All rooflite soils are sold with a known and verifiable compaction factor of 15%

Why is compaction important when calculating and purchasing green roof soil for your next project?

Let’s start with green roof soil itself, which is a blend of lightweight aggregates and organic matter components. Depending on the composition and moisture content within the media, more or less air will be retained in the loose product. This air content will change during transportation, installation, and when exposed to the elements. These changes will affect the volume of shipments and the depth of installed green roofs until the growth media has reached a settled compressed state. The challenge the industry faces is how to reliably and consistently measure the bulk density of a growth media in a settled compressed state.

Currently most manufacturers measure the loose state of media and sell as-is, leaving the onus of measuring compaction on the installer; or they approximate a percentage for compaction independent of air or moisture content in the media they sell. But not rooflite, not anymore. Using scientific methods Skyland USA has developed a nonproprietary open source test method (PDF) that effectively and efficiently determines the compressed bulk density* of any green roof soil sample. By using standardized laboratory equipment including a fixed volume mold and proctor hammer, test results can be used as a reliable basis for verifying volume calculations as they relate to material demand, orders, and shipments. Effective immediately, this method is freely available with registration.

And as a value added service to our clients and partners, Skyland USA has taken this test method a step further and now proudly offers an online tool to easily calculate your Compressed Density online. With reliable scientific compressed density testing we can confirm quantities after compression and settling occurs and use those as the basis for verifying all volumes.

So why is compaction important? To ensure you get what you need with precision – scientifically verified.

Ready to estimate your rooflite soil quantity for your project?

Visit the free online green roof media volume calculator.

* Note: this method does not determine the bulk density at max. water-holding capacity according to ASTM E2399