all prior assumptions about what makes a great construction detail.

Clarity and specificity. Construction details become legal documents once incorporated into bid packages and contract documents. Crisp lines and clear dimensions are important. On the other hand, clarity to a broad audience is often best achieved through color drawings versus black-and-white line drawings. For these reasons, we have attempted to marry crisp line drawings and an illustrative presentation technique so that these details can be used in effective communication by all parties involved, without losing any of the specificity required of construction documentation. All critical components should also be labeled, with critical dimensions provided (via legend in this case).

Brevity. We think construction documents should avoid any unnecessary information. Our green roof construction details show a limited number of components and focus on the relationship between those components. We try to show and label what is important prominently.

Scale vs Relationships. Though some construction details should always be drawn to scale, roofing and green roof details are often best if not drawn to exact scale. Green roof (and waterproofing) details utilize many thin layers, which might not be legible if drawn to scale. We try to think of green roof details more as diagrams than perfect scale drawings.

Clearly scoped. We are providing green roof details, not waterproofing details. For this reason, all associated building-envelope components (structural deck, waterproofing, insulation) are depicted as simplistic diagrams. We strongly recommend maintaining separately scoped details like this throughout the life cycle of construction documents. This allows for the waterproofing to be detailed perfectly elsewhere, and for the green roof to be detailed perfectly here. From a construction inspection perspective, these two systems are independent. I.e. the waterproofing will be fully completed and inspected before the green roof installation begins.

Coordinated. Provide critical information in as few places as possible to avoid miscoordination. Also, ensure green roof details are coordinated with technical specifications. Use the exact same terms on the details as used in the specs. Do not repeat the specs on the drawings. The specs should address quality control, physical properties. Drawings should show dimensions and interrelationships of materials.

Using these green roof construction details

Currently, our construction details are available as PDFs. You should be able to use these details as-is by importing the PDF into AutoCAD.

We hope these details provide a good experience, and help explain the profiles better than black-and-white line drawings. The details are natively created with SVGs, and thus far we haven't found a suitable web-compatible SVG-to-DWG converter, nor have we had time to build one. We had some tough decisions to make regarding whether to focus on high-quality interactive graphics or native AutoCAD format. We hope you'll agree that we made the right choice.