Testing Compressed Density of Green Roof Media

The rooflite method for testing compressed density is an open source tool that lets you determine the settled compressed bulk density of any green roof soil sample. You’ll need a specific set of equipment to accurately test for compressed density, and you’ll need to follow procedures for a set of green roof media samples.


  • Cylindrical mold with an inside diameter of 150 mm and a height of 22.90 cm
  • Steel plate, 5 mm thick, diameter 148 mm (plus magnet for removal from mold)
  • Proctor hammer: 4.5 kg weight, 450 mm drop height
  • 3 small pails (5 Quart)
  • Hand trowel and brush for cleaning
  • Metric ruler
  • Ruler or paint stick
  • Digital scale with at least 15 kg (30 lb) capacity and 2 g readability

NOTE: All items contained in the equipment list are available through independent merchants. However, if you are interested in purchasing these items as a complete kit, please contact your Skyland Sales Representative for more information.



Take 3 representative samples of the green roof media (5 Quarts each).
In the calculator below, complete the Weight of Mold, Volume of Mold and Depth of Mold fields.

For each sample take the following steps:

  • Fill the sample gently into the mold going over the top
  • Scrape off surplus material with the ruler
  • Measure the weight of the sample including the weight of the mold in grams
  • Insert this value into Weight of filled mold without disc field (below)
  • Carefully place steel disc on top of sample
  • Use proctor hammer to compact sample with 3 strikes
  • Remove steel plate (with magnet)
  • Measure average distance between surface of compressed media and the rim of the mold in centimeter
  • Insert this value into Compaction after 3 hammer strikes field (below)
  • Empty mold


Compaction Calculator

* Required fields

First Name *

Last Name *

E-mail *



Company *

Join mailing list (We send occasional emails to share news, updates & events.)